Merge github.com:grpc/grpc into enable-epoll1

134 files changed, 1804 insertions, 4863 deletions

diff --git a/src/core/lib/iomgr/closure.c b/src/core/lib/iomgr/closure.c
index 8ef0b210ad..72a1b20443 100644
--- a/src/core/lib/iomgr/closure.c
+++ b/src/core/lib/iomgr/closure.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 2bedbf00d6..25086fa483 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/combiner.c b/src/core/lib/iomgr/combiner.c
index 863f22c614..f6976c5650 100644
--- a/src/core/lib/iomgr/combiner.c
+++ b/src/core/lib/iomgr/combiner.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -39,7 +24,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/lib/iomgr/workqueue.h"
+#include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/profiling/timers.h"
 
 grpc_tracer_flag grpc_combiner_trace = GRPC_TRACER_INITIALIZER(false);
@@ -56,93 +41,47 @@ grpc_tracer_flag grpc_combiner_trace = GRPC_TRACER_INITIALIZER(false);
 
 struct grpc_combiner {
   grpc_combiner *next_combiner_on_this_exec_ctx;
-  grpc_workqueue *optional_workqueue;
-  grpc_closure_scheduler uncovered_scheduler;
-  grpc_closure_scheduler covered_scheduler;
-  grpc_closure_scheduler uncovered_finally_scheduler;
-  grpc_closure_scheduler covered_finally_scheduler;
+  grpc_closure_scheduler scheduler;
+  grpc_closure_scheduler finally_scheduler;
   gpr_mpscq queue;
+  // either:
+  // a pointer to the initiating exec ctx if that is the only exec_ctx that has
+  // ever queued to this combiner, or NULL. If this is non-null, it's not
+  // dereferencable (since the initiating exec_ctx may have gone out of scope)
+  gpr_atm initiating_exec_ctx_or_null;
   // state is:
   // lower bit - zero if orphaned (STATE_UNORPHANED)
   // other bits - number of items queued on the lock (STATE_ELEM_COUNT_LOW_BIT)
   gpr_atm state;
-  // number of elements in the list that are covered by a poller: if >0, we can
-  // offload safely
-  gpr_atm elements_covered_by_poller;
   bool time_to_execute_final_list;
-  bool final_list_covered_by_poller;
   grpc_closure_list final_list;
   grpc_closure offload;
   gpr_refcount refs;
 };
 
-static void combiner_exec_uncovered(grpc_exec_ctx *exec_ctx,
-                                    grpc_closure *closure, grpc_error *error);
-static void combiner_exec_covered(grpc_exec_ctx *exec_ctx,
+static void combiner_exec(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
+                          grpc_error *error);
+static void combiner_finally_exec(grpc_exec_ctx *exec_ctx,
                                   grpc_closure *closure, grpc_error *error);
-static void combiner_finally_exec_uncovered(grpc_exec_ctx *exec_ctx,
-                                            grpc_closure *closure,
-                                            grpc_error *error);
-static void combiner_finally_exec_covered(grpc_exec_ctx *exec_ctx,
-                                          grpc_closure *closure,
-                                          grpc_error *error);
-
-static const grpc_closure_scheduler_vtable scheduler_uncovered = {
-    combiner_exec_uncovered, combiner_exec_uncovered,
-    "combiner:immediately:uncovered"};
-static const grpc_closure_scheduler_vtable scheduler_covered = {
-    combiner_exec_covered, combiner_exec_covered,
-    "combiner:immediately:covered"};
-static const grpc_closure_scheduler_vtable finally_scheduler_uncovered = {
-    combiner_finally_exec_uncovered, combiner_finally_exec_uncovered,
-    "combiner:finally:uncovered"};
-static const grpc_closure_scheduler_vtable finally_scheduler_covered = {
-    combiner_finally_exec_covered, combiner_finally_exec_covered,
-    "combiner:finally:covered"};
 
-static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
-
-typedef struct {
-  grpc_error *error;
-  bool covered_by_poller;
-} error_data;
-
-static uintptr_t pack_error_data(error_data d) {
-  return ((uintptr_t)d.error) | (d.covered_by_poller ? 1 : 0);
-}
-
-static error_data unpack_error_data(uintptr_t p) {
-  return (error_data){(grpc_error *)(p & ~(uintptr_t)1), p & 1};
-}
+static const grpc_closure_scheduler_vtable scheduler = {
+    combiner_exec, combiner_exec, "combiner:immediately"};
+static const grpc_closure_scheduler_vtable finally_scheduler = {
+    combiner_finally_exec, combiner_finally_exec, "combiner:finally"};
 
-static bool is_covered_by_poller(grpc_combiner *lock) {
-  return lock->final_list_covered_by_poller ||
-         gpr_atm_acq_load(&lock->elements_covered_by_poller) > 0;
-}
-
-#define IS_COVERED_BY_POLLER_FMT "(final=%d elems=%" PRIdPTR ")->%d"
-#define IS_COVERED_BY_POLLER_ARGS(lock)                      \
-  (lock)->final_list_covered_by_poller,                      \
-      gpr_atm_acq_load(&(lock)->elements_covered_by_poller), \
-      is_covered_by_poller((lock))
+static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
 
-grpc_combiner *grpc_combiner_create(grpc_workqueue *optional_workqueue) {
+grpc_combiner *grpc_combiner_create(void) {
   grpc_combiner *lock = gpr_malloc(sizeof(*lock));
   gpr_ref_init(&lock->refs, 1);
   lock->next_combiner_on_this_exec_ctx = NULL;
   lock->time_to_execute_final_list = false;
-  lock->optional_workqueue = optional_workqueue;
-  lock->final_list_covered_by_poller = false;
-  lock->uncovered_scheduler.vtable = &scheduler_uncovered;
-  lock->covered_scheduler.vtable = &scheduler_covered;
-  lock->uncovered_finally_scheduler.vtable = &finally_scheduler_uncovered;
-  lock->covered_finally_scheduler.vtable = &finally_scheduler_covered;
+  lock->scheduler.vtable = &scheduler;
+  lock->finally_scheduler.vtable = &finally_scheduler;
   gpr_atm_no_barrier_store(&lock->state, STATE_UNORPHANED);
-  gpr_atm_no_barrier_store(&lock->elements_covered_by_poller, 0);
   gpr_mpscq_init(&lock->queue);
   grpc_closure_list_init(&lock->final_list);
-  grpc_closure_init(&lock->offload, offload, lock,
-                    grpc_workqueue_scheduler(lock->optional_workqueue));
+  grpc_closure_init(&lock->offload, offload, lock, grpc_executor_scheduler);
   GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p create", lock));
   return lock;
 }
@@ -151,7 +90,6 @@ static void really_destroy(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
   GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p really_destroy", lock));
   GPR_ASSERT(gpr_atm_no_barrier_load(&lock->state) == 0);
   gpr_mpscq_destroy(&lock->queue);
-  GRPC_WORKQUEUE_UNREF(exec_ctx, lock->optional_workqueue, "combiner");
   gpr_free(lock);
 }
 
@@ -208,48 +146,40 @@ static void push_first_on_exec_ctx(grpc_exec_ctx *exec_ctx,
   }
 }
 
-static void combiner_exec(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
-                          grpc_closure *cl, grpc_error *error,
-                          bool covered_by_poller) {
+#define COMBINER_FROM_CLOSURE_SCHEDULER(closure, scheduler_name) \
+  ((grpc_combiner *)(((char *)((closure)->scheduler)) -          \
+                     offsetof(grpc_combiner, scheduler_name)))
+
+static void combiner_exec(grpc_exec_ctx *exec_ctx, grpc_closure *cl,
+                          grpc_error *error) {
   GPR_TIMER_BEGIN("combiner.execute", 0);
+  grpc_combiner *lock = COMBINER_FROM_CLOSURE_SCHEDULER(cl, scheduler);
   gpr_atm last = gpr_atm_full_fetch_add(&lock->state, STATE_ELEM_COUNT_LOW_BIT);
-  GRPC_COMBINER_TRACE(gpr_log(
-      GPR_DEBUG, "C:%p grpc_combiner_execute c=%p cov=%d last=%" PRIdPTR, lock,
-      cl, covered_by_poller, last));
-  GPR_ASSERT(last & STATE_UNORPHANED);  // ensure lock has not been destroyed
-  assert(cl->cb);
-  cl->error_data.scratch =
-      pack_error_data((error_data){error, covered_by_poller});
-  if (covered_by_poller) {
-    gpr_atm_no_barrier_fetch_add(&lock->elements_covered_by_poller, 1);
-  }
-  gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
+  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
+                              "C:%p grpc_combiner_execute c=%p last=%" PRIdPTR,
+                              lock, cl, last));
   if (last == 1) {
+    gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null,
+                             (gpr_atm)exec_ctx);
     // first element on this list: add it to the list of combiner locks
     // executing within this exec_ctx
     push_last_on_exec_ctx(exec_ctx, lock);
+  } else {
+    // there may be a race with setting here: if that happens, we may delay
+    // offload for one or two actions, and that's fine
+    gpr_atm initiator =
+        gpr_atm_no_barrier_load(&lock->initiating_exec_ctx_or_null);
+    if (initiator != 0 && initiator != (gpr_atm)exec_ctx) {
+      gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null, 0);
+    }
   }
+  GPR_ASSERT(last & STATE_UNORPHANED);  // ensure lock has not been destroyed
+  assert(cl->cb);
+  cl->error_data.error = error;
+  gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
   GPR_TIMER_END("combiner.execute", 0);
 }
 
-#define COMBINER_FROM_CLOSURE_SCHEDULER(closure, scheduler_name) \
-  ((grpc_combiner *)(((char *)((closure)->scheduler)) -          \
-                     offsetof(grpc_combiner, scheduler_name)))
-
-static void combiner_exec_uncovered(grpc_exec_ctx *exec_ctx, grpc_closure *cl,
-                                    grpc_error *error) {
-  combiner_exec(exec_ctx,
-                COMBINER_FROM_CLOSURE_SCHEDULER(cl, uncovered_scheduler), cl,
-                error, false);
-}
-
-static void combiner_exec_covered(grpc_exec_ctx *exec_ctx, grpc_closure *cl,
-                                  grpc_error *error) {
-  combiner_exec(exec_ctx,
-                COMBINER_FROM_CLOSURE_SCHEDULER(cl, covered_scheduler), cl,
-                error, true);
-}
-
 static void move_next(grpc_exec_ctx *exec_ctx) {
   exec_ctx->active_combiner =
       exec_ctx->active_combiner->next_combiner_on_this_exec_ctx;
@@ -265,8 +195,7 @@ static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
 
 static void queue_offload(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
   move_next(exec_ctx);
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p queue_offload --> %p", lock,
-                              lock->optional_workqueue));
+  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p queue_offload", lock));
   grpc_closure_sched(exec_ctx, &lock->offload, GRPC_ERROR_NONE);
 }
 
@@ -278,22 +207,23 @@ bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx) {
     return false;
   }
 
-  GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG,
-              "C:%p grpc_combiner_continue_exec_ctx workqueue=%p "
-              "is_covered_by_poller=" IS_COVERED_BY_POLLER_FMT
-              " exec_ctx_ready_to_finish=%d "
-              "time_to_execute_final_list=%d",
-              lock, lock->optional_workqueue, IS_COVERED_BY_POLLER_ARGS(lock),
-              grpc_exec_ctx_ready_to_finish(exec_ctx),
-              lock->time_to_execute_final_list));
-
-  if (lock->optional_workqueue != NULL && is_covered_by_poller(lock) &&
-      grpc_exec_ctx_ready_to_finish(exec_ctx)) {
+  bool contended =
+      gpr_atm_no_barrier_load(&lock->initiating_exec_ctx_or_null) == 0;
+
+  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
+                              "C:%p grpc_combiner_continue_exec_ctx "
+                              "contended=%d "
+                              "exec_ctx_ready_to_finish=%d "
+                              "time_to_execute_final_list=%d",
+                              lock, contended,
+                              grpc_exec_ctx_ready_to_finish(exec_ctx),
+                              lock->time_to_execute_final_list));
+
+  if (contended && grpc_exec_ctx_ready_to_finish(exec_ctx) &&
+      grpc_executor_is_threaded()) {
     GPR_TIMER_MARK("offload_from_finished_exec_ctx", 0);
-    // this execution context wants to move on, and we have a workqueue (and
-    // so can help the execution context out): schedule remaining work to be
-    // picked up on the workqueue
+    // this execution context wants to move on: schedule remaining work to be
+    // picked up on the executor
     queue_offload(exec_ctx, lock);
     GPR_TIMER_END("combiner.continue_exec_ctx", 0);
     return true;
@@ -310,29 +240,23 @@ bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx) {
       // queue is in an inconsistent state: use this as a cue that we should
       // go off and do something else for a while (and come back later)
       GPR_TIMER_MARK("delay_busy", 0);
-      if (lock->optional_workqueue != NULL && is_covered_by_poller(lock)) {
-        queue_offload(exec_ctx, lock);
-      }
+      queue_offload(exec_ctx, lock);
       GPR_TIMER_END("combiner.continue_exec_ctx", 0);
       return true;
     }
     GPR_TIMER_BEGIN("combiner.exec1", 0);
     grpc_closure *cl = (grpc_closure *)n;
-    error_data err = unpack_error_data(cl->error_data.scratch);
+    grpc_error *cl_err = cl->error_data.error;
 #ifndef NDEBUG
     cl->scheduled = false;
 #endif
-    cl->cb(exec_ctx, cl->cb_arg, err.error);
-    if (err.covered_by_poller) {
-      gpr_atm_no_barrier_fetch_add(&lock->elements_covered_by_poller, -1);
-    }
-    GRPC_ERROR_UNREF(err.error);
+    cl->cb(exec_ctx, cl->cb_arg, cl_err);
+    GRPC_ERROR_UNREF(cl_err);
     GPR_TIMER_END("combiner.exec1", 0);
   } else {
     grpc_closure *c = lock->final_list.head;
     GPR_ASSERT(c != NULL);
     grpc_closure_list_init(&lock->final_list);
-    lock->final_list_covered_by_poller = false;
     int loops = 0;
     while (c != NULL) {
       GPR_TIMER_BEGIN("combiner.exec_1final", 0);
@@ -398,20 +322,20 @@ bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx) {
 static void enqueue_finally(grpc_exec_ctx *exec_ctx, void *closure,
                             grpc_error *error);
 
-static void combiner_execute_finally(grpc_exec_ctx *exec_ctx,
-                                     grpc_combiner *lock, grpc_closure *closure,
-                                     grpc_error *error,
-                                     bool covered_by_poller) {
-  GRPC_COMBINER_TRACE(gpr_log(
-      GPR_DEBUG, "C:%p grpc_combiner_execute_finally c=%p; ac=%p; cov=%d", lock,
-      closure, exec_ctx->active_combiner, covered_by_poller));
+static void combiner_finally_exec(grpc_exec_ctx *exec_ctx,
+                                  grpc_closure *closure, grpc_error *error) {
+  grpc_combiner *lock =
+      COMBINER_FROM_CLOSURE_SCHEDULER(closure, finally_scheduler);
+  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
+                              "C:%p grpc_combiner_execute_finally c=%p; ac=%p",
+                              lock, closure, exec_ctx->active_combiner));
   GPR_TIMER_BEGIN("combiner.execute_finally", 0);
   if (exec_ctx->active_combiner != lock) {
     GPR_TIMER_MARK("slowpath", 0);
-    grpc_closure_sched(
-        exec_ctx, grpc_closure_create(enqueue_finally, closure,
-                                      grpc_combiner_scheduler(lock, false)),
-        error);
+    grpc_closure_sched(exec_ctx,
+                       grpc_closure_create(enqueue_finally, closure,
+                                           grpc_combiner_scheduler(lock)),
+                       error);
     GPR_TIMER_END("combiner.execute_finally", 0);
     return;
   }
@@ -419,42 +343,20 @@ static void combiner_execute_finally(grpc_exec_ctx *exec_ctx,
   if (grpc_closure_list_empty(lock->final_list)) {
     gpr_atm_full_fetch_add(&lock->state, STATE_ELEM_COUNT_LOW_BIT);
   }
-  if (covered_by_poller) {
-    lock->final_list_covered_by_poller = true;
-  }
   grpc_closure_list_append(&lock->final_list, closure, error);
   GPR_TIMER_END("combiner.execute_finally", 0);
 }
 
 static void enqueue_finally(grpc_exec_ctx *exec_ctx, void *closure,
                             grpc_error *error) {
-  combiner_execute_finally(exec_ctx, exec_ctx->active_combiner, closure,
-                           GRPC_ERROR_REF(error), false);
-}
-
-static void combiner_finally_exec_uncovered(grpc_exec_ctx *exec_ctx,
-                                            grpc_closure *cl,
-                                            grpc_error *error) {
-  combiner_execute_finally(exec_ctx, COMBINER_FROM_CLOSURE_SCHEDULER(
-                                         cl, uncovered_finally_scheduler),
-                           cl, error, false);
-}
-
-static void combiner_finally_exec_covered(grpc_exec_ctx *exec_ctx,
-                                          grpc_closure *cl, grpc_error *error) {
-  combiner_execute_finally(
-      exec_ctx, COMBINER_FROM_CLOSURE_SCHEDULER(cl, covered_finally_scheduler),
-      cl, error, true);
+  combiner_finally_exec(exec_ctx, closure, GRPC_ERROR_REF(error));
 }
 
-grpc_closure_scheduler *grpc_combiner_scheduler(grpc_combiner *combiner,
-                                                bool covered_by_poller) {
-  return covered_by_poller ? &combiner->covered_scheduler
-                           : &combiner->uncovered_scheduler;
+grpc_closure_scheduler *grpc_combiner_scheduler(grpc_combiner *combiner) {
+  return &combiner->scheduler;
 }
 
 grpc_closure_scheduler *grpc_combiner_finally_scheduler(
-    grpc_combiner *combiner, bool covered_by_poller) {
-  return covered_by_poller ? &combiner->covered_finally_scheduler
-                           : &combiner->uncovered_finally_scheduler;
+    grpc_combiner *combiner) {
+  return &combiner->finally_scheduler;
 }
diff --git a/src/core/lib/iomgr/combiner.h b/src/core/lib/iomgr/combiner.h
index 6ab7a2b26b..a616113ca0 100644
--- a/src/core/lib/iomgr/combiner.h
+++ b/src/core/lib/iomgr/combiner.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -48,7 +33,7 @@
 
 // Initialize the lock, with an optional workqueue to shift load to when
 // necessary
-grpc_combiner *grpc_combiner_create(grpc_workqueue *optional_workqueue);
+grpc_combiner *grpc_combiner_create(void);
 
 //#define GRPC_COMBINER_REFCOUNT_DEBUG
 #ifdef GRPC_COMBINER_REFCOUNT_DEBUG
@@ -71,11 +56,9 @@ grpc_combiner *grpc_combiner_ref(grpc_combiner *lock GRPC_COMBINER_DEBUG_ARGS);
 void grpc_combiner_unref(grpc_exec_ctx *exec_ctx,
                          grpc_combiner *lock GRPC_COMBINER_DEBUG_ARGS);
 // Fetch a scheduler to schedule closures against
-grpc_closure_scheduler *grpc_combiner_scheduler(grpc_combiner *lock,
-                                                bool covered_by_poller);
+grpc_closure_scheduler *grpc_combiner_scheduler(grpc_combiner *lock);
 // Scheduler to execute \a action within the lock just prior to unlocking.
-grpc_closure_scheduler *grpc_combiner_finally_scheduler(grpc_combiner *lock,
-                                                        bool covered_by_poller);
+grpc_closure_scheduler *grpc_combiner_finally_scheduler(grpc_combiner *lock);
 
 bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx);
 
diff --git a/src/core/lib/iomgr/endpoint.c b/src/core/lib/iomgr/endpoint.c
index bf6e98146a..37cce335ca 100644
--- a/src/core/lib/iomgr/endpoint.c
+++ b/src/core/lib/iomgr/endpoint.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -69,10 +54,6 @@ char* grpc_endpoint_get_peer(grpc_endpoint* ep) {
 
 int grpc_endpoint_get_fd(grpc_endpoint* ep) { return ep->vtable->get_fd(ep); }
 
-grpc_workqueue* grpc_endpoint_get_workqueue(grpc_endpoint* ep) {
-  return ep->vtable->get_workqueue(ep);
-}
-
 grpc_resource_user* grpc_endpoint_get_resource_user(grpc_endpoint* ep) {
   return ep->vtable->get_resource_user(ep);
 }
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index 740357ecc5..8f0523a981 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -52,7 +37,6 @@ struct grpc_endpoint_vtable {
                grpc_slice_buffer *slices, grpc_closure *cb);
   void (*write)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                 grpc_slice_buffer *slices, grpc_closure *cb);
-  grpc_workqueue *(*get_workqueue)(grpc_endpoint *ep);
   void (*add_to_pollset)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                          grpc_pollset *pollset);
   void (*add_to_pollset_set)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
@@ -78,9 +62,6 @@ char *grpc_endpoint_get_peer(grpc_endpoint *ep);
    */
 int grpc_endpoint_get_fd(grpc_endpoint *ep);
 
-/* Retrieve a reference to the workqueue associated with this endpoint */
-grpc_workqueue *grpc_endpoint_get_workqueue(grpc_endpoint *ep);
-
 /* Write slices out to the socket.
 
    If the connection is ready for more data after the end of the call, it
diff --git a/src/core/lib/iomgr/endpoint_pair.h b/src/core/lib/iomgr/endpoint_pair.h
index 6407a6ad3f..b60e62fc3e 100644
--- a/src/core/lib/iomgr/endpoint_pair.h
+++ b/src/core/lib/iomgr/endpoint_pair.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/endpoint_pair_posix.c b/src/core/lib/iomgr/endpoint_pair_posix.c
index 5542a372d8..3ade2148ba 100644
--- a/src/core/lib/iomgr/endpoint_pair_posix.c
+++ b/src/core/lib/iomgr/endpoint_pair_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/endpoint_pair_uv.c b/src/core/lib/iomgr/endpoint_pair_uv.c
index 9718eb0523..ff72fe0492 100644
--- a/src/core/lib/iomgr/endpoint_pair_uv.c
+++ b/src/core/lib/iomgr/endpoint_pair_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/endpoint_pair_windows.c b/src/core/lib/iomgr/endpoint_pair_windows.c
index 25d6264dfb..782fa2fd69 100644
--- a/src/core/lib/iomgr/endpoint_pair_windows.c
+++ b/src/core/lib/iomgr/endpoint_pair_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/error.c b/src/core/lib/iomgr/error.c
index 685581b5cb..68884226b5 100644
--- a/src/core/lib/iomgr/error.c
+++ b/src/core/lib/iomgr/error.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/error.h b/src/core/lib/iomgr/error.h
index 34b24d9263..e626845fa4 100644
--- a/src/core/lib/iomgr/error.h
+++ b/src/core/lib/iomgr/error.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/error_internal.h b/src/core/lib/iomgr/error_internal.h
index 7f204df1b2..7507484557 100644
--- a/src/core/lib/iomgr/error_internal.h
+++ b/src/core/lib/iomgr/error_internal.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.c b/src/core/lib/iomgr/ev_epoll1_linux.c
index 379b875014..3792823560 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.c
+++ b/src/core/lib/iomgr/ev_epoll1_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -58,7 +43,6 @@
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/string.h"
@@ -150,7 +134,9 @@ struct grpc_pollset {
  * Pollset-set Declarations
  */
 
-struct grpc_pollset_set {};
+struct grpc_pollset_set {
+  char unused;
+};
 
 /*******************************************************************************
  * Common helpers
@@ -303,10 +289,6 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure, "write");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
-  return (grpc_workqueue *)0xb0b51ed;
-}
-
 static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                                grpc_pollset *notifier) {
   grpc_lfev_set_ready(exec_ctx, &fd->read_closure, "read");
@@ -333,8 +315,6 @@ GPR_TLS_DECL(g_current_thread_worker);
 static gpr_atm g_active_poller;
 static pollset_neighbourhood *g_neighbourhoods;
 static size_t g_num_neighbourhoods;
-static gpr_mu g_wq_mu;
-static grpc_closure_list g_wq_items;
 
 /* Return true if first in list */
 static bool worker_insert(grpc_pollset *pollset, grpc_pollset_worker *worker) {
@@ -383,8 +363,6 @@ static grpc_error *pollset_global_init(void) {
   gpr_atm_no_barrier_store(&g_active_poller, 0);
   global_wakeup_fd.read_fd = -1;
   grpc_error *err = grpc_wakeup_fd_init(&global_wakeup_fd);
-  gpr_mu_init(&g_wq_mu);
-  g_wq_items = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT;
   if (err != GRPC_ERROR_NONE) return err;
   struct epoll_event ev = {.events = (uint32_t)(EPOLLIN | EPOLLET),
                            .data.ptr = &global_wakeup_fd};
@@ -403,7 +381,6 @@ static grpc_error *pollset_global_init(void) {
 static void pollset_global_shutdown(void) {
   gpr_tls_destroy(&g_current_thread_pollset);
   gpr_tls_destroy(&g_current_thread_worker);
-  gpr_mu_destroy(&g_wq_mu);
   if (global_wakeup_fd.read_fd != -1) grpc_wakeup_fd_destroy(&global_wakeup_fd);
   for (size_t i = 0; i < g_num_neighbourhoods; i++) {
     gpr_mu_destroy(&g_neighbourhoods[i].mu);
@@ -536,9 +513,6 @@ static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
   for (int i = 0; i < r; i++) {
     void *data_ptr = events[i].data.ptr;
     if (data_ptr == &global_wakeup_fd) {
-      gpr_mu_lock(&g_wq_mu);
-      grpc_closure_list_move(&g_wq_items, &exec_ctx->closure_list);
-      gpr_mu_unlock(&g_wq_mu);
       append_error(&error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd),
                    err_desc);
     } else {
@@ -952,84 +926,6 @@ static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
                            grpc_fd *fd) {}
 
 /*******************************************************************************
- * Workqueue Definitions
- */
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {}
-#endif
-
-static void wq_sched(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                     grpc_error *error) {
-  // find a neighbourhood to wakeup
-  bool scheduled = false;
-  size_t initial_neighbourhood = choose_neighbourhood();
-  for (size_t i = 0; !scheduled && i < g_num_neighbourhoods; i++) {
-    pollset_neighbourhood *neighbourhood =
-        &g_neighbourhoods[(initial_neighbourhood + i) % g_num_neighbourhoods];
-    if (gpr_mu_trylock(&neighbourhood->mu)) {
-      if (neighbourhood->active_root != NULL) {
-        grpc_pollset *inspect = neighbourhood->active_root;
-        do {
-          if (gpr_mu_trylock(&inspect->mu)) {
-            if (inspect->root_worker != NULL) {
-              grpc_pollset_worker *inspect_worker = inspect->root_worker;
-              do {
-                if (inspect_worker->kick_state == UNKICKED) {
-                  SET_KICK_STATE(inspect_worker, KICKED);
-                  grpc_closure_list_append(
-                      &inspect_worker->schedule_on_end_work, closure, error);
-                  if (inspect_worker->initialized_cv) {
-                    gpr_cv_signal(&inspect_worker->cv);
-                  }
-                  scheduled = true;
-                }
-                inspect_worker = inspect_worker->next;
-              } while (!scheduled && inspect_worker != inspect->root_worker);
-            }
-            gpr_mu_unlock(&inspect->mu);
-          }
-          inspect = inspect->next;
-        } while (!scheduled && inspect != neighbourhood->active_root);
-      }
-      gpr_mu_unlock(&neighbourhood->mu);
-    }
-  }
-  if (!scheduled) {
-    gpr_mu_lock(&g_wq_mu);
-    grpc_closure_list_append(&g_wq_items, closure, error);
-    gpr_mu_unlock(&g_wq_mu);
-    GRPC_LOG_IF_ERROR("workqueue_scheduler",
-                      grpc_wakeup_fd_wakeup(&global_wakeup_fd));
-  }
-}
-
-static const grpc_closure_scheduler_vtable
-    singleton_workqueue_scheduler_vtable = {wq_sched, wq_sched,
-                                            "epoll1_workqueue"};
-
-static grpc_closure_scheduler singleton_workqueue_scheduler = {
-    &singleton_workqueue_scheduler_vtable};
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  return &singleton_workqueue_scheduler;
-}
-
-/*******************************************************************************
  * Pollset-set Definitions
  */
 
@@ -1080,7 +976,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -1098,10 +993,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.h b/src/core/lib/iomgr/ev_epoll1_linux.h
index bd52478a7c..0696e0df40 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.h
+++ b/src/core/lib/iomgr/ev_epoll1_linux.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.c b/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.c
index 4a17f7d07c..0ed37b9899 100644
--- a/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -61,7 +46,6 @@
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/env.h"
@@ -184,13 +168,15 @@ static void fd_global_shutdown(void);
  * Polling island Declarations
  */
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+//#define PI_REFCOUNT_DEBUG
+
+#ifdef PI_REFCOUNT_DEBUG
 
 #define PI_ADD_REF(p, r) pi_add_ref_dbg((p), (r), __FILE__, __LINE__)
 #define PI_UNREF(exec_ctx, p, r) \
   pi_unref_dbg((exec_ctx), (p), (r), __FILE__, __LINE__)
 
-#else /* defined(GRPC_WORKQUEUE_REFCOUNT_DEBUG) */
+#else /* defined(PI_REFCOUNT_DEBUG) */
 
 #define PI_ADD_REF(p, r) pi_add_ref((p))
 #define PI_UNREF(exec_ctx, p, r) pi_unref((exec_ctx), (p))
@@ -204,8 +190,6 @@ typedef struct worker_node {
 
 /* This is also used as grpc_workqueue (by directly casing it) */
 typedef struct polling_island {
-  grpc_closure_scheduler workqueue_scheduler;
-
   gpr_mu mu;
   /* Ref count. Use PI_ADD_REF() and PI_UNREF() macros to increment/decrement
      the refcount.
@@ -226,15 +210,6 @@ typedef struct polling_island {
 
   /* Number of threads currently polling on this island */
   gpr_atm poller_count;
-  /* Mutex guarding the read end of the workqueue (must be held to pop from
-   * workqueue_items) */
-  gpr_mu workqueue_read_mu;
-  /* Queue of closures to be executed */
-  gpr_mpscq workqueue_items;
-  /* Count of items in workqueue_items */
-  gpr_atm workqueue_item_count;
-  /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
-  grpc_wakeup_fd workqueue_wakeup_fd;
 
   /* The list of workers waiting to do polling on this polling island */
   gpr_mu worker_list_mu;
@@ -323,8 +298,6 @@ static __thread polling_island *g_current_thread_polling_island;
 
 /* Forward declaration */
 static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi);
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error);
 
 #ifdef GRPC_TSAN
 /* Currently TSAN may incorrectly flag data races between epoll_ctl and
@@ -337,13 +310,10 @@ static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
 gpr_atm g_epoll_sync;
 #endif /* defined(GRPC_TSAN) */
 
-static const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
-    workqueue_enqueue, workqueue_enqueue, "workqueue"};
-
 static void pi_add_ref(polling_island *pi);
 static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi);
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+#ifdef PI_REFCOUNT_DEBUG
 static void pi_add_ref_dbg(polling_island *pi, const char *reason,
                            const char *file, int line) {
   long old_cnt = gpr_atm_acq_load(&pi->ref_count);
@@ -359,36 +329,6 @@ static void pi_unref_dbg(grpc_exec_ctx *exec_ctx, polling_island *pi,
   gpr_log(GPR_DEBUG, "Unref pi: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
           (void *)pi, old_cnt, (old_cnt - 1), reason, file, line);
 }
-
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  if (workqueue != NULL) {
-    pi_add_ref_dbg((polling_island *)workqueue, reason, file, line);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {
-  if (workqueue != NULL) {
-    pi_unref_dbg(exec_ctx, (polling_island *)workqueue, reason, file, line);
-  }
-}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    pi_add_ref((polling_island *)workqueue);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    pi_unref(exec_ctx, (polling_island *)workqueue);
-  }
-}
 #endif
 
 static void pi_add_ref(polling_island *pi) {
@@ -592,17 +532,12 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
   *error = GRPC_ERROR_NONE;
 
   pi = gpr_malloc(sizeof(*pi));
-  pi->workqueue_scheduler.vtable = &workqueue_scheduler_vtable;
   gpr_mu_init(&pi->mu);
   pi->fd_cnt = 0;
   pi->fd_capacity = 0;
   pi->fds = NULL;
   pi->epoll_fd = -1;
 
-  gpr_mu_init(&pi->workqueue_read_mu);
-  gpr_mpscq_init(&pi->workqueue_items);
-  gpr_atm_rel_store(&pi->workqueue_item_count, 0);
-
   gpr_atm_rel_store(&pi->ref_count, 0);
   gpr_atm_rel_store(&pi->poller_count, 0);
   gpr_atm_rel_store(&pi->merged_to, (gpr_atm)NULL);
@@ -610,11 +545,6 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
   gpr_mu_init(&pi->worker_list_mu);
   worker_node_init(&pi->worker_list_head);
 
-  if (!append_error(error, grpc_wakeup_fd_init(&pi->workqueue_wakeup_fd),
-                    err_desc)) {
-    goto done;
-  }
-
   pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 
   if (pi->epoll_fd < 0) {
@@ -622,8 +552,6 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
     goto done;
   }
 
-  polling_island_add_wakeup_fd_locked(pi, &pi->workqueue_wakeup_fd, error);
-
   if (initial_fd != NULL) {
     polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
   }
@@ -642,11 +570,7 @@ static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi) {
   if (pi->epoll_fd >= 0) {
     close(pi->epoll_fd);
   }
-  GPR_ASSERT(gpr_atm_no_barrier_load(&pi->workqueue_item_count) == 0);
-  gpr_mu_destroy(&pi->workqueue_read_mu);
-  gpr_mpscq_destroy(&pi->workqueue_items);
   gpr_mu_destroy(&pi->mu);
-  grpc_wakeup_fd_destroy(&pi->workqueue_wakeup_fd);
   gpr_mu_destroy(&pi->worker_list_mu);
   GPR_ASSERT(is_worker_node_detached(&pi->worker_list_head));
 
@@ -794,45 +718,6 @@ static void polling_island_unlock_pair(polling_island *p, polling_island *q) {
   }
 }
 
-static void workqueue_maybe_wakeup(polling_island *pi) {
-  /* If this thread is the current poller, then it may be that it's about to
-     decrement the current poller count, so we need to look past this thread */
-  bool is_current_poller = (g_current_thread_polling_island == pi);
-  gpr_atm min_current_pollers_for_wakeup = is_current_poller ? 1 : 0;
-  gpr_atm current_pollers = gpr_atm_no_barrier_load(&pi->poller_count);
-  /* Only issue a wakeup if it's likely that some poller could come in and take
-     it right now. Note that since we do an anticipatory mpscq_pop every poll
-     loop, it's ok if we miss the wakeup here, as we'll get the work item when
-     the next poller enters anyway. */
-  if (current_pollers > min_current_pollers_for_wakeup) {
-    GRPC_LOG_IF_ERROR("workqueue_wakeup_fd",
-                      grpc_wakeup_fd_wakeup(&pi->workqueue_wakeup_fd));
-  }
-}
-
-static void workqueue_move_items_to_parent(polling_island *q) {
-  polling_island *p = (polling_island *)gpr_atm_no_barrier_load(&q->merged_to);
-  if (p == NULL) {
-    return;
-  }
-  gpr_mu_lock(&q->workqueue_read_mu);
-  int num_added = 0;
-  while (gpr_atm_no_barrier_load(&q->workqueue_item_count) > 0) {
-    gpr_mpscq_node *n = gpr_mpscq_pop(&q->workqueue_items);
-    if (n != NULL) {
-      gpr_atm_no_barrier_fetch_add(&q->workqueue_item_count, -1);
-      gpr_atm_no_barrier_fetch_add(&p->workqueue_item_count, 1);
-      gpr_mpscq_push(&p->workqueue_items, n);
-      num_added++;
-    }
-  }
-  gpr_mu_unlock(&q->workqueue_read_mu);
-  if (num_added > 0) {
-    workqueue_maybe_wakeup(p);
-  }
-  workqueue_move_items_to_parent(p);
-}
-
 static polling_island *polling_island_merge(polling_island *p,
                                             polling_island *q,
                                             grpc_error **error) {
@@ -857,8 +742,6 @@ static polling_island *polling_island_merge(polling_island *p,
     /* Add the 'merged_to' link from p --> q */
     gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
     PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
-
-    workqueue_move_items_to_parent(p);
   }
   /* else if p == q, nothing needs to be done */
 
@@ -869,32 +752,6 @@ static polling_island *polling_island_merge(polling_island *p,
   return q;
 }
 
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
-  grpc_workqueue *workqueue = (grpc_workqueue *)closure->scheduler;
-  /* take a ref to the workqueue: otherwise it can happen that whatever events
-   * this kicks off ends up destroying the workqueue before this function
-   * completes */
-  GRPC_WORKQUEUE_REF(workqueue, "enqueue");
-  polling_island *pi = (polling_island *)workqueue;
-  gpr_atm last = gpr_atm_no_barrier_fetch_add(&pi->workqueue_item_count, 1);
-  closure->error_data.error = error;
-  gpr_mpscq_push(&pi->workqueue_items, &closure->next_data.atm_next);
-  if (last == 0) {
-    workqueue_maybe_wakeup(pi);
-  }
-  workqueue_move_items_to_parent(pi);
-  GRPC_WORKQUEUE_UNREF(exec_ctx, workqueue, "enqueue");
-  GPR_TIMER_END("workqueue.enqueue", 0);
-}
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  polling_island *pi = (polling_island *)workqueue;
-  return workqueue == NULL ? grpc_schedule_on_exec_ctx
-                           : &pi->workqueue_scheduler;
-}
-
 static grpc_error *polling_island_global_init() {
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -1153,14 +1010,6 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure, "write");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
-  gpr_mu_lock(&fd->po.mu);
-  grpc_workqueue *workqueue =
-      GRPC_WORKQUEUE_REF((grpc_workqueue *)fd->po.pi, "fd_get_workqueue");
-  gpr_mu_unlock(&fd->po.mu);
-  return workqueue;
-}
-
 /*******************************************************************************
  * Pollset Definitions
  */
@@ -1432,33 +1281,6 @@ static void pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
   gpr_mu_destroy(&pollset->po.mu);
 }
 
-static bool maybe_do_workqueue_work(grpc_exec_ctx *exec_ctx,
-                                    polling_island *pi) {
-  if (gpr_mu_trylock(&pi->workqueue_read_mu)) {
-    gpr_mpscq_node *n = gpr_mpscq_pop(&pi->workqueue_items);
-    gpr_mu_unlock(&pi->workqueue_read_mu);
-    if (n != NULL) {
-      if (gpr_atm_full_fetch_add(&pi->workqueue_item_count, -1) > 1) {
-        workqueue_maybe_wakeup(pi);
-      }
-      grpc_closure *c = (grpc_closure *)n;
-      grpc_error *error = c->error_data.error;
-#ifndef NDEBUG
-      c->scheduled = false;
-#endif
-      c->cb(exec_ctx, c->cb_arg, error);
-      GRPC_ERROR_UNREF(error);
-      return true;
-    } else if (gpr_atm_no_barrier_load(&pi->workqueue_item_count) > 0) {
-      /* n == NULL might mean there's work but it's not available to be popped
-       * yet - try to ensure another workqueue wakes up to check shortly if so
-       */
-      workqueue_maybe_wakeup(pi);
-    }
-  }
-  return false;
-}
-
 /* NOTE: This function may modify 'now' */
 static bool acquire_polling_lease(grpc_pollset_worker *worker,
                                   polling_island *pi, gpr_timespec deadline,
@@ -1594,12 +1416,7 @@ static void pollset_do_epoll_pwait(grpc_exec_ctx *exec_ctx, int epoll_fd,
 
   for (int i = 0; i < ep_rv; ++i) {
     void *data_ptr = ep_ev[i].data.ptr;
-    if (data_ptr == &pi->workqueue_wakeup_fd) {
-      append_error(error,
-                   grpc_wakeup_fd_consume_wakeup(&pi->workqueue_wakeup_fd),
-                   err_desc);
-      maybe_do_workqueue_work(exec_ctx, pi);
-    } else if (data_ptr == &polling_island_wakeup_fd) {
+    if (data_ptr == &polling_island_wakeup_fd) {
       GRPC_POLLING_TRACE(
           "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
           "%d) got merged",
@@ -1675,15 +1492,10 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
   PI_ADD_REF(pi, "ps_work");
   gpr_mu_unlock(&pollset->po.mu);
 
-  /* If we get some workqueue work to do, it might end up completing an item on
-     the completion queue, so there's no need to poll... so we skip that and
-     redo the complete loop to verify */
-  if (!maybe_do_workqueue_work(exec_ctx, pi)) {
-    g_current_thread_polling_island = pi;
-    pollset_do_epoll_pwait(exec_ctx, epoll_fd, pollset, pi, worker, now,
-                           deadline, sig_mask, error);
-    g_current_thread_polling_island = NULL;
-  }
+  g_current_thread_polling_island = pi;
+  pollset_do_epoll_pwait(exec_ctx, epoll_fd, pollset, pi, worker, now, deadline,
+                         sig_mask, error);
+  g_current_thread_polling_island = NULL;
 
   GPR_ASSERT(pi != NULL);
 
@@ -2036,7 +1848,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -2054,10 +1865,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.h b/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.h
index 379e1ded3b..1d6af5f52c 100644
--- a/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.h
+++ b/src/core/lib/iomgr/ev_epoll_limited_pollers_linux.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
index adc5e79644..5d45251983 100644
--- a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -61,7 +46,6 @@
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
 
@@ -109,23 +93,22 @@ static void fd_global_shutdown(void);
  * epoll set Declarations
  */
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+//#define EPS_REFCOUNT_DEBUG
+
+#ifdef EPS_REFCOUNT_DEBUG
 
 #define EPS_ADD_REF(p, r) eps_add_ref_dbg((p), (r), __FILE__, __LINE__)
 #define EPS_UNREF(exec_ctx, p, r) \
   eps_unref_dbg((exec_ctx), (p), (r), __FILE__, __LINE__)
 
-#else /* defined(GRPC_WORKQUEUE_REFCOUNT_DEBUG) */
+#else /* defined(EPS_REFCOUNT_DEBUG) */
 
 #define EPS_ADD_REF(p, r) eps_add_ref((p))
 #define EPS_UNREF(exec_ctx, p, r) eps_unref((exec_ctx), (p))
 
 #endif /* !defined(GRPC_EPS_REF_COUNT_DEBUG) */
 
-/* This is also used as grpc_workqueue (by directly casting it) */
 typedef struct epoll_set {
-  grpc_closure_scheduler workqueue_scheduler;
-
   /* Mutex poller should acquire to poll this. This enforces that only one
    * poller can be polling on epoll_set at any time */
   gpr_mu mu;
@@ -139,15 +122,6 @@ typedef struct epoll_set {
 
   /* Number of threads currently polling on this epoll set*/
   gpr_atm poller_count;
-  /* Mutex guarding the read end of the workqueue (must be held to pop from
-   * workqueue_items) */
-  gpr_mu workqueue_read_mu;
-  /* Queue of closures to be executed */
-  gpr_mpscq workqueue_items;
-  /* Count of items in workqueue_items */
-  gpr_atm workqueue_item_count;
-  /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
-  grpc_wakeup_fd workqueue_wakeup_fd;
 
   /* Is the epoll set shutdown */
   gpr_atm is_shutdown;
@@ -181,7 +155,9 @@ struct grpc_pollset {
 /*******************************************************************************
  * Pollset-set Declarations
  */
-struct grpc_pollset_set {};
+struct grpc_pollset_set {
+  char unused;
+};
 
 /*****************************************************************************
  * Dedicated polling threads and pollsets - Declarations
@@ -235,8 +211,6 @@ static __thread epoll_set *g_current_thread_epoll_set;
 
 /* Forward declaration */
 static void epoll_set_delete(epoll_set *eps);
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error);
 
 #ifdef GRPC_TSAN
 /* Currently TSAN may incorrectly flag data races between epoll_ctl and
@@ -249,13 +223,10 @@ static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
 gpr_atm g_epoll_sync;
 #endif /* defined(GRPC_TSAN) */
 
-static const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
-    workqueue_enqueue, workqueue_enqueue, "workqueue"};
-
 static void eps_add_ref(epoll_set *eps);
 static void eps_unref(grpc_exec_ctx *exec_ctx, epoll_set *eps);
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+#ifdef EPS_REFCOUNT_DEBUG
 static void eps_add_ref_dbg(epoll_set *eps, const char *reason,
                             const char *file, int line) {
   long old_cnt = gpr_atm_acq_load(&eps->ref_count);
@@ -271,36 +242,6 @@ static void eps_unref_dbg(grpc_exec_ctx *exec_ctx, epoll_set *eps,
   gpr_log(GPR_DEBUG, "Unref eps: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
           (void *)eps, old_cnt, (old_cnt - 1), reason, file, line);
 }
-
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  if (workqueue != NULL) {
-    eps_add_ref_dbg((epoll_set *)workqueue, reason, file, line);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {
-  if (workqueue != NULL) {
-    eps_unref_dbg(exec_ctx, (epoll_set *)workqueue, reason, file, line);
-  }
-}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    eps_add_ref((epoll_set *)workqueue);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    eps_unref(exec_ctx, (epoll_set *)workqueue);
-  }
-}
 #endif
 
 static void eps_add_ref(epoll_set *eps) {
@@ -394,24 +335,15 @@ static epoll_set *epoll_set_create(grpc_error **error) {
   *error = GRPC_ERROR_NONE;
 
   eps = gpr_malloc(sizeof(*eps));
-  eps->workqueue_scheduler.vtable = &workqueue_scheduler_vtable;
   eps->epoll_fd = -1;
 
   gpr_mu_init(&eps->mu);
-  gpr_mu_init(&eps->workqueue_read_mu);
-  gpr_mpscq_init(&eps->workqueue_items);
-  gpr_atm_rel_store(&eps->workqueue_item_count, 0);
 
   gpr_atm_rel_store(&eps->ref_count, 0);
   gpr_atm_rel_store(&eps->poller_count, 0);
 
   gpr_atm_rel_store(&eps->is_shutdown, false);
 
-  if (!append_error(error, grpc_wakeup_fd_init(&eps->workqueue_wakeup_fd),
-                    err_desc)) {
-    goto done;
-  }
-
   eps->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 
   if (eps->epoll_fd < 0) {
@@ -419,8 +351,6 @@ static epoll_set *epoll_set_create(grpc_error **error) {
     goto done;
   }
 
-  epoll_set_add_wakeup_fd_locked(eps, &eps->workqueue_wakeup_fd, error);
-
 done:
   if (*error != GRPC_ERROR_NONE) {
     epoll_set_delete(eps);
@@ -434,57 +364,11 @@ static void epoll_set_delete(epoll_set *eps) {
     close(eps->epoll_fd);
   }
 
-  GPR_ASSERT(gpr_atm_no_barrier_load(&eps->workqueue_item_count) == 0);
   gpr_mu_destroy(&eps->mu);
-  gpr_mu_destroy(&eps->workqueue_read_mu);
-  gpr_mpscq_destroy(&eps->workqueue_items);
-  grpc_wakeup_fd_destroy(&eps->workqueue_wakeup_fd);
 
   gpr_free(eps);
 }
 
-static void workqueue_maybe_wakeup(epoll_set *eps) {
-  /* If this thread is the current poller, then it may be that it's about to
-     decrement the current poller count, so we need to look past this thread */
-  bool is_current_poller = (g_current_thread_epoll_set == eps);
-  gpr_atm min_current_pollers_for_wakeup = is_current_poller ? 1 : 0;
-  gpr_atm current_pollers = gpr_atm_no_barrier_load(&eps->poller_count);
-  /* Only issue a wakeup if it's likely that some poller could come in and take
-     it right now. Note that since we do an anticipatory mpscq_pop every poll
-     loop, it's ok if we miss the wakeup here, as we'll get the work item when
-     the next poller enters anyway. */
-  if (current_pollers > min_current_pollers_for_wakeup) {
-    GRPC_LOG_IF_ERROR("workqueue_wakeup_fd",
-                      grpc_wakeup_fd_wakeup(&eps->workqueue_wakeup_fd));
-  }
-}
-
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
-  grpc_workqueue *workqueue = (grpc_workqueue *)closure->scheduler;
-  /* take a ref to the workqueue: otherwise it can happen that whatever events
-   * this kicks off ends up destroying the workqueue before this function
-   * completes */
-  GRPC_WORKQUEUE_REF(workqueue, "enqueue");
-  epoll_set *eps = (epoll_set *)workqueue;
-  gpr_atm last = gpr_atm_no_barrier_fetch_add(&eps->workqueue_item_count, 1);
-  closure->error_data.error = error;
-  gpr_mpscq_push(&eps->workqueue_items, &closure->next_data.atm_next);
-  if (last == 0) {
-    workqueue_maybe_wakeup(eps);
-  }
-
-  GRPC_WORKQUEUE_UNREF(exec_ctx, workqueue, "enqueue");
-  GPR_TIMER_END("workqueue.enqueue", 0);
-}
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  epoll_set *eps = (epoll_set *)workqueue;
-  return workqueue == NULL ? grpc_schedule_on_exec_ctx
-                           : &eps->workqueue_scheduler;
-}
-
 static grpc_error *epoll_set_global_init() {
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -680,8 +564,6 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure, "write");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) { return NULL; }
-
 /*******************************************************************************
  * Pollset Definitions
  */
@@ -865,32 +747,6 @@ static void pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
   gpr_mu_destroy(&pollset->mu);
 }
 
-static bool maybe_do_workqueue_work(grpc_exec_ctx *exec_ctx, epoll_set *eps) {
-  if (gpr_mu_trylock(&eps->workqueue_read_mu)) {
-    gpr_mpscq_node *n = gpr_mpscq_pop(&eps->workqueue_items);
-    gpr_mu_unlock(&eps->workqueue_read_mu);
-    if (n != NULL) {
-      if (gpr_atm_full_fetch_add(&eps->workqueue_item_count, -1) > 1) {
-        workqueue_maybe_wakeup(eps);
-      }
-      grpc_closure *c = (grpc_closure *)n;
-      grpc_error *error = c->error_data.error;
-#ifndef NDEBUG
-      c->scheduled = false;
-#endif
-      c->cb(exec_ctx, c->cb_arg, error);
-      GRPC_ERROR_UNREF(error);
-      return true;
-    } else if (gpr_atm_no_barrier_load(&eps->workqueue_item_count) > 0) {
-      /* n == NULL might mean there's work but it's not available to be popped
-       * yet - try to ensure another workqueue wakes up to check shortly if so
-       */
-      workqueue_maybe_wakeup(eps);
-    }
-  }
-  return false;
-}
-
 /* Blocking call */
 static void acquire_epoll_lease(epoll_set *eps) {
   if (g_num_threads_per_eps > 1) {
@@ -934,12 +790,7 @@ static void do_epoll_wait(grpc_exec_ctx *exec_ctx, int epoll_fd, epoll_set *eps,
 
   for (int i = 0; i < ep_rv; ++i) {
     void *data_ptr = ep_ev[i].data.ptr;
-    if (data_ptr == &eps->workqueue_wakeup_fd) {
-      append_error(error,
-                   grpc_wakeup_fd_consume_wakeup(&eps->workqueue_wakeup_fd),
-                   err_desc);
-      maybe_do_workqueue_work(exec_ctx, eps);
-    } else if (data_ptr == &epoll_set_wakeup_fd) {
+    if (data_ptr == &epoll_set_wakeup_fd) {
       gpr_atm_rel_store(&eps->is_shutdown, 1);
       gpr_log(GPR_INFO, "pollset poller: shutdown set");
     } else {
@@ -966,18 +817,13 @@ static void epoll_set_work(grpc_exec_ctx *exec_ctx, epoll_set *eps,
      epoll set. */
   epoll_fd = eps->epoll_fd;
 
-  /* If we get some workqueue work to do, it might end up completing an item on
-     the completion queue, so there's no need to poll... so we skip that and
-     redo the complete loop to verify */
-  if (!maybe_do_workqueue_work(exec_ctx, eps)) {
-    gpr_atm_no_barrier_fetch_add(&eps->poller_count, 1);
-    g_current_thread_epoll_set = eps;
+  gpr_atm_no_barrier_fetch_add(&eps->poller_count, 1);
+  g_current_thread_epoll_set = eps;
 
-    do_epoll_wait(exec_ctx, epoll_fd, eps, error);
+  do_epoll_wait(exec_ctx, epoll_fd, eps, error);
 
-    g_current_thread_epoll_set = NULL;
-    gpr_atm_no_barrier_fetch_add(&eps->poller_count, -1);
-  }
+  g_current_thread_epoll_set = NULL;
+  gpr_atm_no_barrier_fetch_add(&eps->poller_count, -1);
 
   GPR_TIMER_END("epoll_set_work", 0);
 }
@@ -1120,7 +966,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -1138,10 +983,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.h b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.h
index 9af776a52e..2ca68cc9d1 100644
--- a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.h
+++ b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_epollex_linux.c b/src/core/lib/iomgr/ev_epollex_linux.c
index b0d1a93886..38cc23b4d0 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.c
+++ b/src/core/lib/iomgr/ev_epollex_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -59,7 +44,6 @@
 #include "src/core/lib/iomgr/sys_epoll_wrapper.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
 #include "src/core/lib/support/spinlock.h"
@@ -139,17 +123,6 @@ struct grpc_fd {
      Ref/Unref by two to avoid altering the orphaned bit */
   gpr_atm refst;
 
-  /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
-  grpc_wakeup_fd workqueue_wakeup_fd;
-  grpc_closure_scheduler workqueue_scheduler;
-  /* Spinlock guarding the read end of the workqueue (must be held to pop from
-   * workqueue_items) */
-  gpr_spinlock workqueue_read_mu;
-  /* Queue of closures to be executed */
-  gpr_mpscq workqueue_items;
-  /* Count of items in workqueue_items */
-  gpr_atm workqueue_item_count;
-
   /* The fd is either closed or we relinquished control of it. In either
      cases, this indicates that the 'fd' on this structure is no longer
      valid */
@@ -172,12 +145,6 @@ struct grpc_fd {
 static void fd_global_init(void);
 static void fd_global_shutdown(void);
 
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error);
-
-static const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
-    workqueue_enqueue, workqueue_enqueue, "workqueue"};
-
 /*******************************************************************************
  * Pollset Declarations
  */
@@ -347,13 +314,6 @@ static grpc_fd *fd_create(int fd, const char *name) {
   grpc_lfev_init(&new_fd->write_closure);
   gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
 
-  GRPC_LOG_IF_ERROR("fd_create",
-                    grpc_wakeup_fd_init(&new_fd->workqueue_wakeup_fd));
-  new_fd->workqueue_scheduler.vtable = &workqueue_scheduler_vtable;
-  new_fd->workqueue_read_mu = GPR_SPINLOCK_INITIALIZER;
-  gpr_mpscq_init(&new_fd->workqueue_items);
-  gpr_atm_no_barrier_store(&new_fd->workqueue_item_count, 0);
-
   new_fd->freelist_next = NULL;
   new_fd->on_done_closure = NULL;
 
@@ -446,91 +406,6 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure, "write");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
-  REF_BY(fd, 2, "return_workqueue");
-  return (grpc_workqueue *)fd;
-}
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  if (workqueue != NULL) {
-    ref_by((grpc_fd *)workqueue, 2, file, line, reason);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {
-  if (workqueue != NULL) {
-    unref_by(exec_ctx, (grpc_fd *)workqueue, 2, file, line, reason);
-  }
-}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    ref_by((grpc_fd *)workqueue, 2);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    unref_by(exec_ctx, (grpc_fd *)workqueue, 2);
-  }
-}
-#endif
-
-static void workqueue_wakeup(grpc_fd *fd) {
-  GRPC_LOG_IF_ERROR("workqueue_enqueue",
-                    grpc_wakeup_fd_wakeup(&fd->workqueue_wakeup_fd));
-}
-
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
-  grpc_fd *fd = (grpc_fd *)(((char *)closure->scheduler) -
-                            offsetof(grpc_fd, workqueue_scheduler));
-  REF_BY(fd, 2, "workqueue_enqueue");
-  gpr_atm last = gpr_atm_no_barrier_fetch_add(&fd->workqueue_item_count, 1);
-  closure->error_data.error = error;
-  gpr_mpscq_push(&fd->workqueue_items, &closure->next_data.atm_next);
-  if (last == 0) {
-    workqueue_wakeup(fd);
-  }
-  UNREF_BY(exec_ctx, fd, 2, "workqueue_enqueue");
-}
-
-static void fd_invoke_workqueue(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  /* handle spurious wakeups */
-  if (!gpr_spinlock_trylock(&fd->workqueue_read_mu)) return;
-  gpr_mpscq_node *n = gpr_mpscq_pop(&fd->workqueue_items);
-  gpr_spinlock_unlock(&fd->workqueue_read_mu);
-  if (n != NULL) {
-    if (gpr_atm_full_fetch_add(&fd->workqueue_item_count, -1) > 1) {
-      workqueue_wakeup(fd);
-    }
-    grpc_closure *c = (grpc_closure *)n;
-    grpc_error *error = c->error_data.error;
-#ifndef NDEBUG
-    c->scheduled = false;
-#endif
-    c->cb(exec_ctx, c->cb_arg, error);
-    GRPC_ERROR_UNREF(error);
-  } else if (gpr_atm_no_barrier_load(&fd->workqueue_item_count) > 0) {
-    /* n == NULL might mean there's work but it's not available to be popped
-     * yet - try to ensure another workqueue wakes up to check shortly if so
-     */
-    workqueue_wakeup(fd);
-  }
-}
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  return &((grpc_fd *)workqueue)->workqueue_scheduler;
-}
-
 /*******************************************************************************
  * Pollable Definitions
  */
@@ -596,22 +471,7 @@ static grpc_error *pollable_add_fd(pollable *p, grpc_fd *fd) {
       .data.ptr = fd};
   if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd->fd, &ev_fd) != 0) {
     switch (errno) {
-      case EEXIST: /* if this fd is already in the epoll set, the workqueue fd
-                      must also be - just return */
-        gpr_mu_unlock(&fd->orphaned_mu);
-        return GRPC_ERROR_NONE;
-      default:
-        append_error(&error, GRPC_OS_ERROR(errno, "epoll_ctl"), err_desc);
-    }
-  }
-  struct epoll_event ev_wq = {
-      .events = (uint32_t)(EPOLLET | EPOLLIN | EPOLLEXCLUSIVE),
-      .data.ptr = (void *)(1 + (intptr_t)fd)};
-  if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd->workqueue_wakeup_fd.read_fd, &ev_wq) !=
-      0) {
-    switch (errno) {
-      case EEXIST: /* if the workqueue fd is already in the epoll set we're ok
-                      - no need to do anything special */
+      case EEXIST:
         break;
       default:
         append_error(&error, GRPC_OS_ERROR(errno, "epoll_ctl"), err_desc);
@@ -874,29 +734,21 @@ static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
       }
       append_error(&error, grpc_wakeup_fd_consume_wakeup(&p->wakeup), err_desc);
     } else {
-      grpc_fd *fd = (grpc_fd *)(((intptr_t)data_ptr) & ~(intptr_t)1);
-      bool is_workqueue = (((intptr_t)data_ptr) & 1) != 0;
+      grpc_fd *fd = (grpc_fd *)data_ptr;
       bool cancel = (events[i].events & (EPOLLERR | EPOLLHUP)) != 0;
       bool read_ev = (events[i].events & (EPOLLIN | EPOLLPRI)) != 0;
       bool write_ev = (events[i].events & EPOLLOUT) != 0;
       if (GRPC_TRACER_ON(grpc_polling_trace)) {
         gpr_log(GPR_DEBUG,
-                "PS:%p poll %p got fd %p: is_wq=%d cancel=%d read=%d "
+                "PS:%p poll %p got fd %p: cancel=%d read=%d "
                 "write=%d",
-                pollset, p, fd, is_workqueue, cancel, read_ev, write_ev);
+                pollset, p, fd, cancel, read_ev, write_ev);
       }
-      if (is_workqueue) {
-        append_error(&error,
-                     grpc_wakeup_fd_consume_wakeup(&fd->workqueue_wakeup_fd),
-                     err_desc);
-        fd_invoke_workqueue(exec_ctx, fd);
-      } else {
-        if (read_ev || cancel) {
-          fd_become_readable(exec_ctx, fd, pollset);
-        }
-        if (write_ev || cancel) {
-          fd_become_writable(exec_ctx, fd);
-        }
+      if (read_ev || cancel) {
+        fd_become_readable(exec_ctx, fd, pollset);
+      }
+      if (write_ev || cancel) {
+        fd_become_writable(exec_ctx, fd);
       }
     }
   }
@@ -1449,7 +1301,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -1467,10 +1318,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_epollex_linux.h b/src/core/lib/iomgr/ev_epollex_linux.h
index a078a7f19a..cff9b43c02 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.h
+++ b/src/core/lib/iomgr/ev_epollex_linux.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.c b/src/core/lib/iomgr/ev_epollsig_linux.c
index 2f61cd5164..cc8d9be7da 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.c
+++ b/src/core/lib/iomgr/ev_epollsig_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -59,7 +44,6 @@
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
 
@@ -177,7 +161,9 @@ static void fd_global_shutdown(void);
  * Polling island Declarations
  */
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+//#define PI_REFCOUNT_DEBUG
+
+#ifdef PI_REFCOUNT_DEBUG
 
 #define PI_ADD_REF(p, r) pi_add_ref_dbg((p), (r), __FILE__, __LINE__)
 #define PI_UNREF(exec_ctx, p, r) \
@@ -192,8 +178,6 @@ static void fd_global_shutdown(void);
 
 /* This is also used as grpc_workqueue (by directly casing it) */
 typedef struct polling_island {
-  grpc_closure_scheduler workqueue_scheduler;
-
   gpr_mu mu;
   /* Ref count. Use PI_ADD_REF() and PI_UNREF() macros to increment/decrement
      the refcount.
@@ -214,15 +198,6 @@ typedef struct polling_island {
 
   /* Number of threads currently polling on this island */
   gpr_atm poller_count;
-  /* Mutex guarding the read end of the workqueue (must be held to pop from
-   * workqueue_items) */
-  gpr_mu workqueue_read_mu;
-  /* Queue of closures to be executed */
-  gpr_mpscq workqueue_items;
-  /* Count of items in workqueue_items */
-  gpr_atm workqueue_item_count;
-  /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
-  grpc_wakeup_fd workqueue_wakeup_fd;
 
   /* The fd of the underlying epoll set */
   int epoll_fd;
@@ -297,8 +272,6 @@ static __thread polling_island *g_current_thread_polling_island;
 
 /* Forward declaration */
 static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi);
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error);
 
 #ifdef GRPC_TSAN
 /* Currently TSAN may incorrectly flag data races between epoll_ctl and
@@ -311,13 +284,10 @@ static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
 gpr_atm g_epoll_sync;
 #endif /* defined(GRPC_TSAN) */
 
-static const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
-    workqueue_enqueue, workqueue_enqueue, "workqueue"};
-
 static void pi_add_ref(polling_island *pi);
 static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi);
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+#ifdef PI_REFCOUNT_DEBUG
 static void pi_add_ref_dbg(polling_island *pi, const char *reason,
                            const char *file, int line) {
   long old_cnt = gpr_atm_acq_load(&pi->ref_count);
@@ -333,36 +303,6 @@ static void pi_unref_dbg(grpc_exec_ctx *exec_ctx, polling_island *pi,
   gpr_log(GPR_DEBUG, "Unref pi: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
           (void *)pi, old_cnt, (old_cnt - 1), reason, file, line);
 }
-
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  if (workqueue != NULL) {
-    pi_add_ref_dbg((polling_island *)workqueue, reason, file, line);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {
-  if (workqueue != NULL) {
-    pi_unref_dbg(exec_ctx, (polling_island *)workqueue, reason, file, line);
-  }
-}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    pi_add_ref((polling_island *)workqueue);
-  }
-  return workqueue;
-}
-
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {
-  if (workqueue != NULL) {
-    pi_unref(exec_ctx, (polling_island *)workqueue);
-  }
-}
 #endif
 
 static void pi_add_ref(polling_island *pi) {
@@ -526,26 +466,16 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
   *error = GRPC_ERROR_NONE;
 
   pi = gpr_malloc(sizeof(*pi));
-  pi->workqueue_scheduler.vtable = &workqueue_scheduler_vtable;
   gpr_mu_init(&pi->mu);
   pi->fd_cnt = 0;
   pi->fd_capacity = 0;
   pi->fds = NULL;
   pi->epoll_fd = -1;
 
-  gpr_mu_init(&pi->workqueue_read_mu);
-  gpr_mpscq_init(&pi->workqueue_items);
-  gpr_atm_rel_store(&pi->workqueue_item_count, 0);
-
   gpr_atm_rel_store(&pi->ref_count, 0);
   gpr_atm_rel_store(&pi->poller_count, 0);
   gpr_atm_rel_store(&pi->merged_to, (gpr_atm)NULL);
 
-  if (!append_error(error, grpc_wakeup_fd_init(&pi->workqueue_wakeup_fd),
-                    err_desc)) {
-    goto done;
-  }
-
   pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 
   if (pi->epoll_fd < 0) {
@@ -553,8 +483,6 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
     goto done;
   }
 
-  polling_island_add_wakeup_fd_locked(pi, &pi->workqueue_wakeup_fd, error);
-
   if (initial_fd != NULL) {
     polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
   }
@@ -573,11 +501,7 @@ static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi) {
   if (pi->epoll_fd >= 0) {
     close(pi->epoll_fd);
   }
-  GPR_ASSERT(gpr_atm_no_barrier_load(&pi->workqueue_item_count) == 0);
-  gpr_mu_destroy(&pi->workqueue_read_mu);
-  gpr_mpscq_destroy(&pi->workqueue_items);
   gpr_mu_destroy(&pi->mu);
-  grpc_wakeup_fd_destroy(&pi->workqueue_wakeup_fd);
   gpr_free(pi->fds);
   gpr_free(pi);
 }
@@ -722,45 +646,6 @@ static void polling_island_unlock_pair(polling_island *p, polling_island *q) {
   }
 }
 
-static void workqueue_maybe_wakeup(polling_island *pi) {
-  /* If this thread is the current poller, then it may be that it's about to
-     decrement the current poller count, so we need to look past this thread */
-  bool is_current_poller = (g_current_thread_polling_island == pi);
-  gpr_atm min_current_pollers_for_wakeup = is_current_poller ? 1 : 0;
-  gpr_atm current_pollers = gpr_atm_no_barrier_load(&pi->poller_count);
-  /* Only issue a wakeup if it's likely that some poller could come in and take
-     it right now. Note that since we do an anticipatory mpscq_pop every poll
-     loop, it's ok if we miss the wakeup here, as we'll get the work item when
-     the next poller enters anyway. */
-  if (current_pollers >= min_current_pollers_for_wakeup) {
-    GRPC_LOG_IF_ERROR("workqueue_wakeup_fd",
-                      grpc_wakeup_fd_wakeup(&pi->workqueue_wakeup_fd));
-  }
-}
-
-static void workqueue_move_items_to_parent(polling_island *q) {
-  polling_island *p = (polling_island *)gpr_atm_no_barrier_load(&q->merged_to);
-  if (p == NULL) {
-    return;
-  }
-  gpr_mu_lock(&q->workqueue_read_mu);
-  int num_added = 0;
-  while (gpr_atm_no_barrier_load(&q->workqueue_item_count) > 0) {
-    gpr_mpscq_node *n = gpr_mpscq_pop(&q->workqueue_items);
-    if (n != NULL) {
-      gpr_atm_no_barrier_fetch_add(&q->workqueue_item_count, -1);
-      gpr_atm_no_barrier_fetch_add(&p->workqueue_item_count, 1);
-      gpr_mpscq_push(&p->workqueue_items, n);
-      num_added++;
-    }
-  }
-  gpr_mu_unlock(&q->workqueue_read_mu);
-  if (num_added > 0) {
-    workqueue_maybe_wakeup(p);
-  }
-  workqueue_move_items_to_parent(p);
-}
-
 static polling_island *polling_island_merge(polling_island *p,
                                             polling_island *q,
                                             grpc_error **error) {
@@ -785,8 +670,6 @@ static polling_island *polling_island_merge(polling_island *p,
     /* Add the 'merged_to' link from p --> q */
     gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
     PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
-
-    workqueue_move_items_to_parent(p);
   }
   /* else if p == q, nothing needs to be done */
 
@@ -797,32 +680,6 @@ static polling_island *polling_island_merge(polling_island *p,
   return q;
 }
 
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                              grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
-  grpc_workqueue *workqueue = (grpc_workqueue *)closure->scheduler;
-  /* take a ref to the workqueue: otherwise it can happen that whatever events
-   * this kicks off ends up destroying the workqueue before this function
-   * completes */
-  GRPC_WORKQUEUE_REF(workqueue, "enqueue");
-  polling_island *pi = (polling_island *)workqueue;
-  gpr_atm last = gpr_atm_no_barrier_fetch_add(&pi->workqueue_item_count, 1);
-  closure->error_data.error = error;
-  gpr_mpscq_push(&pi->workqueue_items, &closure->next_data.atm_next);
-  if (last == 0) {
-    workqueue_maybe_wakeup(pi);
-  }
-  workqueue_move_items_to_parent(pi);
-  GRPC_WORKQUEUE_UNREF(exec_ctx, workqueue, "enqueue");
-  GPR_TIMER_END("workqueue.enqueue", 0);
-}
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  polling_island *pi = (polling_island *)workqueue;
-  return workqueue == NULL ? grpc_schedule_on_exec_ctx
-                           : &pi->workqueue_scheduler;
-}
-
 static grpc_error *polling_island_global_init() {
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -1047,7 +904,10 @@ static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
        unhappy. */
     PI_UNREF(exec_ctx, unref_pi, "fd_orphan");
   }
-  GRPC_LOG_IF_ERROR("fd_orphan", GRPC_ERROR_REF(error));
+  if (error != GRPC_ERROR_NONE) {
+    const char *msg = grpc_error_string(error);
+    gpr_log(GPR_DEBUG, "fd_orphan: %s", msg);
+  }
   GRPC_ERROR_UNREF(error);
 }
 
@@ -1081,14 +941,6 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
   grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure, "write");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
-  gpr_mu_lock(&fd->po.mu);
-  grpc_workqueue *workqueue =
-      GRPC_WORKQUEUE_REF((grpc_workqueue *)fd->po.pi, "fd_get_workqueue");
-  gpr_mu_unlock(&fd->po.mu);
-  return workqueue;
-}
-
 /*******************************************************************************
  * Pollset Definitions
  */
@@ -1326,44 +1178,6 @@ static void pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
   gpr_mu_destroy(&pollset->po.mu);
 }
 
-static bool maybe_do_workqueue_work(grpc_exec_ctx *exec_ctx,
-                                    polling_island *pi) {
-  if (gpr_mu_trylock(&pi->workqueue_read_mu)) {
-    gpr_mpscq_node *n = gpr_mpscq_pop(&pi->workqueue_items);
-    gpr_mu_unlock(&pi->workqueue_read_mu);
-    if (n != NULL) {
-      gpr_atm remaining =
-          gpr_atm_full_fetch_add(&pi->workqueue_item_count, -1) - 1;
-      GRPC_POLLING_TRACE(
-          "maybe_do_workqueue_work: pi: %p: got closure %p, remaining = "
-          "%" PRIdPTR,
-          pi, n, remaining);
-      if (remaining > 0) {
-        workqueue_maybe_wakeup(pi);
-      }
-      grpc_closure *c = (grpc_closure *)n;
-      grpc_error *error = c->error_data.error;
-#ifndef NDEBUG
-      c->scheduled = false;
-#endif
-      c->cb(exec_ctx, c->cb_arg, error);
-      GRPC_ERROR_UNREF(error);
-      return true;
-    } else if (gpr_atm_no_barrier_load(&pi->workqueue_item_count) > 0) {
-      /* n == NULL might mean there's work but it's not available to be popped
-       * yet - try to ensure another workqueue wakes up to check shortly if so
-       */
-      GRPC_POLLING_TRACE(
-          "maybe_do_workqueue_work: pi: %p: more to do, but not yet", pi);
-      workqueue_maybe_wakeup(pi);
-    }
-  } else {
-    GRPC_POLLING_TRACE("maybe_do_workqueue_work: pi: %p: read already locked",
-                       pi);
-  }
-  return false;
-}
-
 #define GRPC_EPOLL_MAX_EVENTS 100
 /* Note: sig_mask contains the signal mask to use *during* epoll_wait() */
 static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
@@ -1419,76 +1233,61 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
   PI_ADD_REF(pi, "ps_work");
   gpr_mu_unlock(&pollset->po.mu);
 
-  /* If we get some workqueue work to do, it might end up completing an item on
-     the completion queue, so there's no need to poll... so we skip that and
-     redo the complete loop to verify */
-  GRPC_POLLING_TRACE("pollset_work: pollset: %p, worker %p, pi %p", pollset,
-                     worker, pi);
-  if (!maybe_do_workqueue_work(exec_ctx, pi)) {
-    GRPC_POLLING_TRACE("pollset_work: begins");
-    gpr_atm_no_barrier_fetch_add(&pi->poller_count, 1);
-    g_current_thread_polling_island = pi;
-
-    GRPC_SCHEDULING_START_BLOCKING_REGION;
-    ep_rv = epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms,
-                        sig_mask);
-    GRPC_SCHEDULING_END_BLOCKING_REGION;
-    if (ep_rv < 0) {
-      if (errno != EINTR) {
-        gpr_asprintf(&err_msg,
-                     "epoll_wait() epoll fd: %d failed with error: %d (%s)",
-                     epoll_fd, errno, strerror(errno));
-        append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
-      } else {
-        /* We were interrupted. Save an interation by doing a zero timeout
-           epoll_wait to see if there are any other events of interest */
-        GRPC_POLLING_TRACE(
-            "pollset_work: pollset: %p, worker: %p received kick",
-            (void *)pollset, (void *)worker);
-        ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
-      }
+  gpr_atm_no_barrier_fetch_add(&pi->poller_count, 1);
+  g_current_thread_polling_island = pi;
+
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
+  ep_rv =
+      epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms, sig_mask);
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  if (ep_rv < 0) {
+    if (errno != EINTR) {
+      gpr_asprintf(&err_msg,
+                   "epoll_wait() epoll fd: %d failed with error: %d (%s)",
+                   epoll_fd, errno, strerror(errno));
+      append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+    } else {
+      /* We were interrupted. Save an interation by doing a zero timeout
+         epoll_wait to see if there are any other events of interest */
+      GRPC_POLLING_TRACE("pollset_work: pollset: %p, worker: %p received kick",
+                         (void *)pollset, (void *)worker);
+      ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
     }
+  }
 
 #ifdef GRPC_TSAN
-    /* See the definition of g_poll_sync for more details */
-    gpr_atm_acq_load(&g_epoll_sync);
+  /* See the definition of g_poll_sync for more details */
+  gpr_atm_acq_load(&g_epoll_sync);
 #endif /* defined(GRPC_TSAN) */
 
-    for (int i = 0; i < ep_rv; ++i) {
-      void *data_ptr = ep_ev[i].data.ptr;
-      if (data_ptr == &pi->workqueue_wakeup_fd) {
-        append_error(error,
-                     grpc_wakeup_fd_consume_wakeup(&pi->workqueue_wakeup_fd),
-                     err_desc);
-        maybe_do_workqueue_work(exec_ctx, pi);
-      } else if (data_ptr == &polling_island_wakeup_fd) {
-        GRPC_POLLING_TRACE(
-            "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
-            "%d) got merged",
-            (void *)pollset, (void *)worker, epoll_fd);
-        /* This means that our polling island is merged with a different
-           island. We do not have to do anything here since the subsequent call
-           to the function pollset_work_and_unlock() will pick up the correct
-           epoll_fd */
-      } else {
-        grpc_fd *fd = data_ptr;
-        int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP);
-        int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI);
-        int write_ev = ep_ev[i].events & EPOLLOUT;
-        if (read_ev || cancel) {
-          fd_become_readable(exec_ctx, fd, pollset);
-        }
-        if (write_ev || cancel) {
-          fd_become_writable(exec_ctx, fd);
-        }
+  for (int i = 0; i < ep_rv; ++i) {
+    void *data_ptr = ep_ev[i].data.ptr;
+    if (data_ptr == &polling_island_wakeup_fd) {
+      GRPC_POLLING_TRACE(
+          "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
+          "%d) got merged",
+          (void *)pollset, (void *)worker, epoll_fd);
+      /* This means that our polling island is merged with a different
+         island. We do not have to do anything here since the subsequent call
+         to the function pollset_work_and_unlock() will pick up the correct
+         epoll_fd */
+    } else {
+      grpc_fd *fd = data_ptr;
+      int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP);
+      int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI);
+      int write_ev = ep_ev[i].events & EPOLLOUT;
+      if (read_ev || cancel) {
+        fd_become_readable(exec_ctx, fd, pollset);
+      }
+      if (write_ev || cancel) {
+        fd_become_writable(exec_ctx, fd);
       }
     }
-
-    g_current_thread_polling_island = NULL;
-    gpr_atm_no_barrier_fetch_add(&pi->poller_count, -1);
-    GRPC_POLLING_TRACE("pollset_work: ends");
   }
 
+  g_current_thread_polling_island = NULL;
+  gpr_atm_no_barrier_fetch_add(&pi->poller_count, -1);
+
   GPR_ASSERT(pi != NULL);
 
   /* Before leaving, release the extra ref we added to the polling island. It
@@ -1879,7 +1678,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -1897,10 +1695,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.h b/src/core/lib/iomgr/ev_epollsig_linux.h
index 9e4034f2a7..88328682b3 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.h
+++ b/src/core/lib/iomgr/ev_epollsig_linux.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 3a7648ac32..6145c9ec3f 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -648,8 +633,6 @@ static void fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *watcher,
   GRPC_FD_UNREF(fd, "poll");
 }
 
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) { return NULL; }
-
 /*******************************************************************************
  * pollset_posix.c
  */
@@ -1289,30 +1272,6 @@ static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
 }
 
 /*******************************************************************************
- * workqueue stubs
- */
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  return workqueue;
-}
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  return workqueue;
-}
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {}
-#endif
-
-static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) {
-  return grpc_schedule_on_exec_ctx;
-}
-
-/*******************************************************************************
  * Condition Variable polling extensions
  */
 
@@ -1529,7 +1488,6 @@ static const grpc_event_engine_vtable vtable = {
     .fd_notify_on_read = fd_notify_on_read,
     .fd_notify_on_write = fd_notify_on_write,
     .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
 
     .pollset_init = pollset_init,
     .pollset_shutdown = pollset_shutdown,
@@ -1547,10 +1505,6 @@ static const grpc_event_engine_vtable vtable = {
     .pollset_set_add_fd = pollset_set_add_fd,
     .pollset_set_del_fd = pollset_set_del_fd,
 
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_scheduler = workqueue_scheduler,
-
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_poll_posix.h b/src/core/lib/iomgr/ev_poll_posix.h
index 2890e93ead..d444e60944 100644
--- a/src/core/lib/iomgr/ev_poll_posix.h
+++ b/src/core/lib/iomgr/ev_poll_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
- * All rights reserved.
+ * Copyright 2015-2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index c4d2f23e29..54960d1ecc 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -171,10 +156,6 @@ grpc_fd *grpc_fd_create(int fd, const char *name) {
   return g_event_engine->fd_create(fd, name);
 }
 
-grpc_workqueue *grpc_fd_get_workqueue(grpc_fd *fd) {
-  return g_event_engine->fd_get_workqueue(fd);
-}
-
 int grpc_fd_wrapped_fd(grpc_fd *fd) {
   return g_event_engine->fd_wrapped_fd(fd);
 }
@@ -276,26 +257,4 @@ void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
   g_event_engine->pollset_set_del_fd(exec_ctx, pollset_set, fd);
 }
 
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
-                                   int line, const char *reason) {
-  return g_event_engine->workqueue_ref(workqueue, file, line, reason);
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason) {
-  g_event_engine->workqueue_unref(exec_ctx, workqueue, file, line, reason);
-}
-#else
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
-  return g_event_engine->workqueue_ref(workqueue);
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
-  g_event_engine->workqueue_unref(exec_ctx, workqueue);
-}
-#endif
-
-grpc_closure_scheduler *grpc_workqueue_scheduler(grpc_workqueue *workqueue) {
-  return g_event_engine->workqueue_scheduler(workqueue);
-}
-
 #endif  // GRPC_POSIX_SOCKET
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index 80619aab5f..54c4f2ee11 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -41,7 +26,6 @@
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/iomgr/workqueue.h"
 
 extern grpc_tracer_flag grpc_polling_trace; /* Disabled by default */
 
@@ -60,7 +44,6 @@ typedef struct grpc_event_engine_vtable {
   void (*fd_notify_on_write)(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                              grpc_closure *closure);
   bool (*fd_is_shutdown)(grpc_fd *fd);
-  grpc_workqueue *(*fd_get_workqueue)(grpc_fd *fd);
   grpc_pollset *(*fd_get_read_notifier_pollset)(grpc_exec_ctx *exec_ctx,
                                                 grpc_fd *fd);
 
@@ -97,17 +80,6 @@ typedef struct grpc_event_engine_vtable {
                              grpc_pollset_set *pollset_set, grpc_fd *fd);
 
   void (*shutdown_engine)(void);
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-  grpc_workqueue *(*workqueue_ref)(grpc_workqueue *workqueue, const char *file,
-                                   int line, const char *reason);
-  void (*workqueue_unref)(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason);
-#else
-  grpc_workqueue *(*workqueue_ref)(grpc_workqueue *workqueue);
-  void (*workqueue_unref)(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue);
-#endif
-  grpc_closure_scheduler *(*workqueue_scheduler)(grpc_workqueue *workqueue);
 } grpc_event_engine_vtable;
 
 void grpc_event_engine_init(void);
@@ -121,9 +93,6 @@ const char *grpc_get_poll_strategy_name();
    This takes ownership of closing fd. */
 grpc_fd *grpc_fd_create(int fd, const char *name);
 
-/* Get a workqueue that's associated with this fd */
-grpc_workqueue *grpc_fd_get_workqueue(grpc_fd *fd);
-
 /* Return the wrapped fd, or -1 if it has been released or closed. */
 int grpc_fd_wrapped_fd(grpc_fd *fd);
 
diff --git a/src/core/lib/iomgr/ev_windows.c b/src/core/lib/iomgr/ev_windows.c
index 7bf7327823..027609c7e8 100644
--- a/src/core/lib/iomgr/ev_windows.c
+++ b/src/core/lib/iomgr/ev_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/exec_ctx.c b/src/core/lib/iomgr/exec_ctx.c
index 318bb2b713..6699be3646 100644
--- a/src/core/lib/iomgr/exec_ctx.c
+++ b/src/core/lib/iomgr/exec_ctx.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -38,7 +23,6 @@
 #include <grpc/support/thd.h>
 
 #include "src/core/lib/iomgr/combiner.h"
-#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 
 bool grpc_exec_ctx_ready_to_finish(grpc_exec_ctx *exec_ctx) {
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index 759a3ae2d5..a0d2a965d5 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/executor.c b/src/core/lib/iomgr/executor.c
index 75fd5b1c50..7621a7fe75 100644
--- a/src/core/lib/iomgr/executor.c
+++ b/src/core/lib/iomgr/executor.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -36,132 +21,172 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
+#include <grpc/support/cpu.h>
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
+#include <grpc/support/tls.h>
+#include <grpc/support/useful.h>
+
 #include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/support/spinlock.h"
+
+#define MAX_DEPTH 2
 
-typedef struct grpc_executor_data {
-  int busy;          /**< is the thread currently running? */
-  int shutting_down; /**< has \a grpc_shutdown() been invoked? */
-  int pending_join;  /**< has the thread finished but not been joined? */
-  grpc_closure_list closures; /**< collection of pending work */
-  gpr_thd_id tid; /**< thread id of the thread, only valid if \a busy or \a
-                     pending_join are true */
-  gpr_thd_options options;
+typedef struct {
   gpr_mu mu;
-} grpc_executor;
+  gpr_cv cv;
+  grpc_closure_list elems;
+  size_t depth;
+  bool shutdown;
+  gpr_thd_id id;
+} thread_state;
 
-static grpc_executor g_executor;
+static thread_state *g_thread_state;
+static size_t g_max_threads;
+static gpr_atm g_cur_threads;
+static gpr_spinlock g_adding_thread_lock = GPR_SPINLOCK_STATIC_INITIALIZER;
 
-void grpc_executor_init() {
-  memset(&g_executor, 0, sizeof(grpc_executor));
-  gpr_mu_init(&g_executor.mu);
-  g_executor.options = gpr_thd_options_default();
-  gpr_thd_options_set_joinable(&g_executor.options);
-}
+GPR_TLS_DECL(g_this_thread_state);
 
-/* thread body */
-static void closure_exec_thread_func(void *ignored) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  while (1) {
-    gpr_mu_lock(&g_executor.mu);
-    if (g_executor.shutting_down != 0) {
-      gpr_mu_unlock(&g_executor.mu);
-      break;
-    }
-    if (grpc_closure_list_empty(g_executor.closures)) {
-      /* no more work, time to die */
-      GPR_ASSERT(g_executor.busy == 1);
-      g_executor.busy = 0;
-      gpr_mu_unlock(&g_executor.mu);
-      break;
-    } else {
-      grpc_closure *c = g_executor.closures.head;
-      grpc_closure_list_init(&g_executor.closures);
-      gpr_mu_unlock(&g_executor.mu);
-      while (c != NULL) {
-        grpc_closure *next = c->next_data.next;
-        grpc_error *error = c->error_data.error;
+static void executor_thread(void *arg);
+
+static size_t run_closures(grpc_exec_ctx *exec_ctx, grpc_closure_list list) {
+  size_t n = 0;
+
+  grpc_closure *c = list.head;
+  while (c != NULL) {
+    grpc_closure *next = c->next_data.next;
+    grpc_error *error = c->error_data.error;
 #ifndef NDEBUG
-        c->scheduled = false;
+    c->scheduled = false;
 #endif
-        c->cb(&exec_ctx, c->cb_arg, error);
-        GRPC_ERROR_UNREF(error);
-        c = next;
-      }
-      grpc_exec_ctx_flush(&exec_ctx);
-    }
+    c->cb(exec_ctx, c->cb_arg, error);
+    GRPC_ERROR_UNREF(error);
+    c = next;
+    n++;
   }
-  grpc_exec_ctx_finish(&exec_ctx);
+
+  return n;
 }
 
-/* Spawn the thread if new work has arrived a no thread is up */
-static void maybe_spawn_locked() {
-  if (grpc_closure_list_empty(g_executor.closures) == 1) {
-    return;
-  }
-  if (g_executor.shutting_down == 1) {
-    return;
-  }
+bool grpc_executor_is_threaded() {
+  return gpr_atm_no_barrier_load(&g_cur_threads) > 0;
+}
 
-  if (g_executor.busy != 0) {
-    /* Thread still working. New work will be picked up by already running
-     * thread. Not spawning anything. */
-    return;
-  } else if (g_executor.pending_join != 0) {
-    /* Pickup the remains of the previous incarnations of the thread. */
-    gpr_thd_join(g_executor.tid);
-    g_executor.pending_join = 0;
+void grpc_executor_set_threading(grpc_exec_ctx *exec_ctx, bool threading) {
+  gpr_atm cur_threads = gpr_atm_no_barrier_load(&g_cur_threads);
+  if (threading) {
+    if (cur_threads > 0) return;
+    g_max_threads = GPR_MAX(1, 2 * gpr_cpu_num_cores());
+    gpr_atm_no_barrier_store(&g_cur_threads, 1);
+    gpr_tls_init(&g_this_thread_state);
+    g_thread_state = gpr_zalloc(sizeof(thread_state) * g_max_threads);
+    for (size_t i = 0; i < g_max_threads; i++) {
+      gpr_mu_init(&g_thread_state[i].mu);
+      gpr_cv_init(&g_thread_state[i].cv);
+      g_thread_state[i].elems = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT;
+    }
+
+    gpr_thd_options opt = gpr_thd_options_default();
+    gpr_thd_options_set_joinable(&opt);
+    gpr_thd_new(&g_thread_state[0].id, executor_thread, &g_thread_state[0],
+                &opt);
+  } else {
+    if (cur_threads == 0) return;
+    for (size_t i = 0; i < g_max_threads; i++) {
+      gpr_mu_lock(&g_thread_state[i].mu);
+      g_thread_state[i].shutdown = true;
+      gpr_cv_signal(&g_thread_state[i].cv);
+      gpr_mu_unlock(&g_thread_state[i].mu);
+    }
+    /* ensure no thread is adding a new thread... once this is past, then
+       no thread will try to add a new one either (since shutdown is true) */
+    gpr_spinlock_lock(&g_adding_thread_lock);
+    gpr_spinlock_unlock(&g_adding_thread_lock);
+    for (gpr_atm i = 0; i < g_cur_threads; i++) {
+      gpr_thd_join(g_thread_state[i].id);
+    }
+    gpr_atm_no_barrier_store(&g_cur_threads, 0);
+    for (size_t i = 0; i < g_max_threads; i++) {
+      gpr_mu_destroy(&g_thread_state[i].mu);
+      gpr_cv_destroy(&g_thread_state[i].cv);
+      run_closures(exec_ctx, g_thread_state[i].elems);
+    }
+    gpr_free(g_thread_state);
+    gpr_tls_destroy(&g_this_thread_state);
   }
+}
 
-  /* All previous instances of the thread should have been joined at this point.
-   * Spawn time! */
-  g_executor.busy = 1;
-  GPR_ASSERT(gpr_thd_new(&g_executor.tid, closure_exec_thread_func, NULL,
-                         &g_executor.options));
-  g_executor.pending_join = 1;
+void grpc_executor_init(grpc_exec_ctx *exec_ctx) {
+  gpr_atm_no_barrier_store(&g_cur_threads, 0);
+  grpc_executor_set_threading(exec_ctx, true);
 }
 
-static void executor_push(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
-                          grpc_error *error) {
-  gpr_mu_lock(&g_executor.mu);
-  if (g_executor.shutting_down == 0) {
-    grpc_closure_list_append(&g_executor.closures, closure, error);
-    maybe_spawn_locked();
+void grpc_executor_shutdown(grpc_exec_ctx *exec_ctx) {
+  grpc_executor_set_threading(exec_ctx, false);
+}
+
+static void executor_thread(void *arg) {
+  thread_state *ts = arg;
+  gpr_tls_set(&g_this_thread_state, (intptr_t)ts);
+
+  grpc_exec_ctx exec_ctx =
+      GRPC_EXEC_CTX_INITIALIZER(0, grpc_never_ready_to_finish, NULL);
+
+  size_t subtract_depth = 0;
+  for (;;) {
+    gpr_mu_lock(&ts->mu);
+    ts->depth -= subtract_depth;
+    while (grpc_closure_list_empty(ts->elems) && !ts->shutdown) {
+      gpr_cv_wait(&ts->cv, &ts->mu, gpr_inf_future(GPR_CLOCK_REALTIME));
+    }
+    if (ts->shutdown) {
+      gpr_mu_unlock(&ts->mu);
+      break;
+    }
+    grpc_closure_list exec = ts->elems;
+    ts->elems = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT;
+    gpr_mu_unlock(&ts->mu);
+
+    subtract_depth = run_closures(&exec_ctx, exec);
+    grpc_exec_ctx_flush(&exec_ctx);
   }
-  gpr_mu_unlock(&g_executor.mu);
+  grpc_exec_ctx_finish(&exec_ctx);
 }
 
-void grpc_executor_shutdown(grpc_exec_ctx *exec_ctx) {
-  int pending_join;
-
-  gpr_mu_lock(&g_executor.mu);
-  pending_join = g_executor.pending_join;
-  g_executor.shutting_down = 1;
-  gpr_mu_unlock(&g_executor.mu);
-  /* we can release the lock at this point despite the access to the closure
-   * list below because we aren't accepting new work */
-
-  /* Execute pending callbacks, some may be performing cleanups */
-  grpc_closure *c = g_executor.closures.head;
-  grpc_closure_list_init(&g_executor.closures);
-  while (c != NULL) {
-    grpc_closure *next = c->next_data.next;
-    grpc_error *error = c->error_data.error;
-#ifndef NDEBUG
-    c->scheduled = false;
-#endif
-    c->cb(exec_ctx, c->cb_arg, error);
-    GRPC_ERROR_UNREF(error);
-    c = next;
+static void executor_push(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
+                          grpc_error *error) {
+  size_t cur_thread_count = (size_t)gpr_atm_no_barrier_load(&g_cur_threads);
+  if (cur_thread_count == 0) {
+    grpc_closure_list_append(&exec_ctx->closure_list, closure, error);
+    return;
+  }
+  thread_state *ts = (thread_state *)gpr_tls_get(&g_this_thread_state);
+  if (ts == NULL) {
+    ts = &g_thread_state[GPR_HASH_POINTER(exec_ctx, cur_thread_count)];
   }
-  grpc_exec_ctx_flush(exec_ctx);
-  GPR_ASSERT(grpc_closure_list_empty(g_executor.closures));
-  if (pending_join) {
-    gpr_thd_join(g_executor.tid);
+  gpr_mu_lock(&ts->mu);
+  if (grpc_closure_list_empty(ts->elems)) {
+    gpr_cv_signal(&ts->cv);
+  }
+  grpc_closure_list_append(&ts->elems, closure, error);
+  ts->depth++;
+  bool try_new_thread = ts->depth > MAX_DEPTH &&
+                        cur_thread_count < g_max_threads && !ts->shutdown;
+  gpr_mu_unlock(&ts->mu);
+  if (try_new_thread && gpr_spinlock_trylock(&g_adding_thread_lock)) {
+    cur_thread_count = (size_t)gpr_atm_no_barrier_load(&g_cur_threads);
+    if (cur_thread_count < g_max_threads) {
+      gpr_atm_no_barrier_store(&g_cur_threads, cur_thread_count + 1);
+
+      gpr_thd_options opt = gpr_thd_options_default();
+      gpr_thd_options_set_joinable(&opt);
+      gpr_thd_new(&g_thread_state[cur_thread_count].id, executor_thread,
+                  &g_thread_state[cur_thread_count], &opt);
+    }
+    gpr_spinlock_unlock(&g_adding_thread_lock);
   }
-  gpr_mu_destroy(&g_executor.mu);
 }
 
 static const grpc_closure_scheduler_vtable executor_vtable = {
diff --git a/src/core/lib/iomgr/executor.h b/src/core/lib/iomgr/executor.h
index 1213016383..c3382a0a12 100644
--- a/src/core/lib/iomgr/executor.h
+++ b/src/core/lib/iomgr/executor.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -41,11 +26,18 @@
  * This mechanism is meant to outsource work (grpc_closure instances) to a
  * thread, for those cases where blocking isn't an option but there isn't a
  * non-blocking solution available. */
-void grpc_executor_init();
+void grpc_executor_init(grpc_exec_ctx *exec_ctx);
 
 extern grpc_closure_scheduler *grpc_executor_scheduler;
 
 /** Shutdown the executor, running all pending work as part of the call */
 void grpc_executor_shutdown(grpc_exec_ctx *exec_ctx);
 
+/** Is the executor multi-threaded? */
+bool grpc_executor_is_threaded();
+
+/* enable/disable threading - must be called after grpc_executor_init and before
+   grpc_executor_shutdown */
+void grpc_executor_set_threading(grpc_exec_ctx *exec_ctx, bool enable);
+
 #endif /* GRPC_CORE_LIB_IOMGR_EXECUTOR_H */
diff --git a/src/core/lib/iomgr/iocp_windows.c b/src/core/lib/iomgr/iocp_windows.c
index f0f4a6ff39..e343f8a794 100644
--- a/src/core/lib/iomgr/iocp_windows.c
+++ b/src/core/lib/iomgr/iocp_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iocp_windows.h b/src/core/lib/iomgr/iocp_windows.h
index 011fee38ff..9c89e868c5 100644
--- a/src/core/lib/iomgr/iocp_windows.h
+++ b/src/core/lib/iomgr/iocp_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iomgr.c b/src/core/lib/iomgr/iomgr.c
index 1fd41c2f88..3d19953eeb 100644
--- a/src/core/lib/iomgr/iomgr.c
+++ b/src/core/lib/iomgr/iomgr.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -44,6 +29,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/timer.h"
@@ -56,11 +42,12 @@ static gpr_cv g_rcv;
 static int g_shutdown;
 static grpc_iomgr_object g_root_object;
 
-void grpc_iomgr_init(void) {
+void grpc_iomgr_init(grpc_exec_ctx *exec_ctx) {
   g_shutdown = 0;
   gpr_mu_init(&g_mu);
   gpr_cv_init(&g_rcv);
   grpc_exec_ctx_global_init();
+  grpc_executor_init(exec_ctx);
   grpc_timer_list_init(gpr_now(GPR_CLOCK_MONOTONIC));
   g_root_object.next = g_root_object.prev = &g_root_object;
   g_root_object.name = "root";
@@ -68,7 +55,7 @@ void grpc_iomgr_init(void) {
   grpc_iomgr_platform_init();
 }
 
-void grpc_iomgr_start(void) { grpc_timer_manager_init(); }
+void grpc_iomgr_start(grpc_exec_ctx *exec_ctx) { grpc_timer_manager_init(); }
 
 static size_t count_objects(void) {
   grpc_iomgr_object *obj;
@@ -93,6 +80,7 @@ void grpc_iomgr_shutdown(grpc_exec_ctx *exec_ctx) {
 
   grpc_timer_manager_shutdown();
   grpc_iomgr_platform_flush();
+  grpc_executor_shutdown(exec_ctx);
 
   gpr_mu_lock(&g_mu);
   g_shutdown = 1;
@@ -107,7 +95,8 @@ void grpc_iomgr_shutdown(grpc_exec_ctx *exec_ctx) {
       }
       last_warning_time = gpr_now(GPR_CLOCK_REALTIME);
     }
-    if (grpc_timer_check(exec_ctx, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL)) {
+    if (grpc_timer_check(exec_ctx, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL) ==
+        GRPC_TIMERS_FIRED) {
       gpr_mu_unlock(&g_mu);
       grpc_exec_ctx_flush(exec_ctx);
       grpc_iomgr_platform_flush();
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index 6e2e023615..e3cd6ebe79 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -38,10 +23,10 @@
 #include "src/core/lib/iomgr/port.h"
 
 /** Initializes the iomgr. */
-void grpc_iomgr_init(void);
+void grpc_iomgr_init(grpc_exec_ctx *exec_ctx);
 
 /** Starts any background threads for iomgr. */
-void grpc_iomgr_start(void);
+void grpc_iomgr_start(grpc_exec_ctx *exec_ctx);
 
 /** Signals the intention to shutdown the iomgr. Expects to be able to flush
  * exec_ctx. */
diff --git a/src/core/lib/iomgr/iomgr_internal.h b/src/core/lib/iomgr/iomgr_internal.h
index 805be1f1e4..836d82515d 100644
--- a/src/core/lib/iomgr/iomgr_internal.h
+++ b/src/core/lib/iomgr/iomgr_internal.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iomgr_posix.c b/src/core/lib/iomgr/iomgr_posix.c
index f5ee0c9ee4..43f5d0406e 100644
--- a/src/core/lib/iomgr/iomgr_posix.c
+++ b/src/core/lib/iomgr/iomgr_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iomgr_posix.h b/src/core/lib/iomgr/iomgr_posix.h
index d5eade962a..f7a4af6a89 100644
--- a/src/core/lib/iomgr/iomgr_posix.h
+++ b/src/core/lib/iomgr/iomgr_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iomgr_uv.c b/src/core/lib/iomgr/iomgr_uv.c
index 96516ff167..49d1a03c32 100644
--- a/src/core/lib/iomgr/iomgr_uv.c
+++ b/src/core/lib/iomgr/iomgr_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/iomgr_windows.c b/src/core/lib/iomgr/iomgr_windows.c
index b659264ede..630370166d 100644
--- a/src/core/lib/iomgr/iomgr_windows.c
+++ b/src/core/lib/iomgr/iomgr_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/is_epollexclusive_available.c b/src/core/lib/iomgr/is_epollexclusive_available.c
index 34fcf313e5..e8a7d4d52c 100644
--- a/src/core/lib/iomgr/is_epollexclusive_available.c
+++ b/src/core/lib/iomgr/is_epollexclusive_available.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/is_epollexclusive_available.h b/src/core/lib/iomgr/is_epollexclusive_available.h
index b65b819e74..1d2e133a3b 100644
--- a/src/core/lib/iomgr/is_epollexclusive_available.h
+++ b/src/core/lib/iomgr/is_epollexclusive_available.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/load_file.c b/src/core/lib/iomgr/load_file.c
index 208f74e20c..ba77a52afc 100644
--- a/src/core/lib/iomgr/load_file.c
+++ b/src/core/lib/iomgr/load_file.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/load_file.h b/src/core/lib/iomgr/load_file.h
index 73ee8c3abf..db1ffb3d63 100644
--- a/src/core/lib/iomgr/load_file.h
+++ b/src/core/lib/iomgr/load_file.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/lockfree_event.c b/src/core/lib/iomgr/lockfree_event.c
index 722031a5da..3e96f0fa52 100644
--- a/src/core/lib/iomgr/lockfree_event.c
+++ b/src/core/lib/iomgr/lockfree_event.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/lockfree_event.h b/src/core/lib/iomgr/lockfree_event.h
index 89b3d8cf22..6a14a0f3b2 100644
--- a/src/core/lib/iomgr/lockfree_event.h
+++ b/src/core/lib/iomgr/lockfree_event.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/network_status_tracker.c b/src/core/lib/iomgr/network_status_tracker.c
index 4104bf927a..4e5c1d5408 100644
--- a/src/core/lib/iomgr/network_status_tracker.c
+++ b/src/core/lib/iomgr/network_status_tracker.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/network_status_tracker.h b/src/core/lib/iomgr/network_status_tracker.h
index 67cb645f44..c0295c1f74 100644
--- a/src/core/lib/iomgr/network_status_tracker.h
+++ b/src/core/lib/iomgr/network_status_tracker.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/polling_entity.c b/src/core/lib/iomgr/polling_entity.c
index d1686aa12f..74d8794af5 100644
--- a/src/core/lib/iomgr/polling_entity.c
+++ b/src/core/lib/iomgr/polling_entity.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/polling_entity.h b/src/core/lib/iomgr/polling_entity.h
index 740e553b2a..971fd88b42 100644
--- a/src/core/lib/iomgr/polling_entity.h
+++ b/src/core/lib/iomgr/polling_entity.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset.h b/src/core/lib/iomgr/pollset.h
index 69e20098d7..3ff878e596 100644
--- a/src/core/lib/iomgr/pollset.h
+++ b/src/core/lib/iomgr/pollset.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_set.h b/src/core/lib/iomgr/pollset_set.h
index d11801d63b..29c0f03561 100644
--- a/src/core/lib/iomgr/pollset_set.h
+++ b/src/core/lib/iomgr/pollset_set.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_set_uv.c b/src/core/lib/iomgr/pollset_set_uv.c
index 836cfee4ef..90186edbb7 100644
--- a/src/core/lib/iomgr/pollset_set_uv.c
+++ b/src/core/lib/iomgr/pollset_set_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_set_windows.c b/src/core/lib/iomgr/pollset_set_windows.c
index ae18c8a3ce..2105a47ad4 100644
--- a/src/core/lib/iomgr/pollset_set_windows.c
+++ b/src/core/lib/iomgr/pollset_set_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_set_windows.h b/src/core/lib/iomgr/pollset_set_windows.h
index 0356749b15..1173f760a0 100644
--- a/src/core/lib/iomgr/pollset_set_windows.h
+++ b/src/core/lib/iomgr/pollset_set_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_uv.c b/src/core/lib/iomgr/pollset_uv.c
index 5923da98e2..8ff647f03c 100644
--- a/src/core/lib/iomgr/pollset_uv.c
+++ b/src/core/lib/iomgr/pollset_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_uv.h b/src/core/lib/iomgr/pollset_uv.h
index 0715eb4295..566c110ca6 100644
--- a/src/core/lib/iomgr/pollset_uv.h
+++ b/src/core/lib/iomgr/pollset_uv.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_windows.c b/src/core/lib/iomgr/pollset_windows.c
index b5f454cfa9..ab1a327b46 100644
--- a/src/core/lib/iomgr/pollset_windows.c
+++ b/src/core/lib/iomgr/pollset_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/pollset_windows.h b/src/core/lib/iomgr/pollset_windows.h
index 2642013afc..71878c3d30 100644
--- a/src/core/lib/iomgr/pollset_windows.h
+++ b/src/core/lib/iomgr/pollset_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index 2a553f4114..f5d15b4850 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/resolve_address.h b/src/core/lib/iomgr/resolve_address.h
index e03d16fa4e..fe1dd78576 100644
--- a/src/core/lib/iomgr/resolve_address.h
+++ b/src/core/lib/iomgr/resolve_address.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/resolve_address_posix.c b/src/core/lib/iomgr/resolve_address_posix.c
index d0ede0f2d5..a78de66941 100644
--- a/src/core/lib/iomgr/resolve_address_posix.c
+++ b/src/core/lib/iomgr/resolve_address_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/resolve_address_uv.c b/src/core/lib/iomgr/resolve_address_uv.c
index 6b468764fc..f1ea516175 100644
--- a/src/core/lib/iomgr/resolve_address_uv.c
+++ b/src/core/lib/iomgr/resolve_address_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/resolve_address_windows.c b/src/core/lib/iomgr/resolve_address_windows.c
index 22eca1fd3b..83adfd338a 100644
--- a/src/core/lib/iomgr/resolve_address_windows.c
+++ b/src/core/lib/iomgr/resolve_address_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/resource_quota.c b/src/core/lib/iomgr/resource_quota.c
index 6b2b85cce0..7c3fb93279 100644
--- a/src/core/lib/iomgr/resource_quota.c
+++ b/src/core/lib/iomgr/resource_quota.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -581,7 +566,7 @@ static void rq_reclamation_done(grpc_exec_ctx *exec_ctx, void *rq,
 grpc_resource_quota *grpc_resource_quota_create(const char *name) {
   grpc_resource_quota *resource_quota = gpr_malloc(sizeof(*resource_quota));
   gpr_ref_init(&resource_quota->refs, 1);
-  resource_quota->combiner = grpc_combiner_create(NULL);
+  resource_quota->combiner = grpc_combiner_create();
   resource_quota->free_pool = INT64_MAX;
   resource_quota->size = INT64_MAX;
   gpr_atm_no_barrier_store(&resource_quota->last_size, GPR_ATM_MAX);
@@ -594,12 +579,11 @@ grpc_resource_quota *grpc_resource_quota_create(const char *name) {
     gpr_asprintf(&resource_quota->name, "anonymous_pool_%" PRIxPTR,
                  (intptr_t)resource_quota);
   }
-  grpc_closure_init(
-      &resource_quota->rq_step_closure, rq_step, resource_quota,
-      grpc_combiner_finally_scheduler(resource_quota->combiner, true));
+  grpc_closure_init(&resource_quota->rq_step_closure, rq_step, resource_quota,
+                    grpc_combiner_finally_scheduler(resource_quota->combiner));
   grpc_closure_init(&resource_quota->rq_reclamation_done_closure,
                     rq_reclamation_done, resource_quota,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
     resource_quota->roots[i] = NULL;
   }
@@ -704,18 +688,18 @@ grpc_resource_user *grpc_resource_user_create(
       grpc_resource_quota_ref_internal(resource_quota);
   grpc_closure_init(&resource_user->allocate_closure, &ru_allocate,
                     resource_user,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   grpc_closure_init(&resource_user->add_to_free_pool_closure,
                     &ru_add_to_free_pool, resource_user,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   grpc_closure_init(&resource_user->post_reclaimer_closure[0],
                     &ru_post_benign_reclaimer, resource_user,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   grpc_closure_init(&resource_user->post_reclaimer_closure[1],
                     &ru_post_destructive_reclaimer, resource_user,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   grpc_closure_init(&resource_user->destroy_closure, &ru_destroy, resource_user,
-                    grpc_combiner_scheduler(resource_quota->combiner, false));
+                    grpc_combiner_scheduler(resource_quota->combiner));
   gpr_mu_init(&resource_user->mu);
   gpr_atm_rel_store(&resource_user->refs, 1);
   gpr_atm_rel_store(&resource_user->shutdown, 0);
@@ -772,12 +756,12 @@ void grpc_resource_user_unref(grpc_exec_ctx *exec_ctx,
 void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
                                  grpc_resource_user *resource_user) {
   if (gpr_atm_full_fetch_add(&resource_user->shutdown, 1) == 0) {
-    grpc_closure_sched(exec_ctx,
-                       grpc_closure_create(
-                           ru_shutdown, resource_user,
-                           grpc_combiner_scheduler(
-                               resource_user->resource_quota->combiner, false)),
-                       GRPC_ERROR_NONE);
+    grpc_closure_sched(
+        exec_ctx,
+        grpc_closure_create(
+            ru_shutdown, resource_user,
+            grpc_combiner_scheduler(resource_user->resource_quota->combiner)),
+        GRPC_ERROR_NONE);
   }
 }
 
diff --git a/src/core/lib/iomgr/resource_quota.h b/src/core/lib/iomgr/resource_quota.h
index 51122dad01..d66f9ae774 100644
--- a/src/core/lib/iomgr/resource_quota.h
+++ b/src/core/lib/iomgr/resource_quota.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sockaddr.h b/src/core/lib/iomgr/sockaddr.h
index 52b504390d..206d596ccd 100644
--- a/src/core/lib/iomgr/sockaddr.h
+++ b/src/core/lib/iomgr/sockaddr.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sockaddr_posix.h b/src/core/lib/iomgr/sockaddr_posix.h
index b150de42f7..22d57ca6bb 100644
--- a/src/core/lib/iomgr/sockaddr_posix.h
+++ b/src/core/lib/iomgr/sockaddr_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sockaddr_utils.c b/src/core/lib/iomgr/sockaddr_utils.c
index a6a4cac3e2..99dc2f1c78 100644
--- a/src/core/lib/iomgr/sockaddr_utils.c
+++ b/src/core/lib/iomgr/sockaddr_utils.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sockaddr_utils.h b/src/core/lib/iomgr/sockaddr_utils.h
index be3ea2038f..7692b969f2 100644
--- a/src/core/lib/iomgr/sockaddr_utils.h
+++ b/src/core/lib/iomgr/sockaddr_utils.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sockaddr_windows.h b/src/core/lib/iomgr/sockaddr_windows.h
index 971db5b32b..cf0f6b914d 100644
--- a/src/core/lib/iomgr/sockaddr_windows.h
+++ b/src/core/lib/iomgr/sockaddr_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_factory_posix.c b/src/core/lib/iomgr/socket_factory_posix.c
index 1050a14c46..7d25bc1265 100644
--- a/src/core/lib/iomgr/socket_factory_posix.c
+++ b/src/core/lib/iomgr/socket_factory_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_factory_posix.h b/src/core/lib/iomgr/socket_factory_posix.h
index 2c63299030..a46938b06e 100644
--- a/src/core/lib/iomgr/socket_factory_posix.h
+++ b/src/core/lib/iomgr/socket_factory_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_mutator.c b/src/core/lib/iomgr/socket_mutator.c
index 34b61dcfe5..c4b9a0930b 100644
--- a/src/core/lib/iomgr/socket_mutator.c
+++ b/src/core/lib/iomgr/socket_mutator.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_mutator.h b/src/core/lib/iomgr/socket_mutator.h
index 28b1710ec4..ba956e16f0 100644
--- a/src/core/lib/iomgr/socket_mutator.h
+++ b/src/core/lib/iomgr/socket_mutator.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils.h b/src/core/lib/iomgr/socket_utils.h
index cc3ee2e30c..03fe46e5e9 100644
--- a/src/core/lib/iomgr/socket_utils.h
+++ b/src/core/lib/iomgr/socket_utils.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index bbe642d0fb..b8e2a0cdfd 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_linux.c b/src/core/lib/iomgr/socket_utils_linux.c
index bf6e9e4f55..e7b094d216 100644
--- a/src/core/lib/iomgr/socket_utils_linux.c
+++ b/src/core/lib/iomgr/socket_utils_linux.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_posix.c b/src/core/lib/iomgr/socket_utils_posix.c
index 9dea0c0cd8..dfd1ffd1e3 100644
--- a/src/core/lib/iomgr/socket_utils_posix.c
+++ b/src/core/lib/iomgr/socket_utils_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 2c2fc95ff9..eef80b439e 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_uv.c b/src/core/lib/iomgr/socket_utils_uv.c
index 741bf28969..0f7de4dfad 100644
--- a/src/core/lib/iomgr/socket_utils_uv.c
+++ b/src/core/lib/iomgr/socket_utils_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_utils_windows.c b/src/core/lib/iomgr/socket_utils_windows.c
index 5bbe8fa34c..2732c159aa 100644
--- a/src/core/lib/iomgr/socket_utils_windows.c
+++ b/src/core/lib/iomgr/socket_utils_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_windows.c b/src/core/lib/iomgr/socket_windows.c
index 2f2e02f715..f73e33db86 100644
--- a/src/core/lib/iomgr/socket_windows.c
+++ b/src/core/lib/iomgr/socket_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/socket_windows.h b/src/core/lib/iomgr/socket_windows.h
index a3875ce16c..67dc4ca53e 100644
--- a/src/core/lib/iomgr/socket_windows.h
+++ b/src/core/lib/iomgr/socket_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/sys_epoll_wrapper.h b/src/core/lib/iomgr/sys_epoll_wrapper.h
index 2f08423193..3fa5357156 100644
--- a/src/core/lib/iomgr/sys_epoll_wrapper.h
+++ b/src/core/lib/iomgr/sys_epoll_wrapper.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index bc367bdfa5..6c9e51ae84 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index 5c7da999e0..abad3c2f22 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_client_posix.h b/src/core/lib/iomgr/tcp_client_posix.h
index efc5fcd5bb..b5a3814799 100644
--- a/src/core/lib/iomgr/tcp_client_posix.h
+++ b/src/core/lib/iomgr/tcp_client_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_client_uv.c b/src/core/lib/iomgr/tcp_client_uv.c
index f0856a76d4..f4084339d6 100644
--- a/src/core/lib/iomgr/tcp_client_uv.c
+++ b/src/core/lib/iomgr/tcp_client_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index d6baca50ba..e0913cfaed 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 5d360b0b80..a2404f97c1 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -558,26 +543,15 @@ static int tcp_get_fd(grpc_endpoint *ep) {
   return tcp->fd;
 }
 
-static grpc_workqueue *tcp_get_workqueue(grpc_endpoint *ep) {
-  grpc_tcp *tcp = (grpc_tcp *)ep;
-  return grpc_fd_get_workqueue(tcp->em_fd);
-}
-
 static grpc_resource_user *tcp_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   return tcp->resource_user;
 }
 
-static const grpc_endpoint_vtable vtable = {tcp_read,
-                                            tcp_write,
-                                            tcp_get_workqueue,
-                                            tcp_add_to_pollset,
-                                            tcp_add_to_pollset_set,
-                                            tcp_shutdown,
-                                            tcp_destroy,
-                                            tcp_get_resource_user,
-                                            tcp_get_peer,
-                                            tcp_get_fd};
+static const grpc_endpoint_vtable vtable = {
+    tcp_read,     tcp_write,   tcp_add_to_pollset,    tcp_add_to_pollset_set,
+    tcp_shutdown, tcp_destroy, tcp_get_resource_user, tcp_get_peer,
+    tcp_get_fd};
 
 #define MAX_CHUNK_SIZE 32 * 1024 * 1024
 
diff --git a/src/core/lib/iomgr/tcp_posix.h b/src/core/lib/iomgr/tcp_posix.h
index 4ad60c116e..6831a4a57f 100644
--- a/src/core/lib/iomgr/tcp_posix.h
+++ b/src/core/lib/iomgr/tcp_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 437a94beff..8a126b6dee 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 08997b5e2b..7bb8392d4b 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_utils_posix.h b/src/core/lib/iomgr/tcp_server_utils_posix.h
index c15e2e1493..85dea515d9 100644
--- a/src/core/lib/iomgr/tcp_server_utils_posix.h
+++ b/src/core/lib/iomgr/tcp_server_utils_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_utils_posix_common.c b/src/core/lib/iomgr/tcp_server_utils_posix_common.c
index af2b00b4b5..dbb43186bd 100644
--- a/src/core/lib/iomgr/tcp_server_utils_posix_common.c
+++ b/src/core/lib/iomgr/tcp_server_utils_posix_common.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_utils_posix_ifaddrs.c b/src/core/lib/iomgr/tcp_server_utils_posix_ifaddrs.c
index 2078a68126..a243b69f35 100644
--- a/src/core/lib/iomgr/tcp_server_utils_posix_ifaddrs.c
+++ b/src/core/lib/iomgr/tcp_server_utils_posix_ifaddrs.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_utils_posix_noifaddrs.c b/src/core/lib/iomgr/tcp_server_utils_posix_noifaddrs.c
index d6a1a0693e..34eab20d6a 100644
--- a/src/core/lib/iomgr/tcp_server_utils_posix_noifaddrs.c
+++ b/src/core/lib/iomgr/tcp_server_utils_posix_noifaddrs.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_uv.c b/src/core/lib/iomgr/tcp_server_uv.c
index d446e5312a..632a232861 100644
--- a/src/core/lib/iomgr/tcp_server_uv.c
+++ b/src/core/lib/iomgr/tcp_server_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index 4c17f08918..e8343a94a0 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
index dc23e4f521..a37a75c8fa 100644
--- a/src/core/lib/iomgr/tcp_uv.c
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -333,15 +318,12 @@ static grpc_resource_user *uv_get_resource_user(grpc_endpoint *ep) {
   return tcp->resource_user;
 }
 
-static grpc_workqueue *uv_get_workqueue(grpc_endpoint *ep) { return NULL; }
-
 static int uv_get_fd(grpc_endpoint *ep) { return -1; }
 
 static grpc_endpoint_vtable vtable = {
-    uv_endpoint_read,  uv_endpoint_write,     uv_get_workqueue,
-    uv_add_to_pollset, uv_add_to_pollset_set, uv_endpoint_shutdown,
-    uv_destroy,        uv_get_resource_user,  uv_get_peer,
-    uv_get_fd};
+    uv_endpoint_read,      uv_endpoint_write,    uv_add_to_pollset,
+    uv_add_to_pollset_set, uv_endpoint_shutdown, uv_destroy,
+    uv_get_resource_user,  uv_get_peer,          uv_get_fd};
 
 grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
                                grpc_resource_quota *resource_quota,
diff --git a/src/core/lib/iomgr/tcp_uv.h b/src/core/lib/iomgr/tcp_uv.h
index 106bec5eca..0e67481d35 100644
--- a/src/core/lib/iomgr/tcp_uv.h
+++ b/src/core/lib/iomgr/tcp_uv.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index bdd4dd07af..dbae42e936 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -410,8 +395,6 @@ static char *win_get_peer(grpc_endpoint *ep) {
   return gpr_strdup(tcp->peer_string);
 }
 
-static grpc_workqueue *win_get_workqueue(grpc_endpoint *ep) { return NULL; }
-
 static grpc_resource_user *win_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   return tcp->resource_user;
@@ -419,16 +402,10 @@ static grpc_resource_user *win_get_resource_user(grpc_endpoint *ep) {
 
 static int win_get_fd(grpc_endpoint *ep) { return -1; }
 
-static grpc_endpoint_vtable vtable = {win_read,
-                                      win_write,
-                                      win_get_workqueue,
-                                      win_add_to_pollset,
-                                      win_add_to_pollset_set,
-                                      win_shutdown,
-                                      win_destroy,
-                                      win_get_resource_user,
-                                      win_get_peer,
-                                      win_get_fd};
+static grpc_endpoint_vtable vtable = {
+    win_read,     win_write,   win_add_to_pollset,    win_add_to_pollset_set,
+    win_shutdown, win_destroy, win_get_resource_user, win_get_peer,
+    win_get_fd};
 
 grpc_endpoint *grpc_tcp_create(grpc_exec_ctx *exec_ctx, grpc_winsocket *socket,
                                grpc_channel_args *channel_args,
diff --git a/src/core/lib/iomgr/tcp_windows.h b/src/core/lib/iomgr/tcp_windows.h
index abafdb22d2..864184ce84 100644
--- a/src/core/lib/iomgr/tcp_windows.h
+++ b/src/core/lib/iomgr/tcp_windows.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/time_averaged_stats.c b/src/core/lib/iomgr/time_averaged_stats.c
index da9cae6f28..3bddec04dd 100644
--- a/src/core/lib/iomgr/time_averaged_stats.c
+++ b/src/core/lib/iomgr/time_averaged_stats.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/time_averaged_stats.h b/src/core/lib/iomgr/time_averaged_stats.h
index 284b31f94a..8745f7fa13 100644
--- a/src/core/lib/iomgr/time_averaged_stats.h
+++ b/src/core/lib/iomgr/time_averaged_stats.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/timer.h b/src/core/lib/iomgr/timer.h
index e0338f93c7..b92b8fb8b8 100644
--- a/src/core/lib/iomgr/timer.h
+++ b/src/core/lib/iomgr/timer.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -89,6 +74,12 @@ void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer);
 
 /* iomgr internal api for dealing with timers */
 
+typedef enum {
+  GRPC_TIMERS_NOT_CHECKED,
+  GRPC_TIMERS_CHECKED_AND_EMPTY,
+  GRPC_TIMERS_FIRED,
+} grpc_timer_check_result;
+
 /* Check for timers to be run, and run them.
    Return true if timer callbacks were executed.
    If next is non-null, TRY to update *next with the next running timer
@@ -96,8 +87,8 @@ void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer);
    *next is never guaranteed to be updated on any given execution; however,
    with high probability at least one thread in the system will see an update
    at any time slice. */
-bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
-                      gpr_timespec *next);
+grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
+                                         gpr_timespec now, gpr_timespec *next);
 void grpc_timer_list_init(gpr_timespec now);
 void grpc_timer_list_shutdown(grpc_exec_ctx *exec_ctx);
 
diff --git a/src/core/lib/iomgr/timer_generic.c b/src/core/lib/iomgr/timer_generic.c
index b28340b71c..69b3cfd139 100644
--- a/src/core/lib/iomgr/timer_generic.c
+++ b/src/core/lib/iomgr/timer_generic.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -101,8 +86,10 @@ static gpr_atm saturating_add(gpr_atm a, gpr_atm b) {
   return a + b;
 }
 
-static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_atm now,
-                                   gpr_atm *next, grpc_error *error);
+static grpc_timer_check_result run_some_expired_timers(grpc_exec_ctx *exec_ctx,
+                                                       gpr_atm now,
+                                                       gpr_atm *next,
+                                                       grpc_error *error);
 
 static gpr_timespec dbl_to_ts(double d) {
   gpr_timespec ts;
@@ -421,19 +408,22 @@ static size_t pop_timers(grpc_exec_ctx *exec_ctx, shard_type *shard,
   return n;
 }
 
-static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_atm now,
-                                   gpr_atm *next, grpc_error *error) {
-  size_t n = 0;
+static grpc_timer_check_result run_some_expired_timers(grpc_exec_ctx *exec_ctx,
+                                                       gpr_atm now,
+                                                       gpr_atm *next,
+                                                       grpc_error *error) {
+  grpc_timer_check_result result = GRPC_TIMERS_NOT_CHECKED;
 
   gpr_atm min_timer = gpr_atm_no_barrier_load(&g_shared_mutables.min_timer);
   gpr_tls_set(&g_last_seen_min_timer, min_timer);
   if (now < min_timer) {
     if (next != NULL) *next = GPR_MIN(*next, min_timer);
-    return 0;
+    return GRPC_TIMERS_CHECKED_AND_EMPTY;
   }
 
   if (gpr_spinlock_trylock(&g_shared_mutables.checker_mu)) {
     gpr_mu_lock(&g_shared_mutables.mu);
+    result = GRPC_TIMERS_CHECKED_AND_EMPTY;
 
     if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
       gpr_log(GPR_DEBUG, "  .. shard[%d]->min_deadline = %" PRIdPTR,
@@ -448,14 +438,17 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_atm now,
       /* For efficiency, we pop as many available timers as we can from the
          shard.  This may violate perfect timer deadline ordering, but that
          shouldn't be a big deal because we don't make ordering guarantees. */
-      n +=
-          pop_timers(exec_ctx, g_shard_queue[0], now, &new_min_deadline, error);
+      if (pop_timers(exec_ctx, g_shard_queue[0], now, &new_min_deadline,
+                     error) > 0) {
+        result = GRPC_TIMERS_FIRED;
+      }
 
       if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-        gpr_log(GPR_DEBUG, "  .. popped --> %" PRIdPTR
-                           ", shard[%d]->min_deadline %" PRIdPTR
-                           " --> %" PRIdPTR ", now=%" PRIdPTR,
-                n, (int)(g_shard_queue[0] - g_shards),
+        gpr_log(GPR_DEBUG,
+                "  .. result --> %d"
+                ", shard[%d]->min_deadline %" PRIdPTR " --> %" PRIdPTR
+                ", now=%" PRIdPTR,
+                result, (int)(g_shard_queue[0] - g_shards),
                 g_shard_queue[0]->min_deadline, new_min_deadline, now);
       }
 
@@ -476,26 +469,15 @@ static int run_some_expired_timers(grpc_exec_ctx *exec_ctx, gpr_atm now,
                              g_shard_queue[0]->min_deadline);
     gpr_mu_unlock(&g_shared_mutables.mu);
     gpr_spinlock_unlock(&g_shared_mutables.checker_mu);
-  } else if (next != NULL) {
-    /* TODO(ctiller): this forces calling code to do an short poll, and
-       then retry the timer check (because this time through the timer list was
-       contended).
-
-       We could reduce the cost here dramatically by keeping a count of how
-       many currently active pollers got through the uncontended case above
-       successfully, and waking up other pollers IFF that count drops to zero.
-
-       Once that count is in place, this entire else branch could disappear. */
-    *next = GPR_MIN(*next, now + 1);
   }
 
   GRPC_ERROR_UNREF(error);
 
-  return (int)n;
+  return result;
 }
 
-bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
-                      gpr_timespec *next) {
+grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
+                                         gpr_timespec now, gpr_timespec *next) {
   // prelude
   GPR_ASSERT(now.clock_type == g_clock_type);
   gpr_atm now_atm = timespec_to_atm_round_down(now);
@@ -513,7 +495,7 @@ bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
               "TIMER CHECK SKIP: now_atm=%" PRIdPTR " min_timer=%" PRIdPTR,
               now_atm, min_timer);
     }
-    return 0;
+    return GRPC_TIMERS_CHECKED_AND_EMPTY;
   }
 
   grpc_error *shutdown_error =
@@ -538,7 +520,7 @@ bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
     gpr_free(next_str);
   }
   // actual code
-  bool r;
+  grpc_timer_check_result r;
   gpr_atm next_atm;
   if (next == NULL) {
     r = run_some_expired_timers(exec_ctx, now_atm, NULL, shutdown_error);
@@ -556,11 +538,10 @@ bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
       gpr_asprintf(&next_str, "%" PRId64 ".%09d [%" PRIdPTR "]", next->tv_sec,
                    next->tv_nsec, next_atm);
     }
-    gpr_log(GPR_DEBUG, "TIMER CHECK END: %d timers triggered; next=%s", r,
-            next_str);
+    gpr_log(GPR_DEBUG, "TIMER CHECK END: r=%d; next=%s", r, next_str);
     gpr_free(next_str);
   }
-  return r > 0;
+  return r;
 }
 
 #endif /* GRPC_TIMER_USE_GENERIC */
diff --git a/src/core/lib/iomgr/timer_generic.h b/src/core/lib/iomgr/timer_generic.h
index c79a431aa0..72a4ac1f10 100644
--- a/src/core/lib/iomgr/timer_generic.h
+++ b/src/core/lib/iomgr/timer_generic.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/timer_heap.c b/src/core/lib/iomgr/timer_heap.c
index 03ccfe023a..a70e3942b2 100644
--- a/src/core/lib/iomgr/timer_heap.c
+++ b/src/core/lib/iomgr/timer_heap.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/timer_heap.h b/src/core/lib/iomgr/timer_heap.h
index 576c20e09a..0d64199ab9 100644
--- a/src/core/lib/iomgr/timer_heap.h
+++ b/src/core/lib/iomgr/timer_heap.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/timer_manager.c b/src/core/lib/iomgr/timer_manager.c
index 24085093e7..520d4a3252 100644
--- a/src/core/lib/iomgr/timer_manager.c
+++ b/src/core/lib/iomgr/timer_manager.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -107,86 +92,124 @@ void grpc_timer_manager_tick() {
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
-static void timer_thread(void *unused) {
-  // this threads exec_ctx: we try to run things through to completion here
-  // since it's easy to spin up new threads
-  grpc_exec_ctx exec_ctx =
-      GRPC_EXEC_CTX_INITIALIZER(0, grpc_never_ready_to_finish, NULL);
+static void run_some_timers(grpc_exec_ctx *exec_ctx) {
+  // if there's something to execute...
+  gpr_mu_lock(&g_mu);
+  // remove a waiter from the pool, and start another thread if necessary
+  --g_waiter_count;
+  if (g_waiter_count == 0 && g_threaded) {
+    start_timer_thread_and_unlock();
+  } else {
+    // if there's no thread waiting with a timeout, kick an existing
+    // waiter
+    // so that the next deadline is not missed
+    if (!g_has_timed_waiter) {
+      if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+        gpr_log(GPR_DEBUG, "kick untimed waiter");
+      }
+      gpr_cv_signal(&g_cv_wait);
+    }
+    gpr_mu_unlock(&g_mu);
+  }
+  // without our lock, flush the exec_ctx
+  grpc_exec_ctx_flush(exec_ctx);
+  gpr_mu_lock(&g_mu);
+  // garbage collect any threads hanging out that are dead
+  gc_completed_threads();
+  // get ready to wait again
+  ++g_waiter_count;
+  gpr_mu_unlock(&g_mu);
+}
+
+// wait until 'next' (or forever if there is already a timed waiter in the pool)
+// returns true if the thread should continue executing (false if it should
+// shutdown)
+static bool wait_until(gpr_timespec next) {
+  const gpr_timespec inf_future = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  gpr_mu_lock(&g_mu);
+  // if we're not threaded anymore, leave
+  if (!g_threaded) {
+    gpr_mu_unlock(&g_mu);
+    return false;
+  }
+  // if there's no timed waiter, we should become one: that waiter waits
+  // only until the next timer should expire
+  // all other timers wait forever
+  uint64_t my_timed_waiter_generation = g_timed_waiter_generation - 1;
+  if (!g_has_timed_waiter && gpr_time_cmp(next, inf_future) != 0) {
+    g_has_timed_waiter = true;
+    // we use a generation counter to track the timed waiter so we can
+    // cancel an existing one quickly (and when it actually times out it'll
+    // figure stuff out instead of incurring a wakeup)
+    my_timed_waiter_generation = ++g_timed_waiter_generation;
+    if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+      gpr_timespec wait_time = gpr_time_sub(next, gpr_now(GPR_CLOCK_MONOTONIC));
+      gpr_log(GPR_DEBUG, "sleep for a %" PRId64 ".%09d seconds",
+              wait_time.tv_sec, wait_time.tv_nsec);
+    }
+  } else {
+    next = inf_future;
+    if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+      gpr_log(GPR_DEBUG, "sleep until kicked");
+    }
+  }
+  gpr_cv_wait(&g_cv_wait, &g_mu, next);
+  if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
+    gpr_log(GPR_DEBUG, "wait ended: was_timed:%d kicked:%d",
+            my_timed_waiter_generation == g_timed_waiter_generation, g_kicked);
+  }
+  // if this was the timed waiter, then we need to check timers, and flag
+  // that there's now no timed waiter... we'll look for a replacement if
+  // there's work to do after checking timers (code above)
+  if (my_timed_waiter_generation == g_timed_waiter_generation) {
+    g_has_timed_waiter = false;
+  }
+  // if this was a kick from the timer system, consume it (and don't stop
+  // this thread yet)
+  if (g_kicked) {
+    grpc_timer_consume_kick();
+    g_kicked = false;
+  }
+  gpr_mu_unlock(&g_mu);
+  return true;
+}
+
+static void timer_main_loop(grpc_exec_ctx *exec_ctx) {
   const gpr_timespec inf_future = gpr_inf_future(GPR_CLOCK_MONOTONIC);
   for (;;) {
     gpr_timespec next = inf_future;
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     // check timer state, updates next to the next time to run a check
-    if (grpc_timer_check(&exec_ctx, now, &next)) {
-      // if there's something to execute...
-      gpr_mu_lock(&g_mu);
-      // remove a waiter from the pool, and start another thread if necessary
-      --g_waiter_count;
-      if (g_waiter_count == 0 && g_threaded) {
-        start_timer_thread_and_unlock();
-      } else {
-        // if there's no thread waiting with a timeout, kick an existing waiter
-        // so that the next deadline is not missed
-        if (!g_has_timed_waiter) {
-          if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-            gpr_log(GPR_DEBUG, "kick untimed waiter");
-          }
-          gpr_cv_signal(&g_cv_wait);
-        }
-        gpr_mu_unlock(&g_mu);
-      }
-      // without our lock, flush the exec_ctx
-      grpc_exec_ctx_flush(&exec_ctx);
-      gpr_mu_lock(&g_mu);
-      // garbage collect any threads hanging out that are dead
-      gc_completed_threads();
-      // get ready to wait again
-      ++g_waiter_count;
-      gpr_mu_unlock(&g_mu);
-    } else {
-      gpr_mu_lock(&g_mu);
-      // if we're not threaded anymore, leave
-      if (!g_threaded) break;
-      // if there's no timed waiter, we should become one: that waiter waits
-      // only until the next timer should expire
-      // all other timers wait forever
-      uint64_t my_timed_waiter_generation = g_timed_waiter_generation - 1;
-      if (!g_has_timed_waiter) {
-        g_has_timed_waiter = true;
-        // we use a generation counter to track the timed waiter so we can
-        // cancel an existing one quickly (and when it actually times out it'll
-        // figure stuff out instead of incurring a wakeup)
-        my_timed_waiter_generation = ++g_timed_waiter_generation;
+    switch (grpc_timer_check(exec_ctx, now, &next)) {
+      case GRPC_TIMERS_FIRED:
+        run_some_timers(exec_ctx);
+        break;
+      case GRPC_TIMERS_NOT_CHECKED:
+        /* This case only happens under contention, meaning more than one timer
+           manager thread checked timers concurrently.
+
+           If that happens, we're guaranteed that some other thread has just
+           checked timers, and this will avalanche into some other thread seeing
+           empty timers and doing a timed sleep.
+
+           Consequently, we can just sleep forever here and be happy at some
+           saved wakeup cycles. */
         if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-          gpr_log(GPR_DEBUG, "sleep for a while");
+          gpr_log(GPR_DEBUG, "timers not checked: expect another thread to");
         }
-      } else {
         next = inf_future;
-        if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-          gpr_log(GPR_DEBUG, "sleep until kicked");
+      /* fall through */
+      case GRPC_TIMERS_CHECKED_AND_EMPTY:
+        if (!wait_until(next)) {
+          return;
         }
-      }
-      gpr_cv_wait(&g_cv_wait, &g_mu, next);
-      if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-        gpr_log(GPR_DEBUG, "wait ended: was_timed:%d kicked:%d",
-                my_timed_waiter_generation == g_timed_waiter_generation,
-                g_kicked);
-      }
-      // if this was the timed waiter, then we need to check timers, and flag
-      // that there's now no timed waiter... we'll look for a replacement if
-      // there's work to do after checking timers (code above)
-      if (my_timed_waiter_generation == g_timed_waiter_generation) {
-        g_has_timed_waiter = false;
-      }
-      // if this was a kick from the timer system, consume it (and don't stop
-      // this thread yet)
-      if (g_kicked) {
-        grpc_timer_consume_kick();
-        g_kicked = false;
-      }
-      gpr_mu_unlock(&g_mu);
+        break;
     }
   }
+}
+
+static void timer_thread_cleanup(void) {
+  gpr_mu_lock(&g_mu);
   // terminate the thread: drop the waiter count, thread count, and let whomever
   // stopped the threading stuff know that we're done
   --g_waiter_count;
@@ -199,12 +222,21 @@ static void timer_thread(void *unused) {
   ct->next = g_completed_threads;
   g_completed_threads = ct;
   gpr_mu_unlock(&g_mu);
-  grpc_exec_ctx_finish(&exec_ctx);
   if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
     gpr_log(GPR_DEBUG, "End timer thread");
   }
 }
 
+static void timer_thread(void *unused) {
+  // this threads exec_ctx: we try to run things through to completion here
+  // since it's easy to spin up new threads
+  grpc_exec_ctx exec_ctx =
+      GRPC_EXEC_CTX_INITIALIZER(0, grpc_never_ready_to_finish, NULL);
+  timer_main_loop(&exec_ctx);
+  grpc_exec_ctx_finish(&exec_ctx);
+  timer_thread_cleanup();
+}
+
 static void start_threads(void) {
   gpr_mu_lock(&g_mu);
   if (!g_threaded) {
diff --git a/src/core/lib/iomgr/timer_manager.h b/src/core/lib/iomgr/timer_manager.h
index 46729ccea6..0ba502928a 100644
--- a/src/core/lib/iomgr/timer_manager.h
+++ b/src/core/lib/iomgr/timer_manager.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2017, Google Inc.
- * All rights reserved.
+ * Copyright 2017 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/timer_uv.c b/src/core/lib/iomgr/timer_uv.c
index 2952e44b58..f814f0e474 100644
--- a/src/core/lib/iomgr/timer_uv.c
+++ b/src/core/lib/iomgr/timer_uv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
@@ -96,9 +81,9 @@ void grpc_timer_cancel(grpc_exec_ctx *exec_ctx, grpc_timer *timer) {
   }
 }
 
-bool grpc_timer_check(grpc_exec_ctx *exec_ctx, gpr_timespec now,
-                      gpr_timespec *next) {
-  return false;
+grpc_timer_check_result grpc_timer_check(grpc_exec_ctx *exec_ctx,
+                                         gpr_timespec now, gpr_timespec *next) {
+  return GRPC_TIMERS_NOT_CHECKED;
 }
 
 void grpc_timer_list_init(gpr_timespec now) {}
diff --git a/src/core/lib/iomgr/timer_uv.h b/src/core/lib/iomgr/timer_uv.h
index 9870cd4a5c..8a4c17c844 100644
--- a/src/core/lib/iomgr/timer_uv.h
+++ b/src/core/lib/iomgr/timer_uv.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index af70746064..200a722c7e 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/udp_server.h b/src/core/lib/iomgr/udp_server.h
index 8006037644..881468ea2c 100644
--- a/src/core/lib/iomgr/udp_server.h
+++ b/src/core/lib/iomgr/udp_server.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/unix_sockets_posix.c b/src/core/lib/iomgr/unix_sockets_posix.c
index 281865aece..0c8627c8c6 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.c
+++ b/src/core/lib/iomgr/unix_sockets_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 #include "src/core/lib/iomgr/port.h"
diff --git a/src/core/lib/iomgr/unix_sockets_posix.h b/src/core/lib/iomgr/unix_sockets_posix.h
index 21afd3aa15..25b64b3eec 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.h
+++ b/src/core/lib/iomgr/unix_sockets_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/unix_sockets_posix_noop.c b/src/core/lib/iomgr/unix_sockets_posix_noop.c
index b9602cbf8b..e46b1c003d 100644
--- a/src/core/lib/iomgr/unix_sockets_posix_noop.c
+++ b/src/core/lib/iomgr/unix_sockets_posix_noop.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.c b/src/core/lib/iomgr/wakeup_fd_cv.c
index da4c2870cd..075a0b6426 100644
--- a/src/core/lib/iomgr/wakeup_fd_cv.c
+++ b/src/core/lib/iomgr/wakeup_fd_cv.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.h b/src/core/lib/iomgr/wakeup_fd_cv.h
index ac16be1750..c5dcdc9746 100644
--- a/src/core/lib/iomgr/wakeup_fd_cv.h
+++ b/src/core/lib/iomgr/wakeup_fd_cv.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2016, Google Inc.
- * All rights reserved.
+ * Copyright 2016 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_eventfd.c b/src/core/lib/iomgr/wakeup_fd_eventfd.c
index 373e21d3e1..81cb7ee280 100644
--- a/src/core/lib/iomgr/wakeup_fd_eventfd.c
+++ b/src/core/lib/iomgr/wakeup_fd_eventfd.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_nospecial.c b/src/core/lib/iomgr/wakeup_fd_nospecial.c
index 611bced029..4c20b8c1b7 100644
--- a/src/core/lib/iomgr/wakeup_fd_nospecial.c
+++ b/src/core/lib/iomgr/wakeup_fd_nospecial.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index e186d63683..4189488f8a 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.h b/src/core/lib/iomgr/wakeup_fd_pipe.h
index 8972efc270..f860406bda 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.h
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.c b/src/core/lib/iomgr/wakeup_fd_posix.c
index 85526402bd..25daa7d3fb 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.c
+++ b/src/core/lib/iomgr/wakeup_fd_posix.c
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.h b/src/core/lib/iomgr/wakeup_fd_posix.h
index c8dd242c75..a9584d0d48 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.h
+++ b/src/core/lib/iomgr/wakeup_fd_posix.h
@@ -1,33 +1,18 @@
 /*
  *
- * Copyright 2015, Google Inc.
- * All rights reserved.
+ * Copyright 2015 gRPC authors.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  *
  */
 
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
deleted file mode 100644
index 371b0f55dc..0000000000
--- a/src/core/lib/iomgr/workqueue.h
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_IOMGR_WORKQUEUE_H
-#define GRPC_CORE_LIB_IOMGR_WORKQUEUE_H
-
-#include "src/core/lib/iomgr/closure.h"
-#include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/iomgr/iomgr.h"
-#include "src/core/lib/iomgr/pollset.h"
-#include "src/core/lib/iomgr/pollset_set.h"
-#include "src/core/lib/iomgr/port.h"
-
-#ifdef GPR_WINDOWS
-#include "src/core/lib/iomgr/workqueue_windows.h"
-#endif
-
-/* grpc_workqueue is forward declared in exec_ctx.h */
-
-/* Reference counting functions. Use the macro's always
-   (GRPC_WORKQUEUE_{REF,UNREF}).
-
-   Pass in a descriptive reason string for reffing/unreffing as the last
-   argument to each macro. When GRPC_WORKQUEUE_REFCOUNT_DEBUG is defined, that
-   string will be printed alongside the refcount. When it is not defined, the
-   string will be discarded at compilation time. */
-
-/*#define GRPC_WORKQUEUE_REFCOUNT_DEBUG*/
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-#define GRPC_WORKQUEUE_REF(p, r) \
-  grpc_workqueue_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_WORKQUEUE_UNREF(exec_ctx, p, r) \
-  grpc_workqueue_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
-                                   int line, const char *reason);
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason);
-#else
-#define GRPC_WORKQUEUE_REF(p, r) grpc_workqueue_ref((p))
-#define GRPC_WORKQUEUE_UNREF(cl, p, r) grpc_workqueue_unref((cl), (p))
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue);
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue);
-#endif
-
-/** Fetch the workqueue closure scheduler. Items added to a work queue will be
-    started in approximately the order they were enqueued, on some thread that
-    may or may not be the current thread. Successive closures enqueued onto a
-    workqueue MAY be executed concurrently.
-
-    It is generally more expensive to add a closure to a workqueue than to the
-    execution context, both in terms of CPU work and in execution latency.
-
-    Use work queues when it's important that other threads be given a chance to
-    tackle some workload. */
-grpc_closure_scheduler *grpc_workqueue_scheduler(grpc_workqueue *workqueue);
-
-#endif /* GRPC_CORE_LIB_IOMGR_WORKQUEUE_H */
diff --git a/src/core/lib/iomgr/workqueue_uv.c b/src/core/lib/iomgr/workqueue_uv.c
deleted file mode 100644
index 4d61b40912..0000000000
--- a/src/core/lib/iomgr/workqueue_uv.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/lib/iomgr/port.h"
-
-#ifdef GRPC_UV
-
-#include "src/core/lib/iomgr/workqueue.h"
-
-// Minimal implementation of grpc_workqueue for libuv
-// Works by directly enqueuing workqueue items onto the current execution
-// context, which is at least correct, if not performant or in the spirit of
-// workqueues.
-
-void grpc_workqueue_flush(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
-                                   int line, const char *reason) {
-  return workqueue;
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason) {}
-#else
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
-  return workqueue;
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
-#endif
-
-grpc_closure_scheduler *grpc_workqueue_scheduler(grpc_workqueue *workqueue) {
-  return grpc_schedule_on_exec_ctx;
-}
-
-#endif /* GPR_UV */
diff --git a/src/core/lib/iomgr/workqueue_uv.h b/src/core/lib/iomgr/workqueue_uv.h
deleted file mode 100644
index be3f8e4d93..0000000000
--- a/src/core/lib/iomgr/workqueue_uv.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H
-#define GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H
-
-#endif /* GRPC_CORE_LIB_IOMGR_WORKQUEUE_UV_H */
diff --git a/src/core/lib/iomgr/workqueue_windows.c b/src/core/lib/iomgr/workqueue_windows.c
deleted file mode 100644
index 234b47cdf5..0000000000
--- a/src/core/lib/iomgr/workqueue_windows.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include <grpc/support/port_platform.h>
-
-#ifdef GPR_WINDOWS
-
-#include "src/core/lib/iomgr/workqueue.h"
-
-// Minimal implementation of grpc_workqueue for Windows
-// Works by directly enqueuing workqueue items onto the current execution
-// context, which is at least correct, if not performant or in the spirit of
-// workqueues.
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
-                                   int line, const char *reason) {
-  return workqueue;
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason) {}
-#else
-grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
-  return workqueue;
-}
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
-#endif
-
-grpc_closure_scheduler *grpc_workqueue_scheduler(grpc_workqueue *workqueue) {
-  return grpc_schedule_on_exec_ctx;
-}
-
-#endif /* GPR_WINDOWS */
diff --git a/src/core/lib/iomgr/workqueue_windows.h b/src/core/lib/iomgr/workqueue_windows.h
deleted file mode 100644
index e5d59130bb..0000000000
--- a/src/core/lib/iomgr/workqueue_windows.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_IOMGR_WORKQUEUE_WINDOWS_H
-#define GRPC_CORE_LIB_IOMGR_WORKQUEUE_WINDOWS_H
-
-#endif /* GRPC_CORE_LIB_IOMGR_WORKQUEUE_WINDOWS_H */