Merge branch 'master' of https://github.com/grpc/grpc into gpr_malloc_is_all

78 files changed, 2395 insertions, 2306 deletions

diff --git a/src/core/lib/iomgr/closure.c b/src/core/lib/iomgr/closure.c
index 724ebc284a..d6f073fc9d 100644
--- a/src/core/lib/iomgr/closure.c
+++ b/src/core/lib/iomgr/closure.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 2597cf1706..8652b53a8b 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/endpoint.c b/src/core/lib/iomgr/endpoint.c
index 576b5a6e5c..1ab3733d38 100644
--- a/src/core/lib/iomgr/endpoint.c
+++ b/src/core/lib/iomgr/endpoint.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index 918e705fbd..3877ceb1e2 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/endpoint_pair.h b/src/core/lib/iomgr/endpoint_pair.h
index bef8bb3518..5cd78051bd 100644
--- a/src/core/lib/iomgr/endpoint_pair.h
+++ b/src/core/lib/iomgr/endpoint_pair.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/endpoint_pair_windows.c b/src/core/lib/iomgr/endpoint_pair_windows.c
index cba18db81f..582704e267 100644
--- a/src/core/lib/iomgr/endpoint_pair_windows.c
+++ b/src/core/lib/iomgr/endpoint_pair_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
new file mode 100644
index 0000000000..dba335490b
--- /dev/null
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
@@ -0,0 +1,1936 @@
+/*
+ *
+ * Copyright 2015-2016, 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.
+ *
+ */
+
+/* This file will be removed shortly: it's here to keep refactoring
+ * steps simple and auditable.
+ * It's the combination of the old files:
+ *  - fd_posix.{h,c}
+ *  - pollset_posix.{h,c}
+ *  - pullset_multipoller_with_{poll,epoll}.{h,c}
+ * The new version will be split into:
+ *  - ev_poll_posix.{h,c}
+ *  - ev_epoll_posix.{h,c}
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <poll.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/tls.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/wakeup_fd_posix.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/block_annotate.h"
+
+/*******************************************************************************
+ * FD declarations
+ */
+
+typedef struct grpc_fd_watcher {
+  struct grpc_fd_watcher *next;
+  struct grpc_fd_watcher *prev;
+  grpc_pollset *pollset;
+  grpc_pollset_worker *worker;
+  grpc_fd *fd;
+} grpc_fd_watcher;
+
+struct grpc_fd {
+  int fd;
+  /* refst format:
+     bit0:   1=active/0=orphaned
+     bit1-n: refcount
+     meaning that mostly we ref by two to avoid altering the orphaned bit,
+     and just unref by 1 when we're ready to flag the object as orphaned */
+  gpr_atm refst;
+
+  gpr_mu mu;
+  int shutdown;
+  int closed;
+  int released;
+
+  /* The watcher list.
+
+     The following watcher related fields are protected by watcher_mu.
+
+     An fd_watcher is an ephemeral object created when an fd wants to
+     begin polling, and destroyed after the poll.
+
+     It denotes the fd's interest in whether to read poll or write poll
+     or both or neither on this fd.
+
+     If a watcher is asked to poll for reads or writes, the read_watcher
+     or write_watcher fields are set respectively. A watcher may be asked
+     to poll for both, in which case both fields will be set.
+
+     read_watcher and write_watcher may be NULL if no watcher has been
+     asked to poll for reads or writes.
+
+     If an fd_watcher is not asked to poll for reads or writes, it's added
+     to a linked list of inactive watchers, rooted at inactive_watcher_root.
+     If at a later time there becomes need of a poller to poll, one of
+     the inactive pollers may be kicked out of their poll loops to take
+     that responsibility. */
+  grpc_fd_watcher inactive_watcher_root;
+  grpc_fd_watcher *read_watcher;
+  grpc_fd_watcher *write_watcher;
+
+  grpc_closure *read_closure;
+  grpc_closure *write_closure;
+
+  struct grpc_fd *freelist_next;
+
+  grpc_closure *on_done_closure;
+
+  grpc_iomgr_object iomgr_object;
+};
+
+/* Begin polling on an fd.
+   Registers that the given pollset is interested in this fd - so that if read
+   or writability interest changes, the pollset can be kicked to pick up that
+   new interest.
+   Return value is:
+     (fd_needs_read? read_mask : 0) | (fd_needs_write? write_mask : 0)
+   i.e. a combination of read_mask and write_mask determined by the fd's current
+   interest in said events.
+   Polling strategies that do not need to alter their behavior depending on the
+   fd's current interest (such as epoll) do not need to call this function.
+   MUST NOT be called with a pollset lock taken */
+static uint32_t fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
+                              grpc_pollset_worker *worker, uint32_t read_mask,
+                              uint32_t write_mask, grpc_fd_watcher *rec);
+/* Complete polling previously started with fd_begin_poll
+   MUST NOT be called with a pollset lock taken
+   if got_read or got_write are 1, also does the become_{readable,writable} as
+   appropriate. */
+static void fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *rec,
+                        int got_read, int got_write);
+
+/* Return 1 if this fd is orphaned, 0 otherwise */
+static bool fd_is_orphaned(grpc_fd *fd);
+
+/* Reference counting for fds */
+/*#define GRPC_FD_REF_COUNT_DEBUG*/
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void fd_ref(grpc_fd *fd, const char *reason, const char *file, int line);
+static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
+                     int line);
+#define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__)
+#define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__)
+#else
+static void fd_ref(grpc_fd *fd);
+static void fd_unref(grpc_fd *fd);
+#define GRPC_FD_REF(fd, reason) fd_ref(fd)
+#define GRPC_FD_UNREF(fd, reason) fd_unref(fd)
+#endif
+
+static void fd_global_init(void);
+static void fd_global_shutdown(void);
+
+#define CLOSURE_NOT_READY ((grpc_closure *)0)
+#define CLOSURE_READY ((grpc_closure *)1)
+
+/*******************************************************************************
+ * pollset declarations
+ */
+
+typedef struct grpc_pollset_vtable grpc_pollset_vtable;
+
+typedef struct grpc_cached_wakeup_fd {
+  grpc_wakeup_fd fd;
+  struct grpc_cached_wakeup_fd *next;
+} grpc_cached_wakeup_fd;
+
+struct grpc_pollset_worker {
+  grpc_cached_wakeup_fd *wakeup_fd;
+  int reevaluate_polling_on_wakeup;
+  int kicked_specifically;
+  struct grpc_pollset_worker *next;
+  struct grpc_pollset_worker *prev;
+};
+
+struct grpc_pollset {
+  /* pollsets under posix can mutate representation as fds are added and
+     removed.
+     For example, we may choose a poll() based implementation on linux for
+     few fds, and an epoll() based implementation for many fds */
+  const grpc_pollset_vtable *vtable;
+  gpr_mu mu;
+  grpc_pollset_worker root_worker;
+  int in_flight_cbs;
+  int shutting_down;
+  int called_shutdown;
+  int kicked_without_pollers;
+  grpc_closure *shutdown_done;
+  grpc_closure_list idle_jobs;
+  union {
+    int fd;
+    void *ptr;
+  } data;
+  /* Local cache of eventfds for workers */
+  grpc_cached_wakeup_fd *local_wakeup_cache;
+};
+
+struct grpc_pollset_vtable {
+  void (*add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                 struct grpc_fd *fd, int and_unlock_pollset);
+  void (*maybe_work_and_unlock)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                                grpc_pollset_worker *worker,
+                                gpr_timespec deadline, gpr_timespec now);
+  void (*finish_shutdown)(grpc_pollset *pollset);
+  void (*destroy)(grpc_pollset *pollset);
+};
+
+/* Add an fd to a pollset */
+static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           struct grpc_fd *fd);
+
+static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
+                               grpc_pollset_set *pollset_set, grpc_fd *fd);
+
+/* Convert a timespec to milliseconds:
+   - very small or negative poll times are clamped to zero to do a
+     non-blocking poll (which becomes spin polling)
+   - other small values are rounded up to one millisecond
+   - longer than a millisecond polls are rounded up to the next nearest
+     millisecond to avoid spinning
+   - infinite timeouts are converted to -1 */
+static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
+                                           gpr_timespec now);
+
+/* Allow kick to wakeup the currently polling worker */
+#define GRPC_POLLSET_CAN_KICK_SELF 1
+/* Force the wakee to repoll when awoken */
+#define GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP 2
+/* As per pollset_kick, with an extended set of flags (defined above)
+   -- mostly for fd_posix's use. */
+static void pollset_kick_ext(grpc_pollset *p,
+                             grpc_pollset_worker *specific_worker,
+                             uint32_t flags);
+
+/* turn a pollset into a multipoller: platform specific */
+typedef void (*platform_become_multipoller_type)(grpc_exec_ctx *exec_ctx,
+                                                 grpc_pollset *pollset,
+                                                 struct grpc_fd **fds,
+                                                 size_t fd_count);
+static platform_become_multipoller_type platform_become_multipoller;
+
+/* Return 1 if the pollset has active threads in pollset_work (pollset must
+ * be locked) */
+static int pollset_has_workers(grpc_pollset *pollset);
+
+static void remove_fd_from_all_epoll_sets(int fd);
+
+/*******************************************************************************
+ * pollset_set definitions
+ */
+
+struct grpc_pollset_set {
+  gpr_mu mu;
+
+  size_t pollset_count;
+  size_t pollset_capacity;
+  grpc_pollset **pollsets;
+
+  size_t pollset_set_count;
+  size_t pollset_set_capacity;
+  struct grpc_pollset_set **pollset_sets;
+
+  size_t fd_count;
+  size_t fd_capacity;
+  grpc_fd **fds;
+};
+
+/*******************************************************************************
+ * fd_posix.c
+ */
+
+/* We need to keep a freelist not because of any concerns of malloc performance
+ * but instead so that implementations with multiple threads in (for example)
+ * epoll_wait deal with the race between pollset removal and incoming poll
+ * notifications.
+ *
+ * The problem is that the poller ultimately holds a reference to this
+ * object, so it is very difficult to know when is safe to free it, at least
+ * without some expensive synchronization.
+ *
+ * If we keep the object freelisted, in the worst case losing this race just
+ * becomes a spurious read notification on a reused fd.
+ */
+/* TODO(klempner): We could use some form of polling generation count to know
+ * when these are safe to free. */
+/* TODO(klempner): Consider disabling freelisting if we don't have multiple
+ * threads in poll on the same fd */
+/* TODO(klempner): Batch these allocations to reduce fragmentation */
+static grpc_fd *fd_freelist = NULL;
+static gpr_mu fd_freelist_mu;
+
+static void freelist_fd(grpc_fd *fd) {
+  gpr_mu_lock(&fd_freelist_mu);
+  fd->freelist_next = fd_freelist;
+  fd_freelist = fd;
+  grpc_iomgr_unregister_object(&fd->iomgr_object);
+  gpr_mu_unlock(&fd_freelist_mu);
+}
+
+static grpc_fd *alloc_fd(int fd) {
+  grpc_fd *r = NULL;
+  gpr_mu_lock(&fd_freelist_mu);
+  if (fd_freelist != NULL) {
+    r = fd_freelist;
+    fd_freelist = fd_freelist->freelist_next;
+  }
+  gpr_mu_unlock(&fd_freelist_mu);
+  if (r == NULL) {
+    r = gpr_malloc(sizeof(grpc_fd));
+    gpr_mu_init(&r->mu);
+  }
+
+  gpr_mu_lock(&r->mu);
+  gpr_atm_rel_store(&r->refst, 1);
+  r->shutdown = 0;
+  r->read_closure = CLOSURE_NOT_READY;
+  r->write_closure = CLOSURE_NOT_READY;
+  r->fd = fd;
+  r->inactive_watcher_root.next = r->inactive_watcher_root.prev =
+      &r->inactive_watcher_root;
+  r->freelist_next = NULL;
+  r->read_watcher = r->write_watcher = NULL;
+  r->on_done_closure = NULL;
+  r->closed = 0;
+  r->released = 0;
+  gpr_mu_unlock(&r->mu);
+  return r;
+}
+
+static void destroy(grpc_fd *fd) {
+  gpr_mu_destroy(&fd->mu);
+  gpr_free(fd);
+}
+
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+#define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__)
+#define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
+static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file,
+                   int line) {
+  gpr_log(GPR_DEBUG, "FD %d %p   ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
+          gpr_atm_no_barrier_load(&fd->refst),
+          gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
+#else
+#define REF_BY(fd, n, reason) ref_by(fd, n)
+#define UNREF_BY(fd, n, reason) unref_by(fd, n)
+static void ref_by(grpc_fd *fd, int n) {
+#endif
+  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0);
+}
+
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file,
+                     int line) {
+  gpr_atm old;
+  gpr_log(GPR_DEBUG, "FD %d %p unref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
+          gpr_atm_no_barrier_load(&fd->refst),
+          gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line);
+#else
+static void unref_by(grpc_fd *fd, int n) {
+  gpr_atm old;
+#endif
+  old = gpr_atm_full_fetch_add(&fd->refst, -n);
+  if (old == n) {
+    freelist_fd(fd);
+  } else {
+    GPR_ASSERT(old > n);
+  }
+}
+
+static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); }
+
+static void fd_global_shutdown(void) {
+  gpr_mu_lock(&fd_freelist_mu);
+  gpr_mu_unlock(&fd_freelist_mu);
+  while (fd_freelist != NULL) {
+    grpc_fd *fd = fd_freelist;
+    fd_freelist = fd_freelist->freelist_next;
+    destroy(fd);
+  }
+  gpr_mu_destroy(&fd_freelist_mu);
+}
+
+static grpc_fd *fd_create(int fd, const char *name) {
+  grpc_fd *r = alloc_fd(fd);
+  char *name2;
+  gpr_asprintf(&name2, "%s fd=%d", name, fd);
+  grpc_iomgr_register_object(&r->iomgr_object, name2);
+  gpr_free(name2);
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+  gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, r, name);
+#endif
+  return r;
+}
+
+static bool fd_is_orphaned(grpc_fd *fd) {
+  return (gpr_atm_acq_load(&fd->refst) & 1) == 0;
+}
+
+static void pollset_kick_locked(grpc_fd_watcher *watcher) {
+  gpr_mu_lock(&watcher->pollset->mu);
+  GPR_ASSERT(watcher->worker);
+  pollset_kick_ext(watcher->pollset, watcher->worker,
+                   GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP);
+  gpr_mu_unlock(&watcher->pollset->mu);
+}
+
+static void maybe_wake_one_watcher_locked(grpc_fd *fd) {
+  if (fd->inactive_watcher_root.next != &fd->inactive_watcher_root) {
+    pollset_kick_locked(fd->inactive_watcher_root.next);
+  } else if (fd->read_watcher) {
+    pollset_kick_locked(fd->read_watcher);
+  } else if (fd->write_watcher) {
+    pollset_kick_locked(fd->write_watcher);
+  }
+}
+
+static void wake_all_watchers_locked(grpc_fd *fd) {
+  grpc_fd_watcher *watcher;
+  for (watcher = fd->inactive_watcher_root.next;
+       watcher != &fd->inactive_watcher_root; watcher = watcher->next) {
+    pollset_kick_locked(watcher);
+  }
+  if (fd->read_watcher) {
+    pollset_kick_locked(fd->read_watcher);
+  }
+  if (fd->write_watcher && fd->write_watcher != fd->read_watcher) {
+    pollset_kick_locked(fd->write_watcher);
+  }
+}
+
+static int has_watchers(grpc_fd *fd) {
+  return fd->read_watcher != NULL || fd->write_watcher != NULL ||
+         fd->inactive_watcher_root.next != &fd->inactive_watcher_root;
+}
+
+static void close_fd_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+  fd->closed = 1;
+  if (!fd->released) {
+    close(fd->fd);
+  } else {
+    remove_fd_from_all_epoll_sets(fd->fd);
+  }
+  grpc_exec_ctx_enqueue(exec_ctx, fd->on_done_closure, true, NULL);
+}
+
+static int fd_wrapped_fd(grpc_fd *fd) {
+  if (fd->released || fd->closed) {
+    return -1;
+  } else {
+    return fd->fd;
+  }
+}
+
+static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                      grpc_closure *on_done, int *release_fd,
+                      const char *reason) {
+  fd->on_done_closure = on_done;
+  fd->released = release_fd != NULL;
+  if (!fd->released) {
+    shutdown(fd->fd, SHUT_RDWR);
+  } else {
+    *release_fd = fd->fd;
+  }
+  gpr_mu_lock(&fd->mu);
+  REF_BY(fd, 1, reason); /* remove active status, but keep referenced */
+  if (!has_watchers(fd)) {
+    close_fd_locked(exec_ctx, fd);
+  } else {
+    wake_all_watchers_locked(fd);
+  }
+  gpr_mu_unlock(&fd->mu);
+  UNREF_BY(fd, 2, reason); /* drop the reference */
+}
+
+/* increment refcount by two to avoid changing the orphan bit */
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void fd_ref(grpc_fd *fd, const char *reason, const char *file,
+                   int line) {
+  ref_by(fd, 2, reason, file, line);
+}
+
+static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
+                     int line) {
+  unref_by(fd, 2, reason, file, line);
+}
+#else
+static void fd_ref(grpc_fd *fd) { ref_by(fd, 2); }
+
+static void fd_unref(grpc_fd *fd) { unref_by(fd, 2); }
+#endif
+
+static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                             grpc_closure **st, grpc_closure *closure) {
+  if (*st == CLOSURE_NOT_READY) {
+    /* not ready ==> switch to a waiting state by setting the closure */
+    *st = closure;
+  } else if (*st == CLOSURE_READY) {
+    /* already ready ==> queue the closure to run immediately */
+    *st = CLOSURE_NOT_READY;
+    grpc_exec_ctx_enqueue(exec_ctx, closure, !fd->shutdown, NULL);
+    maybe_wake_one_watcher_locked(fd);
+  } else {
+    /* upcallptr was set to a different closure.  This is an error! */
+    gpr_log(GPR_ERROR,
+            "User called a notify_on function with a previous callback still "
+            "pending");
+    abort();
+  }
+}
+
+/* returns 1 if state becomes not ready */
+static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                            grpc_closure **st) {
+  if (*st == CLOSURE_READY) {
+    /* duplicate ready ==> ignore */
+    return 0;
+  } else if (*st == CLOSURE_NOT_READY) {
+    /* not ready, and not waiting ==> flag ready */
+    *st = CLOSURE_READY;
+    return 0;
+  } else {
+    /* waiting ==> queue closure */
+    grpc_exec_ctx_enqueue(exec_ctx, *st, !fd->shutdown, NULL);
+    *st = CLOSURE_NOT_READY;
+    return 1;
+  }
+}
+
+static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+  gpr_mu_lock(&fd->mu);
+  GPR_ASSERT(!fd->shutdown);
+  fd->shutdown = 1;
+  set_ready_locked(exec_ctx, fd, &fd->read_closure);
+  set_ready_locked(exec_ctx, fd, &fd->write_closure);
+  gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                              grpc_closure *closure) {
+  gpr_mu_lock(&fd->mu);
+  notify_on_locked(exec_ctx, fd, &fd->read_closure, closure);
+  gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                               grpc_closure *closure) {
+  gpr_mu_lock(&fd->mu);
+  notify_on_locked(exec_ctx, fd, &fd->write_closure, closure);
+  gpr_mu_unlock(&fd->mu);
+}
+
+static uint32_t fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
+                              grpc_pollset_worker *worker, uint32_t read_mask,
+                              uint32_t write_mask, grpc_fd_watcher *watcher) {
+  uint32_t mask = 0;
+  grpc_closure *cur;
+  int requested;
+  /* keep track of pollers that have requested our events, in case they change
+   */
+  GRPC_FD_REF(fd, "poll");
+
+  gpr_mu_lock(&fd->mu);
+
+  /* if we are shutdown, then don't add to the watcher set */
+  if (fd->shutdown) {
+    watcher->fd = NULL;
+    watcher->pollset = NULL;
+    watcher->worker = NULL;
+    gpr_mu_unlock(&fd->mu);
+    GRPC_FD_UNREF(fd, "poll");
+    return 0;
+  }
+
+  /* if there is nobody polling for read, but we need to, then start doing so */
+  cur = fd->read_closure;
+  requested = cur != CLOSURE_READY;
+  if (read_mask && fd->read_watcher == NULL && requested) {
+    fd->read_watcher = watcher;
+    mask |= read_mask;
+  }
+  /* if there is nobody polling for write, but we need to, then start doing so
+   */
+  cur = fd->write_closure;
+  requested = cur != CLOSURE_READY;
+  if (write_mask && fd->write_watcher == NULL && requested) {
+    fd->write_watcher = watcher;
+    mask |= write_mask;
+  }
+  /* if not polling, remember this watcher in case we need someone to later */
+  if (mask == 0 && worker != NULL) {
+    watcher->next = &fd->inactive_watcher_root;
+    watcher->prev = watcher->next->prev;
+    watcher->next->prev = watcher->prev->next = watcher;
+  }
+  watcher->pollset = pollset;
+  watcher->worker = worker;
+  watcher->fd = fd;
+  gpr_mu_unlock(&fd->mu);
+
+  return mask;
+}
+
+static void fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *watcher,
+                        int got_read, int got_write) {
+  int was_polling = 0;
+  int kick = 0;
+  grpc_fd *fd = watcher->fd;
+
+  if (fd == NULL) {
+    return;
+  }
+
+  gpr_mu_lock(&fd->mu);
+
+  if (watcher == fd->read_watcher) {
+    /* remove read watcher, kick if we still need a read */
+    was_polling = 1;
+    if (!got_read) {
+      kick = 1;
+    }
+    fd->read_watcher = NULL;
+  }
+  if (watcher == fd->write_watcher) {
+    /* remove write watcher, kick if we still need a write */
+    was_polling = 1;
+    if (!got_write) {
+      kick = 1;
+    }
+    fd->write_watcher = NULL;
+  }
+  if (!was_polling && watcher->worker != NULL) {
+    /* remove from inactive list */
+    watcher->next->prev = watcher->prev;
+    watcher->prev->next = watcher->next;
+  }
+  if (got_read) {
+    if (set_ready_locked(exec_ctx, fd, &fd->read_closure)) {
+      kick = 1;
+    }
+  }
+  if (got_write) {
+    if (set_ready_locked(exec_ctx, fd, &fd->write_closure)) {
+      kick = 1;
+    }
+  }
+  if (kick) {
+    maybe_wake_one_watcher_locked(fd);
+  }
+  if (fd_is_orphaned(fd) && !has_watchers(fd) && !fd->closed) {
+    close_fd_locked(exec_ctx, fd);
+  }
+  gpr_mu_unlock(&fd->mu);
+
+  GRPC_FD_UNREF(fd, "poll");
+}
+
+/*******************************************************************************
+ * pollset_posix.c
+ */
+
+GPR_TLS_DECL(g_current_thread_poller);
+GPR_TLS_DECL(g_current_thread_worker);
+
+/** The alarm system needs to be able to wakeup 'some poller' sometimes
+ *  (specifically when a new alarm needs to be triggered earlier than the next
+ *  alarm 'epoch').
+ *  This wakeup_fd gives us something to alert on when such a case occurs. */
+grpc_wakeup_fd grpc_global_wakeup_fd;
+
+static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+  worker->prev->next = worker->next;
+  worker->next->prev = worker->prev;
+}
+
+static int pollset_has_workers(grpc_pollset *p) {
+  return p->root_worker.next != &p->root_worker;
+}
+
+static grpc_pollset_worker *pop_front_worker(grpc_pollset *p) {
+  if (pollset_has_workers(p)) {
+    grpc_pollset_worker *w = p->root_worker.next;
+    remove_worker(p, w);
+    return w;
+  } else {
+    return NULL;
+  }
+}
+
+static void push_back_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+  worker->next = &p->root_worker;
+  worker->prev = worker->next->prev;
+  worker->prev->next = worker->next->prev = worker;
+}
+
+static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+  worker->prev = &p->root_worker;
+  worker->next = worker->prev->next;
+  worker->prev->next = worker->next->prev = worker;
+}
+
+static void pollset_kick_ext(grpc_pollset *p,
+                             grpc_pollset_worker *specific_worker,
+                             uint32_t flags) {
+  GPR_TIMER_BEGIN("pollset_kick_ext", 0);
+
+  /* pollset->mu already held */
+  if (specific_worker != NULL) {
+    if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) {
+      GPR_TIMER_BEGIN("pollset_kick_ext.broadcast", 0);
+      GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
+      for (specific_worker = p->root_worker.next;
+           specific_worker != &p->root_worker;
+           specific_worker = specific_worker->next) {
+        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
+      }
+      p->kicked_without_pollers = 1;
+      GPR_TIMER_END("pollset_kick_ext.broadcast", 0);
+    } else if (gpr_tls_get(&g_current_thread_worker) !=
+               (intptr_t)specific_worker) {
+      GPR_TIMER_MARK("different_thread_worker", 0);
+      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
+        specific_worker->reevaluate_polling_on_wakeup = 1;
+      }
+      specific_worker->kicked_specifically = 1;
+      grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
+    } else if ((flags & GRPC_POLLSET_CAN_KICK_SELF) != 0) {
+      GPR_TIMER_MARK("kick_yoself", 0);
+      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
+        specific_worker->reevaluate_polling_on_wakeup = 1;
+      }
+      specific_worker->kicked_specifically = 1;
+      grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
+    }
+  } else if (gpr_tls_get(&g_current_thread_poller) != (intptr_t)p) {
+    GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
+    GPR_TIMER_MARK("kick_anonymous", 0);
+    specific_worker = pop_front_worker(p);
+    if (specific_worker != NULL) {
+      if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) {
+        GPR_TIMER_MARK("kick_anonymous_not_self", 0);
+        push_back_worker(p, specific_worker);
+        specific_worker = pop_front_worker(p);
+        if ((flags & GRPC_POLLSET_CAN_KICK_SELF) == 0 &&
+            gpr_tls_get(&g_current_thread_worker) ==
+                (intptr_t)specific_worker) {
+          push_back_worker(p, specific_worker);
+          specific_worker = NULL;
+        }
+      }
+      if (specific_worker != NULL) {
+        GPR_TIMER_MARK("finally_kick", 0);
+        push_back_worker(p, specific_worker);
+        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
+      }
+    } else {
+      GPR_TIMER_MARK("kicked_no_pollers", 0);
+      p->kicked_without_pollers = 1;
+    }
+  }
+
+  GPR_TIMER_END("pollset_kick_ext", 0);
+}
+
+static void pollset_kick(grpc_pollset *p,
+                         grpc_pollset_worker *specific_worker) {
+  pollset_kick_ext(p, specific_worker, 0);
+}
+
+/* global state management */
+
+static void pollset_global_init(void) {
+  gpr_tls_init(&g_current_thread_poller);
+  gpr_tls_init(&g_current_thread_worker);
+  grpc_wakeup_fd_global_init();
+  grpc_wakeup_fd_init(&grpc_global_wakeup_fd);
+}
+
+static void pollset_global_shutdown(void) {
+  grpc_wakeup_fd_destroy(&grpc_global_wakeup_fd);
+  gpr_tls_destroy(&g_current_thread_poller);
+  gpr_tls_destroy(&g_current_thread_worker);
+  grpc_wakeup_fd_global_destroy();
+}
+
+static void kick_poller(void) { grpc_wakeup_fd_wakeup(&grpc_global_wakeup_fd); }
+
+/* main interface */
+
+static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null);
+
+static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
+  gpr_mu_init(&pollset->mu);
+  *mu = &pollset->mu;
+  pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker;
+  pollset->in_flight_cbs = 0;
+  pollset->shutting_down = 0;
+  pollset->called_shutdown = 0;
+  pollset->kicked_without_pollers = 0;
+  pollset->idle_jobs.head = pollset->idle_jobs.tail = NULL;
+  pollset->local_wakeup_cache = NULL;
+  pollset->kicked_without_pollers = 0;
+  become_basic_pollset(pollset, NULL);
+}
+
+static void pollset_destroy(grpc_pollset *pollset) {
+  GPR_ASSERT(pollset->in_flight_cbs == 0);
+  GPR_ASSERT(!pollset_has_workers(pollset));
+  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
+  pollset->vtable->destroy(pollset);
+  while (pollset->local_wakeup_cache) {
+    grpc_cached_wakeup_fd *next = pollset->local_wakeup_cache->next;
+    grpc_wakeup_fd_destroy(&pollset->local_wakeup_cache->fd);
+    gpr_free(pollset->local_wakeup_cache);
+    pollset->local_wakeup_cache = next;
+  }
+  gpr_mu_destroy(&pollset->mu);
+}
+
+static void pollset_reset(grpc_pollset *pollset) {
+  GPR_ASSERT(pollset->shutting_down);
+  GPR_ASSERT(pollset->in_flight_cbs == 0);
+  GPR_ASSERT(!pollset_has_workers(pollset));
+  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
+  pollset->vtable->destroy(pollset);
+  pollset->shutting_down = 0;
+  pollset->called_shutdown = 0;
+  pollset->kicked_without_pollers = 0;
+  become_basic_pollset(pollset, NULL);
+}
+
+static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_fd *fd) {
+  gpr_mu_lock(&pollset->mu);
+  pollset->vtable->add_fd(exec_ctx, pollset, fd, 1);
+/* the following (enabled only in debug) will reacquire and then release
+   our lock - meaning that if the unlocking flag passed to add_fd above is
+   not respected, the code will deadlock (in a way that we have a chance of
+   debugging) */
+#ifndef NDEBUG
+  gpr_mu_lock(&pollset->mu);
+  gpr_mu_unlock(&pollset->mu);
+#endif
+}
+
+static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
+  GPR_ASSERT(grpc_closure_list_empty(pollset->idle_jobs));
+  pollset->vtable->finish_shutdown(pollset);
+  grpc_exec_ctx_enqueue(exec_ctx, pollset->shutdown_done, true, NULL);
+}
+
+static void pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         grpc_pollset_worker **worker_hdl, gpr_timespec now,
+                         gpr_timespec deadline) {
+  grpc_pollset_worker worker;
+  *worker_hdl = &worker;
+
+  /* pollset->mu already held */
+  int added_worker = 0;
+  int locked = 1;
+  int queued_work = 0;
+  int keep_polling = 0;
+  GPR_TIMER_BEGIN("pollset_work", 0);
+  /* this must happen before we (potentially) drop pollset->mu */
+  worker.next = worker.prev = NULL;
+  worker.reevaluate_polling_on_wakeup = 0;
+  if (pollset->local_wakeup_cache != NULL) {
+    worker.wakeup_fd = pollset->local_wakeup_cache;
+    pollset->local_wakeup_cache = worker.wakeup_fd->next;
+  } else {
+    worker.wakeup_fd = gpr_malloc(sizeof(*worker.wakeup_fd));
+    grpc_wakeup_fd_init(&worker.wakeup_fd->fd);
+  }
+  worker.kicked_specifically = 0;
+  /* If there's work waiting for the pollset to be idle, and the
+     pollset is idle, then do that work */
+  if (!pollset_has_workers(pollset) &&
+      !grpc_closure_list_empty(pollset->idle_jobs)) {
+    GPR_TIMER_MARK("pollset_work.idle_jobs", 0);
+    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
+    goto done;
+  }
+  /* If we're shutting down then we don't execute any extended work */
+  if (pollset->shutting_down) {
+    GPR_TIMER_MARK("pollset_work.shutting_down", 0);
+    goto done;
+  }
+  /* Give do_promote priority so we don't starve it out */
+  if (pollset->in_flight_cbs) {
+    GPR_TIMER_MARK("pollset_work.in_flight_cbs", 0);
+    gpr_mu_unlock(&pollset->mu);
+    locked = 0;
+    goto done;
+  }
+  /* Start polling, and keep doing so while we're being asked to
+     re-evaluate our pollers (this allows poll() based pollers to
+     ensure they don't miss wakeups) */
+  keep_polling = 1;
+  while (keep_polling) {
+    keep_polling = 0;
+    if (!pollset->kicked_without_pollers) {
+      if (!added_worker) {
+        push_front_worker(pollset, &worker);
+        added_worker = 1;
+        gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
+      }
+      gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset);
+      GPR_TIMER_BEGIN("maybe_work_and_unlock", 0);
+      pollset->vtable->maybe_work_and_unlock(exec_ctx, pollset, &worker,
+                                             deadline, now);
+      GPR_TIMER_END("maybe_work_and_unlock", 0);
+      locked = 0;
+      gpr_tls_set(&g_current_thread_poller, 0);
+    } else {
+      GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0);
+      pollset->kicked_without_pollers = 0;
+    }
+  /* Finished execution - start cleaning up.
+     Note that we may arrive here from outside the enclosing while() loop.
+     In that case we won't loop though as we haven't added worker to the
+     worker list, which means nobody could ask us to re-evaluate polling). */
+  done:
+    if (!locked) {
+      queued_work |= grpc_exec_ctx_flush(exec_ctx);
+      gpr_mu_lock(&pollset->mu);
+      locked = 1;
+    }
+    /* If we're forced to re-evaluate polling (via pollset_kick with
+       GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force
+       a loop */
+    if (worker.reevaluate_polling_on_wakeup) {
+      worker.reevaluate_polling_on_wakeup = 0;
+      pollset->kicked_without_pollers = 0;
+      if (queued_work || worker.kicked_specifically) {
+        /* If there's queued work on the list, then set the deadline to be
+           immediate so we get back out of the polling loop quickly */
+        deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+      }
+      keep_polling = 1;
+    }
+  }
+  if (added_worker) {
+    remove_worker(pollset, &worker);
+    gpr_tls_set(&g_current_thread_worker, 0);
+  }
+  /* release wakeup fd to the local pool */
+  worker.wakeup_fd->next = pollset->local_wakeup_cache;
+  pollset->local_wakeup_cache = worker.wakeup_fd;
+  /* check shutdown conditions */
+  if (pollset->shutting_down) {
+    if (pollset_has_workers(pollset)) {
+      pollset_kick(pollset, NULL);
+    } else if (!pollset->called_shutdown && pollset->in_flight_cbs == 0) {
+      pollset->called_shutdown = 1;
+      gpr_mu_unlock(&pollset->mu);
+      finish_shutdown(exec_ctx, pollset);
+      grpc_exec_ctx_flush(exec_ctx);
+      /* Continuing to access pollset here is safe -- it is the caller's
+       * responsibility to not destroy when it has outstanding calls to
+       * pollset_work.
+       * TODO(dklempner): Can we refactor the shutdown logic to avoid this? */
+      gpr_mu_lock(&pollset->mu);
+    } else if (!grpc_closure_list_empty(pollset->idle_jobs)) {
+      grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
+      gpr_mu_unlock(&pollset->mu);
+      grpc_exec_ctx_flush(exec_ctx);
+      gpr_mu_lock(&pollset->mu);
+    }
+  }
+  *worker_hdl = NULL;
+  GPR_TIMER_END("pollset_work", 0);
+}
+
+static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                             grpc_closure *closure) {
+  GPR_ASSERT(!pollset->shutting_down);
+  pollset->shutting_down = 1;
+  pollset->shutdown_done = closure;
+  pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
+  if (!pollset_has_workers(pollset)) {
+    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
+  }
+  if (!pollset->called_shutdown && pollset->in_flight_cbs == 0 &&
+      !pollset_has_workers(pollset)) {
+    pollset->called_shutdown = 1;
+    finish_shutdown(exec_ctx, pollset);
+  }
+}
+
+static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
+                                           gpr_timespec now) {
+  gpr_timespec timeout;
+  static const int64_t max_spin_polling_us = 10;
+  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
+    return -1;
+  }
+  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
+                                                   max_spin_polling_us,
+                                                   GPR_TIMESPAN))) <= 0) {
+    return 0;
+  }
+  timeout = gpr_time_sub(deadline, now);
+  return gpr_time_to_millis(gpr_time_add(
+      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
+}
+
+/*
+ * basic_pollset - a vtable that provides polling for zero or one file
+ *                 descriptor via poll()
+ */
+
+typedef struct grpc_unary_promote_args {
+  const grpc_pollset_vtable *original_vtable;
+  grpc_pollset *pollset;
+  grpc_fd *fd;
+  grpc_closure promotion_closure;
+} grpc_unary_promote_args;
+
+static void basic_do_promote(grpc_exec_ctx *exec_ctx, void *args,
+                             bool success) {
+  grpc_unary_promote_args *up_args = args;
+  const grpc_pollset_vtable *original_vtable = up_args->original_vtable;
+  grpc_pollset *pollset = up_args->pollset;
+  grpc_fd *fd = up_args->fd;
+
+  /*
+   * This is quite tricky. There are a number of cases to keep in mind here:
+   * 1. fd may have been orphaned
+   * 2. The pollset may no longer be a unary poller (and we can't let case #1
+   * leak to other pollset types!)
+   * 3. pollset's fd (which may have changed) may have been orphaned
+   * 4. The pollset may be shutting down.
+   */
+
+  gpr_mu_lock(&pollset->mu);
+  /* First we need to ensure that nobody is polling concurrently */
+  GPR_ASSERT(!pollset_has_workers(pollset));
+
+  gpr_free(up_args);
+  /* At this point the pollset may no longer be a unary poller. In that case
+   * we should just call the right add function and be done. */
+  /* TODO(klempner): If we're not careful this could cause infinite recursion.
+   * That's not a problem for now because empty_pollset has a trivial poller
+   * and we don't have any mechanism to unbecome multipoller. */
+  pollset->in_flight_cbs--;
+  if (pollset->shutting_down) {
+    /* We don't care about this pollset anymore. */
+    if (pollset->in_flight_cbs == 0 && !pollset->called_shutdown) {
+      pollset->called_shutdown = 1;
+      finish_shutdown(exec_ctx, pollset);
+    }
+  } else if (fd_is_orphaned(fd)) {
+    /* Don't try to add it to anything, we'll drop our ref on it below */
+  } else if (pollset->vtable != original_vtable) {
+    pollset->vtable->add_fd(exec_ctx, pollset, fd, 0);
+  } else if (fd != pollset->data.ptr) {
+    grpc_fd *fds[2];
+    fds[0] = pollset->data.ptr;
+    fds[1] = fd;
+
+    if (fds[0] && !fd_is_orphaned(fds[0])) {
+      platform_become_multipoller(exec_ctx, pollset, fds, GPR_ARRAY_SIZE(fds));
+      GRPC_FD_UNREF(fds[0], "basicpoll");
+    } else {
+      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
+       * unary poller */
+      /* Note that it is possible that fds[1] is also orphaned at this point.
+       * That's okay, we'll correct it at the next add or poll. */
+      if (fds[0]) GRPC_FD_UNREF(fds[0], "basicpoll");
+      pollset->data.ptr = fd;
+      GRPC_FD_REF(fd, "basicpoll");
+    }
+  }
+
+  gpr_mu_unlock(&pollset->mu);
+
+  /* Matching ref in basic_pollset_add_fd */
+  GRPC_FD_UNREF(fd, "basicpoll_add");
+}
+
+static void basic_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                                 grpc_fd *fd, int and_unlock_pollset) {
+  grpc_unary_promote_args *up_args;
+  GPR_ASSERT(fd);
+  if (fd == pollset->data.ptr) goto exit;
+
+  if (!pollset_has_workers(pollset)) {
+    /* Fast path -- no in flight cbs */
+    /* TODO(klempner): Comment this out and fix any test failures or establish
+     * they are due to timing issues */
+    grpc_fd *fds[2];
+    fds[0] = pollset->data.ptr;
+    fds[1] = fd;
+
+    if (fds[0] == NULL) {
+      pollset->data.ptr = fd;
+      GRPC_FD_REF(fd, "basicpoll");
+    } else if (!fd_is_orphaned(fds[0])) {
+      platform_become_multipoller(exec_ctx, pollset, fds, GPR_ARRAY_SIZE(fds));
+      GRPC_FD_UNREF(fds[0], "basicpoll");
+    } else {
+      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
+       * unary poller */
+      GRPC_FD_UNREF(fds[0], "basicpoll");
+      pollset->data.ptr = fd;
+      GRPC_FD_REF(fd, "basicpoll");
+    }
+    goto exit;
+  }
+
+  /* Now we need to promote. This needs to happen when we're not polling. Since
+   * this may be called from poll, the wait needs to happen asynchronously. */
+  GRPC_FD_REF(fd, "basicpoll_add");
+  pollset->in_flight_cbs++;
+  up_args = gpr_malloc(sizeof(*up_args));
+  up_args->fd = fd;
+  up_args->original_vtable = pollset->vtable;
+  up_args->pollset = pollset;
+  up_args->promotion_closure.cb = basic_do_promote;
+  up_args->promotion_closure.cb_arg = up_args;
+
+  grpc_closure_list_add(&pollset->idle_jobs, &up_args->promotion_closure, 1);
+  pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
+
+exit:
+  if (and_unlock_pollset) {
+    gpr_mu_unlock(&pollset->mu);
+  }
+}
+
+static void basic_pollset_maybe_work_and_unlock(grpc_exec_ctx *exec_ctx,
+                                                grpc_pollset *pollset,
+                                                grpc_pollset_worker *worker,
+                                                gpr_timespec deadline,
+                                                gpr_timespec now) {
+#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
+#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
+
+  struct pollfd pfd[3];
+  grpc_fd *fd;
+  grpc_fd_watcher fd_watcher;
+  int timeout;
+  int r;
+  nfds_t nfds;
+
+  fd = pollset->data.ptr;
+  if (fd && fd_is_orphaned(fd)) {
+    GRPC_FD_UNREF(fd, "basicpoll");
+    fd = pollset->data.ptr = NULL;
+  }
+  timeout = poll_deadline_to_millis_timeout(deadline, now);
+  pfd[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
+  pfd[0].events = POLLIN;
+  pfd[0].revents = 0;
+  pfd[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
+  pfd[1].events = POLLIN;
+  pfd[1].revents = 0;
+  nfds = 2;
+  if (fd) {
+    pfd[2].fd = fd->fd;
+    pfd[2].revents = 0;
+    GRPC_FD_REF(fd, "basicpoll_begin");
+    gpr_mu_unlock(&pollset->mu);
+    pfd[2].events =
+        (short)fd_begin_poll(fd, pollset, worker, POLLIN, POLLOUT, &fd_watcher);
+    if (pfd[2].events != 0) {
+      nfds++;
+    }
+  } else {
+    gpr_mu_unlock(&pollset->mu);
+  }
+
+  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
+     even going into the blocking annotation if possible */
+  /* poll fd count (argument 2) is shortened by one if we have no events
+     to poll on - such that it only includes the kicker */
+  GPR_TIMER_BEGIN("poll", 0);
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
+  r = grpc_poll_function(pfd, nfds, timeout);
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GPR_TIMER_END("poll", 0);
+
+  if (r < 0) {
+    if (errno != EINTR) {
+      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
+    }
+    if (fd) {
+      fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
+    }
+  } else if (r == 0) {
+    if (fd) {
+      fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
+    }
+  } else {
+    if (pfd[0].revents & POLLIN_CHECK) {
+      grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
+    }
+    if (pfd[1].revents & POLLIN_CHECK) {
+      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
+    }
+    if (nfds > 2) {
+      fd_end_poll(exec_ctx, &fd_watcher, pfd[2].revents & POLLIN_CHECK,
+                  pfd[2].revents & POLLOUT_CHECK);
+    } else if (fd) {
+      fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
+    }
+  }
+
+  if (fd) {
+    GRPC_FD_UNREF(fd, "basicpoll_begin");
+  }
+}
+
+static void basic_pollset_destroy(grpc_pollset *pollset) {
+  if (pollset->data.ptr != NULL) {
+    GRPC_FD_UNREF(pollset->data.ptr, "basicpoll");
+    pollset->data.ptr = NULL;
+  }
+}
+
+static const grpc_pollset_vtable basic_pollset = {
+    basic_pollset_add_fd, basic_pollset_maybe_work_and_unlock,
+    basic_pollset_destroy, basic_pollset_destroy};
+
+static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
+  pollset->vtable = &basic_pollset;
+  pollset->data.ptr = fd_or_null;
+  if (fd_or_null != NULL) {
+    GRPC_FD_REF(fd_or_null, "basicpoll");
+  }
+}
+
+/*******************************************************************************
+ * pollset_multipoller_with_poll_posix.c
+ */
+
+#ifndef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+
+typedef struct {
+  /* all polled fds */
+  size_t fd_count;
+  size_t fd_capacity;
+  grpc_fd **fds;
+  /* fds that have been removed from the pollset explicitly */
+  size_t del_count;
+  size_t del_capacity;
+  grpc_fd **dels;
+} poll_hdr;
+
+static void multipoll_with_poll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
+                                               grpc_pollset *pollset,
+                                               grpc_fd *fd,
+                                               int and_unlock_pollset) {
+  size_t i;
+  poll_hdr *h = pollset->data.ptr;
+  /* TODO(ctiller): this is O(num_fds^2); maybe switch to a hash set here */
+  for (i = 0; i < h->fd_count; i++) {
+    if (h->fds[i] == fd) goto exit;
+  }
+  if (h->fd_count == h->fd_capacity) {
+    h->fd_capacity = GPR_MAX(h->fd_capacity + 8, h->fd_count * 3 / 2);
+    h->fds = gpr_realloc(h->fds, sizeof(grpc_fd *) * h->fd_capacity);
+  }
+  h->fds[h->fd_count++] = fd;
+  GRPC_FD_REF(fd, "multipoller");
+exit:
+  if (and_unlock_pollset) {
+    gpr_mu_unlock(&pollset->mu);
+  }
+}
+
+static void multipoll_with_poll_pollset_maybe_work_and_unlock(
+    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
+    gpr_timespec deadline, gpr_timespec now) {
+#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
+#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
+
+  int timeout;
+  int r;
+  size_t i, j, fd_count;
+  nfds_t pfd_count;
+  poll_hdr *h;
+  /* TODO(ctiller): inline some elements to avoid an allocation */
+  grpc_fd_watcher *watchers;
+  struct pollfd *pfds;
+
+  h = pollset->data.ptr;
+  timeout = poll_deadline_to_millis_timeout(deadline, now);
+  /* TODO(ctiller): perform just one malloc here if we exceed the inline case */
+  pfds = gpr_malloc(sizeof(*pfds) * (h->fd_count + 2));
+  watchers = gpr_malloc(sizeof(*watchers) * (h->fd_count + 2));
+  fd_count = 0;
+  pfd_count = 2;
+  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
+  pfds[0].events = POLLIN;
+  pfds[0].revents = 0;
+  pfds[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
+  pfds[1].events = POLLIN;
+  pfds[1].revents = 0;
+  for (i = 0; i < h->fd_count; i++) {
+    int remove = fd_is_orphaned(h->fds[i]);
+    for (j = 0; !remove && j < h->del_count; j++) {
+      if (h->fds[i] == h->dels[j]) remove = 1;
+    }
+    if (remove) {
+      GRPC_FD_UNREF(h->fds[i], "multipoller");
+    } else {
+      h->fds[fd_count++] = h->fds[i];
+      watchers[pfd_count].fd = h->fds[i];
+      GRPC_FD_REF(watchers[pfd_count].fd, "multipoller_start");
+      pfds[pfd_count].fd = h->fds[i]->fd;
+      pfds[pfd_count].revents = 0;
+      pfd_count++;
+    }
+  }
+  for (j = 0; j < h->del_count; j++) {
+    GRPC_FD_UNREF(h->dels[j], "multipoller_del");
+  }
+  h->del_count = 0;
+  h->fd_count = fd_count;
+  gpr_mu_unlock(&pollset->mu);
+
+  for (i = 2; i < pfd_count; i++) {
+    grpc_fd *fd = watchers[i].fd;
+    pfds[i].events = (short)fd_begin_poll(fd, pollset, worker, POLLIN, POLLOUT,
+                                          &watchers[i]);
+    GRPC_FD_UNREF(fd, "multipoller_start");
+  }
+
+  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
+     even going into the blocking annotation if possible */
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
+  r = grpc_poll_function(pfds, pfd_count, timeout);
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
+
+  if (r < 0) {
+    if (errno != EINTR) {
+      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
+    }
+    for (i = 2; i < pfd_count; i++) {
+      fd_end_poll(exec_ctx, &watchers[i], 0, 0);
+    }
+  } else if (r == 0) {
+    for (i = 2; i < pfd_count; i++) {
+      fd_end_poll(exec_ctx, &watchers[i], 0, 0);
+    }
+  } else {
+    if (pfds[0].revents & POLLIN_CHECK) {
+      grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
+    }
+    if (pfds[1].revents & POLLIN_CHECK) {
+      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
+    }
+    for (i = 2; i < pfd_count; i++) {
+      if (watchers[i].fd == NULL) {
+        fd_end_poll(exec_ctx, &watchers[i], 0, 0);
+        continue;
+      }
+      fd_end_poll(exec_ctx, &watchers[i], pfds[i].revents & POLLIN_CHECK,
+                  pfds[i].revents & POLLOUT_CHECK);
+    }
+  }
+
+  gpr_free(pfds);
+  gpr_free(watchers);
+}
+
+static void multipoll_with_poll_pollset_finish_shutdown(grpc_pollset *pollset) {
+  size_t i;
+  poll_hdr *h = pollset->data.ptr;
+  for (i = 0; i < h->fd_count; i++) {
+    GRPC_FD_UNREF(h->fds[i], "multipoller");
+  }
+  for (i = 0; i < h->del_count; i++) {
+    GRPC_FD_UNREF(h->dels[i], "multipoller_del");
+  }
+  h->fd_count = 0;
+  h->del_count = 0;
+}
+
+static void multipoll_with_poll_pollset_destroy(grpc_pollset *pollset) {
+  poll_hdr *h = pollset->data.ptr;
+  multipoll_with_poll_pollset_finish_shutdown(pollset);
+  gpr_free(h->fds);
+  gpr_free(h->dels);
+  gpr_free(h);
+}
+
+static const grpc_pollset_vtable multipoll_with_poll_pollset = {
+    multipoll_with_poll_pollset_add_fd,
+    multipoll_with_poll_pollset_maybe_work_and_unlock,
+    multipoll_with_poll_pollset_finish_shutdown,
+    multipoll_with_poll_pollset_destroy};
+
+static void poll_become_multipoller(grpc_exec_ctx *exec_ctx,
+                                    grpc_pollset *pollset, grpc_fd **fds,
+                                    size_t nfds) {
+  size_t i;
+  poll_hdr *h = gpr_malloc(sizeof(poll_hdr));
+  pollset->vtable = &multipoll_with_poll_pollset;
+  pollset->data.ptr = h;
+  h->fd_count = nfds;
+  h->fd_capacity = nfds;
+  h->fds = gpr_malloc(nfds * sizeof(grpc_fd *));
+  h->del_count = 0;
+  h->del_capacity = 0;
+  h->dels = NULL;
+  for (i = 0; i < nfds; i++) {
+    h->fds[i] = fds[i];
+    GRPC_FD_REF(fds[i], "multipoller");
+  }
+}
+
+#endif /* !GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+
+/*******************************************************************************
+ * pollset_multipoller_with_epoll_posix.c
+ */
+
+#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+
+#include <errno.h>
+#include <poll.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/block_annotate.h"
+
+static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure **st) {
+  /* only one set_ready can be active at once (but there may be a racing
+     notify_on) */
+  gpr_mu_lock(&fd->mu);
+  set_ready_locked(exec_ctx, fd, st);
+  gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+  set_ready(exec_ctx, fd, &fd->read_closure);
+}
+
+static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+  set_ready(exec_ctx, fd, &fd->write_closure);
+}
+
+struct epoll_fd_list {
+  int *epoll_fds;
+  size_t count;
+  size_t capacity;
+};
+
+static struct epoll_fd_list epoll_fd_global_list;
+static gpr_once init_epoll_fd_list_mu = GPR_ONCE_INIT;
+static gpr_mu epoll_fd_list_mu;
+
+static void init_mu(void) { gpr_mu_init(&epoll_fd_list_mu); }
+
+static void add_epoll_fd_to_global_list(int epoll_fd) {
+  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
+
+  gpr_mu_lock(&epoll_fd_list_mu);
+  if (epoll_fd_global_list.count == epoll_fd_global_list.capacity) {
+    epoll_fd_global_list.capacity =
+        GPR_MAX((size_t)8, epoll_fd_global_list.capacity * 2);
+    epoll_fd_global_list.epoll_fds =
+        gpr_realloc(epoll_fd_global_list.epoll_fds,
+                    epoll_fd_global_list.capacity * sizeof(int));
+  }
+  epoll_fd_global_list.epoll_fds[epoll_fd_global_list.count++] = epoll_fd;
+  gpr_mu_unlock(&epoll_fd_list_mu);
+}
+
+static void remove_epoll_fd_from_global_list(int epoll_fd) {
+  gpr_mu_lock(&epoll_fd_list_mu);
+  GPR_ASSERT(epoll_fd_global_list.count > 0);
+  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
+    if (epoll_fd == epoll_fd_global_list.epoll_fds[i]) {
+      epoll_fd_global_list.epoll_fds[i] =
+          epoll_fd_global_list.epoll_fds[--(epoll_fd_global_list.count)];
+      break;
+    }
+  }
+  gpr_mu_unlock(&epoll_fd_list_mu);
+}
+
+static void remove_fd_from_all_epoll_sets(int fd) {
+  int err;
+  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
+  gpr_mu_lock(&epoll_fd_list_mu);
+  if (epoll_fd_global_list.count == 0) {
+    gpr_mu_unlock(&epoll_fd_list_mu);
+    return;
+  }
+  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
+    err = epoll_ctl(epoll_fd_global_list.epoll_fds[i], EPOLL_CTL_DEL, fd, NULL);
+    if (err < 0 && errno != ENOENT) {
+      gpr_log(GPR_ERROR, "epoll_ctl del for %d failed: %s", fd,
+              strerror(errno));
+    }
+  }
+  gpr_mu_unlock(&epoll_fd_list_mu);
+}
+
+typedef struct {
+  grpc_pollset *pollset;
+  grpc_fd *fd;
+  grpc_closure closure;
+} delayed_add;
+
+typedef struct { int epoll_fd; } epoll_hdr;
+
+static void finally_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_fd *fd) {
+  epoll_hdr *h = pollset->data.ptr;
+  struct epoll_event ev;
+  int err;
+  grpc_fd_watcher watcher;
+
+  /* We pretend to be polling whilst adding an fd to keep the fd from being
+     closed during the add. This may result in a spurious wakeup being assigned
+     to this pollset whilst adding, but that should be benign. */
+  GPR_ASSERT(fd_begin_poll(fd, pollset, NULL, 0, 0, &watcher) == 0);
+  if (watcher.fd != NULL) {
+    ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
+    ev.data.ptr = fd;
+    err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev);
+    if (err < 0) {
+      /* FDs may be added to a pollset multiple times, so EEXIST is normal. */
+      if (errno != EEXIST) {
+        gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd,
+                strerror(errno));
+      }
+    }
+  }
+  fd_end_poll(exec_ctx, &watcher, 0, 0);
+}
+
+static void perform_delayed_add(grpc_exec_ctx *exec_ctx, void *arg,
+                                bool iomgr_status) {
+  delayed_add *da = arg;
+
+  if (!fd_is_orphaned(da->fd)) {
+    finally_add_fd(exec_ctx, da->pollset, da->fd);
+  }
+
+  gpr_mu_lock(&da->pollset->mu);
+  da->pollset->in_flight_cbs--;
+  if (da->pollset->shutting_down) {
+    /* We don't care about this pollset anymore. */
+    if (da->pollset->in_flight_cbs == 0 && !da->pollset->called_shutdown) {
+      da->pollset->called_shutdown = 1;
+      grpc_exec_ctx_enqueue(exec_ctx, da->pollset->shutdown_done, true, NULL);
+    }
+  }
+  gpr_mu_unlock(&da->pollset->mu);
+
+  GRPC_FD_UNREF(da->fd, "delayed_add");
+
+  gpr_free(da);
+}
+
+static void multipoll_with_epoll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
+                                                grpc_pollset *pollset,
+                                                grpc_fd *fd,
+                                                int and_unlock_pollset) {
+  if (and_unlock_pollset) {
+    gpr_mu_unlock(&pollset->mu);
+    finally_add_fd(exec_ctx, pollset, fd);
+  } else {
+    delayed_add *da = gpr_malloc(sizeof(*da));
+    da->pollset = pollset;
+    da->fd = fd;
+    GRPC_FD_REF(fd, "delayed_add");
+    grpc_closure_init(&da->closure, perform_delayed_add, da);
+    pollset->in_flight_cbs++;
+    grpc_exec_ctx_enqueue(exec_ctx, &da->closure, true, NULL);
+  }
+}
+
+/* TODO(klempner): We probably want to turn this down a bit */
+#define GRPC_EPOLL_MAX_EVENTS 1000
+
+static void multipoll_with_epoll_pollset_maybe_work_and_unlock(
+    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
+    gpr_timespec deadline, gpr_timespec now) {
+  struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
+  int ep_rv;
+  int poll_rv;
+  epoll_hdr *h = pollset->data.ptr;
+  int timeout_ms;
+  struct pollfd pfds[2];
+
+  /* If you want to ignore epoll's ability to sanely handle parallel pollers,
+   * for a more apples-to-apples performance comparison with poll, add a
+   * if (pollset->counter != 0) { return 0; }
+   * here.
+   */
+
+  gpr_mu_unlock(&pollset->mu);
+
+  timeout_ms = poll_deadline_to_millis_timeout(deadline, now);
+
+  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
+  pfds[0].events = POLLIN;
+  pfds[0].revents = 0;
+  pfds[1].fd = h->epoll_fd;
+  pfds[1].events = POLLIN;
+  pfds[1].revents = 0;
+
+  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
+     even going into the blocking annotation if possible */
+  GPR_TIMER_BEGIN("poll", 0);
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
+  poll_rv = grpc_poll_function(pfds, 2, timeout_ms);
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
+  GPR_TIMER_END("poll", 0);
+
+  if (poll_rv < 0) {
+    if (errno != EINTR) {
+      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
+    }
+  } else if (poll_rv == 0) {
+    /* do nothing */
+  } else {
+    if (pfds[0].revents) {
+      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
+    }
+    if (pfds[1].revents) {
+      do {
+        /* The following epoll_wait never blocks; it has a timeout of 0 */
+        ep_rv = epoll_wait(h->epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
+        if (ep_rv < 0) {
+          if (errno != EINTR) {
+            gpr_log(GPR_ERROR, "epoll_wait() failed: %s", strerror(errno));
+          }
+        } else {
+          int i;
+          for (i = 0; i < ep_rv; ++i) {
+            grpc_fd *fd = ep_ev[i].data.ptr;
+            /* TODO(klempner): We might want to consider making err and pri
+             * separate events */
+            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 (fd == NULL) {
+              grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
+            } else {
+              if (read_ev || cancel) {
+                fd_become_readable(exec_ctx, fd);
+              }
+              if (write_ev || cancel) {
+                fd_become_writable(exec_ctx, fd);
+              }
+            }
+          }
+        }
+      } while (ep_rv == GRPC_EPOLL_MAX_EVENTS);
+    }
+  }
+}
+
+static void multipoll_with_epoll_pollset_finish_shutdown(
+    grpc_pollset *pollset) {}
+
+static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset) {
+  epoll_hdr *h = pollset->data.ptr;
+  close(h->epoll_fd);
+  remove_epoll_fd_from_global_list(h->epoll_fd);
+  gpr_free(h);
+}
+
+static const grpc_pollset_vtable multipoll_with_epoll_pollset = {
+    multipoll_with_epoll_pollset_add_fd,
+    multipoll_with_epoll_pollset_maybe_work_and_unlock,
+    multipoll_with_epoll_pollset_finish_shutdown,
+    multipoll_with_epoll_pollset_destroy};
+
+static void epoll_become_multipoller(grpc_exec_ctx *exec_ctx,
+                                     grpc_pollset *pollset, grpc_fd **fds,
+                                     size_t nfds) {
+  size_t i;
+  epoll_hdr *h = gpr_malloc(sizeof(epoll_hdr));
+  struct epoll_event ev;
+  int err;
+
+  pollset->vtable = &multipoll_with_epoll_pollset;
+  pollset->data.ptr = h;
+  h->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+  if (h->epoll_fd < 0) {
+    /* TODO(klempner): Fall back to poll here, especially on ENOSYS */
+    gpr_log(GPR_ERROR, "epoll_create1 failed: %s", strerror(errno));
+    abort();
+  }
+  add_epoll_fd_to_global_list(h->epoll_fd);
+
+  ev.events = (uint32_t)(EPOLLIN | EPOLLET);
+  ev.data.ptr = NULL;
+  err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD,
+                  GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), &ev);
+  if (err < 0) {
+    gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s",
+            GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd),
+            strerror(errno));
+  }
+
+  for (i = 0; i < nfds; i++) {
+    multipoll_with_epoll_pollset_add_fd(exec_ctx, pollset, fds[i], 0);
+  }
+}
+
+#else /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+
+static void remove_fd_from_all_epoll_sets(int fd) {}
+
+#endif /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+
+/*******************************************************************************
+ * pollset_set_posix.c
+ */
+
+static grpc_pollset_set *pollset_set_create(void) {
+  grpc_pollset_set *pollset_set = gpr_malloc(sizeof(*pollset_set));
+  memset(pollset_set, 0, sizeof(*pollset_set));
+  gpr_mu_init(&pollset_set->mu);
+  return pollset_set;
+}
+
+static void pollset_set_destroy(grpc_pollset_set *pollset_set) {
+  size_t i;
+  gpr_mu_destroy(&pollset_set->mu);
+  for (i = 0; i < pollset_set->fd_count; i++) {
+    GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
+  }
+  gpr_free(pollset_set->pollsets);
+  gpr_free(pollset_set->pollset_sets);
+  gpr_free(pollset_set->fds);
+  gpr_free(pollset_set);
+}
+
+static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
+                                    grpc_pollset_set *pollset_set,
+                                    grpc_pollset *pollset) {
+  size_t i, j;
+  gpr_mu_lock(&pollset_set->mu);
+  if (pollset_set->pollset_count == pollset_set->pollset_capacity) {
+    pollset_set->pollset_capacity =
+        GPR_MAX(8, 2 * pollset_set->pollset_capacity);
+    pollset_set->pollsets =
+        gpr_realloc(pollset_set->pollsets, pollset_set->pollset_capacity *
+                                               sizeof(*pollset_set->pollsets));
+  }
+  pollset_set->pollsets[pollset_set->pollset_count++] = pollset;
+  for (i = 0, j = 0; i < pollset_set->fd_count; i++) {
+    if (fd_is_orphaned(pollset_set->fds[i])) {
+      GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
+    } else {
+      pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]);
+      pollset_set->fds[j++] = pollset_set->fds[i];
+    }
+  }
+  pollset_set->fd_count = j;
+  gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
+                                    grpc_pollset_set *pollset_set,
+                                    grpc_pollset *pollset) {
+  size_t i;
+  gpr_mu_lock(&pollset_set->mu);
+  for (i = 0; i < pollset_set->pollset_count; i++) {
+    if (pollset_set->pollsets[i] == pollset) {
+      pollset_set->pollset_count--;
+      GPR_SWAP(grpc_pollset *, pollset_set->pollsets[i],
+               pollset_set->pollsets[pollset_set->pollset_count]);
+      break;
+    }
+  }
+  gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
+                                        grpc_pollset_set *bag,
+                                        grpc_pollset_set *item) {
+  size_t i, j;
+  gpr_mu_lock(&bag->mu);
+  if (bag->pollset_set_count == bag->pollset_set_capacity) {
+    bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity);
+    bag->pollset_sets =
+        gpr_realloc(bag->pollset_sets,
+                    bag->pollset_set_capacity * sizeof(*bag->pollset_sets));
+  }
+  bag->pollset_sets[bag->pollset_set_count++] = item;
+  for (i = 0, j = 0; i < bag->fd_count; i++) {
+    if (fd_is_orphaned(bag->fds[i])) {
+      GRPC_FD_UNREF(bag->fds[i], "pollset_set");
+    } else {
+      pollset_set_add_fd(exec_ctx, item, bag->fds[i]);
+      bag->fds[j++] = bag->fds[i];
+    }
+  }
+  bag->fd_count = j;
+  gpr_mu_unlock(&bag->mu);
+}
+
+static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
+                                        grpc_pollset_set *bag,
+                                        grpc_pollset_set *item) {
+  size_t i;
+  gpr_mu_lock(&bag->mu);
+  for (i = 0; i < bag->pollset_set_count; i++) {
+    if (bag->pollset_sets[i] == item) {
+      bag->pollset_set_count--;
+      GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i],
+               bag->pollset_sets[bag->pollset_set_count]);
+      break;
+    }
+  }
+  gpr_mu_unlock(&bag->mu);
+}
+
+static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
+                               grpc_pollset_set *pollset_set, grpc_fd *fd) {
+  size_t i;
+  gpr_mu_lock(&pollset_set->mu);
+  if (pollset_set->fd_count == pollset_set->fd_capacity) {
+    pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity);
+    pollset_set->fds = gpr_realloc(
+        pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds));
+  }
+  GRPC_FD_REF(fd, "pollset_set");
+  pollset_set->fds[pollset_set->fd_count++] = fd;
+  for (i = 0; i < pollset_set->pollset_count; i++) {
+    pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd);
+  }
+  for (i = 0; i < pollset_set->pollset_set_count; i++) {
+    pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+  }
+  gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
+                               grpc_pollset_set *pollset_set, grpc_fd *fd) {
+  size_t i;
+  gpr_mu_lock(&pollset_set->mu);
+  for (i = 0; i < pollset_set->fd_count; i++) {
+    if (pollset_set->fds[i] == fd) {
+      pollset_set->fd_count--;
+      GPR_SWAP(grpc_fd *, pollset_set->fds[i],
+               pollset_set->fds[pollset_set->fd_count]);
+      GRPC_FD_UNREF(fd, "pollset_set");
+      break;
+    }
+  }
+  for (i = 0; i < pollset_set->pollset_set_count; i++) {
+    pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+  }
+  gpr_mu_unlock(&pollset_set->mu);
+}
+
+/*******************************************************************************
+ * event engine binding
+ */
+
+static void shutdown_engine(void) {
+  fd_global_shutdown();
+  pollset_global_shutdown();
+}
+
+static const grpc_event_engine_vtable vtable = {
+    .pollset_size = sizeof(grpc_pollset),
+
+    .fd_create = fd_create,
+    .fd_wrapped_fd = fd_wrapped_fd,
+    .fd_orphan = fd_orphan,
+    .fd_shutdown = fd_shutdown,
+    .fd_notify_on_read = fd_notify_on_read,
+    .fd_notify_on_write = fd_notify_on_write,
+
+    .pollset_init = pollset_init,
+    .pollset_shutdown = pollset_shutdown,
+    .pollset_reset = pollset_reset,
+    .pollset_destroy = pollset_destroy,
+    .pollset_work = pollset_work,
+    .pollset_kick = pollset_kick,
+    .pollset_add_fd = pollset_add_fd,
+
+    .pollset_set_create = pollset_set_create,
+    .pollset_set_destroy = pollset_set_destroy,
+    .pollset_set_add_pollset = pollset_set_add_pollset,
+    .pollset_set_del_pollset = pollset_set_del_pollset,
+    .pollset_set_add_pollset_set = pollset_set_add_pollset_set,
+    .pollset_set_del_pollset_set = pollset_set_del_pollset_set,
+    .pollset_set_add_fd = pollset_set_add_fd,
+    .pollset_set_del_fd = pollset_set_del_fd,
+
+    .kick_poller = kick_poller,
+
+    .shutdown_engine = shutdown_engine,
+};
+
+const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void) {
+#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+  platform_become_multipoller = epoll_become_multipoller;
+#else
+  platform_become_multipoller = poll_become_multipoller;
+#endif
+  fd_global_init();
+  pollset_global_init();
+  return &vtable;
+}
+
+#endif
diff --git a/src/core/lib/iomgr/pollset_set_posix.h b/src/core/lib/iomgr/ev_poll_and_epoll_posix.h
index 4e6b063c6f..06d6dbf29d 100644
--- a/src/core/lib/iomgr/pollset_set_posix.h
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,15 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_IOMGR_POLLSET_SET_POSIX_H
-#define GRPC_CORE_LIB_IOMGR_POLLSET_SET_POSIX_H
+#ifndef GRPC_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H
+#define GRPC_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H
 
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/pollset_set.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 
-void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
-                             grpc_pollset_set *pollset_set, grpc_fd *fd);
-void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
-                             grpc_pollset_set *pollset_set, grpc_fd *fd);
+const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void);
 
-#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_SET_POSIX_H */
+#endif /* GRPC_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H */
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
new file mode 100644
index 0000000000..235a7df08d
--- /dev/null
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -0,0 +1,165 @@
+/*
+ *
+ * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/lib/iomgr/ev_posix.h"
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
+
+static const grpc_event_engine_vtable *g_event_engine;
+
+grpc_poll_function_type grpc_poll_function = poll;
+grpc_wakeup_fd grpc_global_wakeup_fd;
+
+void grpc_event_engine_init(void) {
+  if ((g_event_engine = grpc_init_poll_and_epoll_posix())) {
+    return;
+  }
+  gpr_log(GPR_ERROR, "No event engine could be initialized");
+  abort();
+}
+
+void grpc_event_engine_shutdown(void) { g_event_engine->shutdown_engine(); }
+
+grpc_fd *grpc_fd_create(int fd, const char *name) {
+  return g_event_engine->fd_create(fd, name);
+}
+
+int grpc_fd_wrapped_fd(grpc_fd *fd) {
+  return g_event_engine->fd_wrapped_fd(fd);
+}
+
+void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
+                    int *release_fd, const char *reason) {
+  g_event_engine->fd_orphan(exec_ctx, fd, on_done, release_fd, reason);
+}
+
+void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+  g_event_engine->fd_shutdown(exec_ctx, fd);
+}
+
+void grpc_fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                            grpc_closure *closure) {
+  g_event_engine->fd_notify_on_read(exec_ctx, fd, closure);
+}
+
+void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                             grpc_closure *closure) {
+  g_event_engine->fd_notify_on_write(exec_ctx, fd, closure);
+}
+
+size_t grpc_pollset_size(void) { return g_event_engine->pollset_size; }
+
+void grpc_pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
+  g_event_engine->pollset_init(pollset, mu);
+}
+
+void grpc_pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_closure *closure) {
+  g_event_engine->pollset_shutdown(exec_ctx, pollset, closure);
+}
+
+void grpc_pollset_reset(grpc_pollset *pollset) {
+  g_event_engine->pollset_reset(pollset);
+}
+
+void grpc_pollset_destroy(grpc_pollset *pollset) {
+  g_event_engine->pollset_destroy(pollset);
+}
+
+void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                       grpc_pollset_worker **worker, gpr_timespec now,
+                       gpr_timespec deadline) {
+  g_event_engine->pollset_work(exec_ctx, pollset, worker, now, deadline);
+}
+
+void grpc_pollset_kick(grpc_pollset *pollset,
+                       grpc_pollset_worker *specific_worker) {
+  g_event_engine->pollset_kick(pollset, specific_worker);
+}
+
+void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         struct grpc_fd *fd) {
+  g_event_engine->pollset_add_fd(exec_ctx, pollset, fd);
+}
+
+grpc_pollset_set *grpc_pollset_set_create(void) {
+  return g_event_engine->pollset_set_create();
+}
+
+void grpc_pollset_set_destroy(grpc_pollset_set *pollset_set) {
+  g_event_engine->pollset_set_destroy(pollset_set);
+}
+
+void grpc_pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset) {
+  g_event_engine->pollset_set_add_pollset(exec_ctx, pollset_set, pollset);
+}
+
+void grpc_pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset) {
+  g_event_engine->pollset_set_del_pollset(exec_ctx, pollset_set, pollset);
+}
+
+void grpc_pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item) {
+  g_event_engine->pollset_set_add_pollset_set(exec_ctx, bag, item);
+}
+
+void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item) {
+  g_event_engine->pollset_set_del_pollset_set(exec_ctx, bag, item);
+}
+
+void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd) {
+  g_event_engine->pollset_set_add_fd(exec_ctx, pollset_set, fd);
+}
+
+void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd) {
+  g_event_engine->pollset_set_del_fd(exec_ctx, pollset_set, fd);
+}
+
+void grpc_kick_poller(void) { g_event_engine->kick_poller(); }
+
+#endif  // GPR_POSIX_SOCKET
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
new file mode 100644
index 0000000000..9d27b2bcda
--- /dev/null
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -0,0 +1,158 @@
+/*
+ *
+ * Copyright 2015-2016, 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_EV_POSIX_H
+#define GRPC_CORE_LIB_IOMGR_EV_POSIX_H
+
+#include <poll.h>
+
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/pollset_set.h"
+#include "src/core/lib/iomgr/wakeup_fd_posix.h"
+
+typedef struct grpc_fd grpc_fd;
+
+typedef struct grpc_event_engine_vtable {
+  size_t pollset_size;
+
+  grpc_fd *(*fd_create)(int fd, const char *name);
+  int (*fd_wrapped_fd)(grpc_fd *fd);
+  void (*fd_orphan)(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
+                    int *release_fd, const char *reason);
+  void (*fd_shutdown)(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
+  void (*fd_notify_on_read)(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                            grpc_closure *closure);
+  void (*fd_notify_on_write)(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                             grpc_closure *closure);
+
+  void (*pollset_init)(grpc_pollset *pollset, gpr_mu **mu);
+  void (*pollset_shutdown)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_closure *closure);
+  void (*pollset_reset)(grpc_pollset *pollset);
+  void (*pollset_destroy)(grpc_pollset *pollset);
+  void (*pollset_work)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                       grpc_pollset_worker **worker, gpr_timespec now,
+                       gpr_timespec deadline);
+  void (*pollset_kick)(grpc_pollset *pollset,
+                       grpc_pollset_worker *specific_worker);
+  void (*pollset_add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         struct grpc_fd *fd);
+
+  grpc_pollset_set *(*pollset_set_create)(void);
+  void (*pollset_set_destroy)(grpc_pollset_set *pollset_set);
+  void (*pollset_set_add_pollset)(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset);
+  void (*pollset_set_del_pollset)(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset_set *pollset_set,
+                                  grpc_pollset *pollset);
+  void (*pollset_set_add_pollset_set)(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item);
+  void (*pollset_set_del_pollset_set)(grpc_exec_ctx *exec_ctx,
+                                      grpc_pollset_set *bag,
+                                      grpc_pollset_set *item);
+  void (*pollset_set_add_fd)(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd);
+  void (*pollset_set_del_fd)(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd);
+
+  void (*kick_poller)(void);
+
+  void (*shutdown_engine)(void);
+} grpc_event_engine_vtable;
+
+void grpc_event_engine_init(void);
+void grpc_event_engine_shutdown(void);
+
+/* Create a wrapped file descriptor.
+   Requires fd is a non-blocking file descriptor.
+   This takes ownership of closing fd. */
+grpc_fd *grpc_fd_create(int fd, const char *name);
+
+/* Return the wrapped fd, or -1 if it has been released or closed. */
+int grpc_fd_wrapped_fd(grpc_fd *fd);
+
+/* Releases fd to be asynchronously destroyed.
+   on_done is called when the underlying file descriptor is definitely close()d.
+   If on_done is NULL, no callback will be made.
+   If release_fd is not NULL, it's set to fd and fd will not be closed.
+   Requires: *fd initialized; no outstanding notify_on_read or
+   notify_on_write.
+   MUST NOT be called with a pollset lock taken */
+void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
+                    int *release_fd, const char *reason);
+
+/* Cause any current callbacks to error out with GRPC_CALLBACK_CANCELLED. */
+void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
+
+/* Register read interest, causing read_cb to be called once when fd becomes
+   readable, on deadline specified by deadline, or on shutdown triggered by
+   grpc_fd_shutdown.
+   read_cb will be called with read_cb_arg when *fd becomes readable.
+   read_cb is Called with status of GRPC_CALLBACK_SUCCESS if readable,
+   GRPC_CALLBACK_TIMED_OUT if the call timed out,
+   and CANCELLED if the call was cancelled.
+
+   Requires:This method must not be called before the read_cb for any previous
+   call runs. Edge triggered events are used whenever they are supported by the
+   underlying platform. This means that users must drain fd in read_cb before
+   calling notify_on_read again. Users are also expected to handle spurious
+   events, i.e read_cb is called while nothing can be readable from fd  */
+void grpc_fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                            grpc_closure *closure);
+
+/* Exactly the same semantics as above, except based on writable events.  */
+void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+                             grpc_closure *closure);
+
+/* pollset_posix functions */
+
+/* Add an fd to a pollset */
+void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         struct grpc_fd *fd);
+
+/* pollset_set_posix functions */
+
+void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd);
+void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
+                             grpc_pollset_set *pollset_set, grpc_fd *fd);
+
+/* override to allow tests to hook poll() usage */
+typedef int (*grpc_poll_function_type)(struct pollfd *, nfds_t, int);
+extern grpc_poll_function_type grpc_poll_function;
+extern grpc_wakeup_fd grpc_global_wakeup_fd;
+
+#endif /* GRPC_CORE_LIB_IOMGR_EV_POSIX_H */
diff --git a/src/core/lib/iomgr/exec_ctx.c b/src/core/lib/iomgr/exec_ctx.c
index 1ed6da623a..2146c7dd1f 100644
--- a/src/core/lib/iomgr/exec_ctx.c
+++ b/src/core/lib/iomgr/exec_ctx.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index e62ea2dedf..e09ef02400 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/executor.c b/src/core/lib/iomgr/executor.c
index 42a9db3cbb..36e22e4271 100644
--- a/src/core/lib/iomgr/executor.c
+++ b/src/core/lib/iomgr/executor.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/executor.h b/src/core/lib/iomgr/executor.h
index f1871416a0..b7e6f51aa5 100644
--- a/src/core/lib/iomgr/executor.h
+++ b/src/core/lib/iomgr/executor.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/fd_posix.c b/src/core/lib/iomgr/fd_posix.c
deleted file mode 100644
index 72c924bdcb..0000000000
--- a/src/core/lib/iomgr/fd_posix.c
+++ /dev/null
@@ -1,454 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_SOCKET
-
-#include "src/core/lib/iomgr/fd_posix.h"
-
-#include <assert.h>
-#include <sys/socket.h>
-#include <unistd.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/string_util.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/pollset_posix.h"
-
-#define CLOSURE_NOT_READY ((grpc_closure *)0)
-#define CLOSURE_READY ((grpc_closure *)1)
-
-/* We need to keep a freelist not because of any concerns of malloc performance
- * but instead so that implementations with multiple threads in (for example)
- * epoll_wait deal with the race between pollset removal and incoming poll
- * notifications.
- *
- * The problem is that the poller ultimately holds a reference to this
- * object, so it is very difficult to know when is safe to free it, at least
- * without some expensive synchronization.
- *
- * If we keep the object freelisted, in the worst case losing this race just
- * becomes a spurious read notification on a reused fd.
- */
-/* TODO(klempner): We could use some form of polling generation count to know
- * when these are safe to free. */
-/* TODO(klempner): Consider disabling freelisting if we don't have multiple
- * threads in poll on the same fd */
-/* TODO(klempner): Batch these allocations to reduce fragmentation */
-static grpc_fd *fd_freelist = NULL;
-static gpr_mu fd_freelist_mu;
-
-static void freelist_fd(grpc_fd *fd) {
-  gpr_mu_lock(&fd_freelist_mu);
-  fd->freelist_next = fd_freelist;
-  fd_freelist = fd;
-  grpc_iomgr_unregister_object(&fd->iomgr_object);
-  gpr_mu_unlock(&fd_freelist_mu);
-}
-
-static grpc_fd *alloc_fd(int fd) {
-  grpc_fd *r = NULL;
-  gpr_mu_lock(&fd_freelist_mu);
-  if (fd_freelist != NULL) {
-    r = fd_freelist;
-    fd_freelist = fd_freelist->freelist_next;
-  }
-  gpr_mu_unlock(&fd_freelist_mu);
-  if (r == NULL) {
-    r = gpr_malloc(sizeof(grpc_fd));
-    gpr_mu_init(&r->mu);
-  }
-
-  gpr_mu_lock(&r->mu);
-  r->shutdown = 0;
-  r->read_closure = CLOSURE_NOT_READY;
-  r->write_closure = CLOSURE_NOT_READY;
-  r->fd = fd;
-  r->inactive_watcher_root.next = r->inactive_watcher_root.prev =
-      &r->inactive_watcher_root;
-  r->freelist_next = NULL;
-  r->read_watcher = r->write_watcher = NULL;
-  r->on_done_closure = NULL;
-  r->closed = 0;
-  r->released = 0;
-  gpr_atm_rel_store(&r->refst, 1);
-  gpr_mu_unlock(&r->mu);
-
-  return r;
-}
-
-static void destroy(grpc_fd *fd) {
-  gpr_mu_destroy(&fd->mu);
-  gpr_free(fd);
-}
-
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-#define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__)
-#define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
-static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file,
-                   int line) {
-  gpr_log(GPR_DEBUG, "FD %d %p   ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
-          gpr_atm_no_barrier_load(&fd->refst),
-          gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
-#else
-#define REF_BY(fd, n, reason) ref_by(fd, n)
-#define UNREF_BY(fd, n, reason) unref_by(fd, n)
-static void ref_by(grpc_fd *fd, int n) {
-#endif
-  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0);
-}
-
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file,
-                     int line) {
-  gpr_atm old;
-  gpr_log(GPR_DEBUG, "FD %d %p unref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
-          gpr_atm_no_barrier_load(&fd->refst),
-          gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line);
-#else
-static void unref_by(grpc_fd *fd, int n) {
-  gpr_atm old;
-#endif
-  old = gpr_atm_full_fetch_add(&fd->refst, -n);
-  if (old == n) {
-    freelist_fd(fd);
-  } else {
-    GPR_ASSERT(old > n);
-  }
-}
-
-void grpc_fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); }
-
-void grpc_fd_global_shutdown(void) {
-  gpr_mu_lock(&fd_freelist_mu);
-  gpr_mu_unlock(&fd_freelist_mu);
-  while (fd_freelist != NULL) {
-    grpc_fd *fd = fd_freelist;
-    fd_freelist = fd_freelist->freelist_next;
-    destroy(fd);
-  }
-  gpr_mu_destroy(&fd_freelist_mu);
-}
-
-grpc_fd *grpc_fd_create(int fd, const char *name) {
-  grpc_fd *r = alloc_fd(fd);
-  char *name2;
-  gpr_asprintf(&name2, "%s fd=%d", name, fd);
-  grpc_iomgr_register_object(&r->iomgr_object, name2);
-  gpr_free(name2);
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-  gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, r, name);
-#endif
-  return r;
-}
-
-int grpc_fd_is_orphaned(grpc_fd *fd) {
-  return (gpr_atm_acq_load(&fd->refst) & 1) == 0;
-}
-
-static void pollset_kick_locked(grpc_fd_watcher *watcher) {
-  gpr_mu_lock(&watcher->pollset->mu);
-  GPR_ASSERT(watcher->worker);
-  grpc_pollset_kick_ext(watcher->pollset, watcher->worker,
-                        GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP);
-  gpr_mu_unlock(&watcher->pollset->mu);
-}
-
-static void maybe_wake_one_watcher_locked(grpc_fd *fd) {
-  if (fd->inactive_watcher_root.next != &fd->inactive_watcher_root) {
-    pollset_kick_locked(fd->inactive_watcher_root.next);
-  } else if (fd->read_watcher) {
-    pollset_kick_locked(fd->read_watcher);
-  } else if (fd->write_watcher) {
-    pollset_kick_locked(fd->write_watcher);
-  }
-}
-
-static void wake_all_watchers_locked(grpc_fd *fd) {
-  grpc_fd_watcher *watcher;
-  for (watcher = fd->inactive_watcher_root.next;
-       watcher != &fd->inactive_watcher_root; watcher = watcher->next) {
-    pollset_kick_locked(watcher);
-  }
-  if (fd->read_watcher) {
-    pollset_kick_locked(fd->read_watcher);
-  }
-  if (fd->write_watcher && fd->write_watcher != fd->read_watcher) {
-    pollset_kick_locked(fd->write_watcher);
-  }
-}
-
-static int has_watchers(grpc_fd *fd) {
-  return fd->read_watcher != NULL || fd->write_watcher != NULL ||
-         fd->inactive_watcher_root.next != &fd->inactive_watcher_root;
-}
-
-static void close_fd_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  fd->closed = 1;
-  if (!fd->released) {
-    close(fd->fd);
-  } else {
-    grpc_remove_fd_from_all_epoll_sets(fd->fd);
-  }
-  grpc_exec_ctx_enqueue(exec_ctx, fd->on_done_closure, true, NULL);
-}
-
-int grpc_fd_wrapped_fd(grpc_fd *fd) {
-  if (fd->released || fd->closed) {
-    return -1;
-  } else {
-    return fd->fd;
-  }
-}
-
-void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
-                    int *release_fd, const char *reason) {
-  fd->on_done_closure = on_done;
-  fd->released = release_fd != NULL;
-  if (!fd->released) {
-    shutdown(fd->fd, SHUT_RDWR);
-  } else {
-    *release_fd = fd->fd;
-  }
-  gpr_mu_lock(&fd->mu);
-  REF_BY(fd, 1, reason); /* remove active status, but keep referenced */
-  if (!has_watchers(fd)) {
-    close_fd_locked(exec_ctx, fd);
-  } else {
-    wake_all_watchers_locked(fd);
-  }
-  gpr_mu_unlock(&fd->mu);
-  UNREF_BY(fd, 2, reason); /* drop the reference */
-}
-
-/* increment refcount by two to avoid changing the orphan bit */
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-void grpc_fd_ref(grpc_fd *fd, const char *reason, const char *file, int line) {
-  ref_by(fd, 2, reason, file, line);
-}
-
-void grpc_fd_unref(grpc_fd *fd, const char *reason, const char *file,
-                   int line) {
-  unref_by(fd, 2, reason, file, line);
-}
-#else
-void grpc_fd_ref(grpc_fd *fd) { ref_by(fd, 2); }
-
-void grpc_fd_unref(grpc_fd *fd) { unref_by(fd, 2); }
-#endif
-
-static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                             grpc_closure **st, grpc_closure *closure) {
-  if (*st == CLOSURE_NOT_READY) {
-    /* not ready ==> switch to a waiting state by setting the closure */
-    *st = closure;
-  } else if (*st == CLOSURE_READY) {
-    /* already ready ==> queue the closure to run immediately */
-    *st = CLOSURE_NOT_READY;
-    grpc_exec_ctx_enqueue(exec_ctx, closure, !fd->shutdown, NULL);
-    maybe_wake_one_watcher_locked(fd);
-  } else {
-    /* upcallptr was set to a different closure.  This is an error! */
-    gpr_log(GPR_ERROR,
-            "User called a notify_on function with a previous callback still "
-            "pending");
-    abort();
-  }
-}
-
-/* returns 1 if state becomes not ready */
-static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                            grpc_closure **st) {
-  if (*st == CLOSURE_READY) {
-    /* duplicate ready ==> ignore */
-    return 0;
-  } else if (*st == CLOSURE_NOT_READY) {
-    /* not ready, and not waiting ==> flag ready */
-    *st = CLOSURE_READY;
-    return 0;
-  } else {
-    /* waiting ==> queue closure */
-    grpc_exec_ctx_enqueue(exec_ctx, *st, !fd->shutdown, NULL);
-    *st = CLOSURE_NOT_READY;
-    return 1;
-  }
-}
-
-static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure **st) {
-  /* only one set_ready can be active at once (but there may be a racing
-     notify_on) */
-  gpr_mu_lock(&fd->mu);
-  set_ready_locked(exec_ctx, fd, st);
-  gpr_mu_unlock(&fd->mu);
-}
-
-void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  gpr_mu_lock(&fd->mu);
-  GPR_ASSERT(!fd->shutdown);
-  fd->shutdown = 1;
-  set_ready_locked(exec_ctx, fd, &fd->read_closure);
-  set_ready_locked(exec_ctx, fd, &fd->write_closure);
-  gpr_mu_unlock(&fd->mu);
-}
-
-void grpc_fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                            grpc_closure *closure) {
-  gpr_mu_lock(&fd->mu);
-  notify_on_locked(exec_ctx, fd, &fd->read_closure, closure);
-  gpr_mu_unlock(&fd->mu);
-}
-
-void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                             grpc_closure *closure) {
-  gpr_mu_lock(&fd->mu);
-  notify_on_locked(exec_ctx, fd, &fd->write_closure, closure);
-  gpr_mu_unlock(&fd->mu);
-}
-
-uint32_t grpc_fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
-                            grpc_pollset_worker *worker, uint32_t read_mask,
-                            uint32_t write_mask, grpc_fd_watcher *watcher) {
-  uint32_t mask = 0;
-  grpc_closure *cur;
-  int requested;
-  /* keep track of pollers that have requested our events, in case they change
-   */
-  GRPC_FD_REF(fd, "poll");
-
-  gpr_mu_lock(&fd->mu);
-
-  /* if we are shutdown, then don't add to the watcher set */
-  if (fd->shutdown) {
-    watcher->fd = NULL;
-    watcher->pollset = NULL;
-    watcher->worker = NULL;
-    gpr_mu_unlock(&fd->mu);
-    GRPC_FD_UNREF(fd, "poll");
-    return 0;
-  }
-
-  /* if there is nobody polling for read, but we need to, then start doing so */
-  cur = fd->read_closure;
-  requested = cur != CLOSURE_READY;
-  if (read_mask && fd->read_watcher == NULL && requested) {
-    fd->read_watcher = watcher;
-    mask |= read_mask;
-  }
-  /* if there is nobody polling for write, but we need to, then start doing so
-   */
-  cur = fd->write_closure;
-  requested = cur != CLOSURE_READY;
-  if (write_mask && fd->write_watcher == NULL && requested) {
-    fd->write_watcher = watcher;
-    mask |= write_mask;
-  }
-  /* if not polling, remember this watcher in case we need someone to later */
-  if (mask == 0 && worker != NULL) {
-    watcher->next = &fd->inactive_watcher_root;
-    watcher->prev = watcher->next->prev;
-    watcher->next->prev = watcher->prev->next = watcher;
-  }
-  watcher->pollset = pollset;
-  watcher->worker = worker;
-  watcher->fd = fd;
-  gpr_mu_unlock(&fd->mu);
-
-  return mask;
-}
-
-void grpc_fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *watcher,
-                      int got_read, int got_write) {
-  int was_polling = 0;
-  int kick = 0;
-  grpc_fd *fd = watcher->fd;
-
-  if (fd == NULL) {
-    return;
-  }
-
-  gpr_mu_lock(&fd->mu);
-
-  if (watcher == fd->read_watcher) {
-    /* remove read watcher, kick if we still need a read */
-    was_polling = 1;
-    if (!got_read) {
-      kick = 1;
-    }
-    fd->read_watcher = NULL;
-  }
-  if (watcher == fd->write_watcher) {
-    /* remove write watcher, kick if we still need a write */
-    was_polling = 1;
-    if (!got_write) {
-      kick = 1;
-    }
-    fd->write_watcher = NULL;
-  }
-  if (!was_polling && watcher->worker != NULL) {
-    /* remove from inactive list */
-    watcher->next->prev = watcher->prev;
-    watcher->prev->next = watcher->next;
-  }
-  if (got_read) {
-    if (set_ready_locked(exec_ctx, fd, &fd->read_closure)) {
-      kick = 1;
-    }
-  }
-  if (got_write) {
-    if (set_ready_locked(exec_ctx, fd, &fd->write_closure)) {
-      kick = 1;
-    }
-  }
-  if (kick) {
-    maybe_wake_one_watcher_locked(fd);
-  }
-  if (grpc_fd_is_orphaned(fd) && !has_watchers(fd) && !fd->closed) {
-    close_fd_locked(exec_ctx, fd);
-  }
-  gpr_mu_unlock(&fd->mu);
-
-  GRPC_FD_UNREF(fd, "poll");
-}
-
-void grpc_fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  set_ready(exec_ctx, fd, &fd->read_closure);
-}
-
-void grpc_fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  set_ready(exec_ctx, fd, &fd->write_closure);
-}
-
-#endif
diff --git a/src/core/lib/iomgr/fd_posix.h b/src/core/lib/iomgr/fd_posix.h
deleted file mode 100644
index 69d09ef5e3..0000000000
--- a/src/core/lib/iomgr/fd_posix.h
+++ /dev/null
@@ -1,192 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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_FD_POSIX_H
-#define GRPC_CORE_LIB_IOMGR_FD_POSIX_H
-
-#include <grpc/support/atm.h>
-#include <grpc/support/sync.h>
-#include <grpc/support/time.h>
-#include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/pollset.h"
-
-typedef struct grpc_fd grpc_fd;
-
-typedef struct grpc_fd_watcher {
-  struct grpc_fd_watcher *next;
-  struct grpc_fd_watcher *prev;
-  grpc_pollset *pollset;
-  grpc_pollset_worker *worker;
-  grpc_fd *fd;
-} grpc_fd_watcher;
-
-struct grpc_fd {
-  int fd;
-  /* refst format:
-     bit0:   1=active/0=orphaned
-     bit1-n: refcount
-     meaning that mostly we ref by two to avoid altering the orphaned bit,
-     and just unref by 1 when we're ready to flag the object as orphaned */
-  gpr_atm refst;
-
-  gpr_mu mu;
-  int shutdown;
-  int closed;
-  int released;
-
-  /* The watcher list.
-
-     The following watcher related fields are protected by watcher_mu.
-
-     An fd_watcher is an ephemeral object created when an fd wants to
-     begin polling, and destroyed after the poll.
-
-     It denotes the fd's interest in whether to read poll or write poll
-     or both or neither on this fd.
-
-     If a watcher is asked to poll for reads or writes, the read_watcher
-     or write_watcher fields are set respectively. A watcher may be asked
-     to poll for both, in which case both fields will be set.
-
-     read_watcher and write_watcher may be NULL if no watcher has been
-     asked to poll for reads or writes.
-
-     If an fd_watcher is not asked to poll for reads or writes, it's added
-     to a linked list of inactive watchers, rooted at inactive_watcher_root.
-     If at a later time there becomes need of a poller to poll, one of
-     the inactive pollers may be kicked out of their poll loops to take
-     that responsibility. */
-  grpc_fd_watcher inactive_watcher_root;
-  grpc_fd_watcher *read_watcher;
-  grpc_fd_watcher *write_watcher;
-
-  grpc_closure *read_closure;
-  grpc_closure *write_closure;
-
-  struct grpc_fd *freelist_next;
-
-  grpc_closure *on_done_closure;
-
-  grpc_iomgr_object iomgr_object;
-};
-
-/* Create a wrapped file descriptor.
-   Requires fd is a non-blocking file descriptor.
-   This takes ownership of closing fd. */
-grpc_fd *grpc_fd_create(int fd, const char *name);
-
-/* Return the wrapped fd, or -1 if it has been released or closed. */
-int grpc_fd_wrapped_fd(grpc_fd *fd);
-
-/* Releases fd to be asynchronously destroyed.
-   on_done is called when the underlying file descriptor is definitely close()d.
-   If on_done is NULL, no callback will be made.
-   If release_fd is not NULL, it's set to fd and fd will not be closed.
-   Requires: *fd initialized; no outstanding notify_on_read or
-   notify_on_write.
-   MUST NOT be called with a pollset lock taken */
-void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done,
-                    int *release_fd, const char *reason);
-
-/* Begin polling on an fd.
-   Registers that the given pollset is interested in this fd - so that if read
-   or writability interest changes, the pollset can be kicked to pick up that
-   new interest.
-   Return value is:
-     (fd_needs_read? read_mask : 0) | (fd_needs_write? write_mask : 0)
-   i.e. a combination of read_mask and write_mask determined by the fd's current
-   interest in said events.
-   Polling strategies that do not need to alter their behavior depending on the
-   fd's current interest (such as epoll) do not need to call this function.
-   MUST NOT be called with a pollset lock taken */
-uint32_t grpc_fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
-                            grpc_pollset_worker *worker, uint32_t read_mask,
-                            uint32_t write_mask, grpc_fd_watcher *rec);
-/* Complete polling previously started with grpc_fd_begin_poll
-   MUST NOT be called with a pollset lock taken
-   if got_read or got_write are 1, also does the become_{readable,writable} as
-   appropriate. */
-void grpc_fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *rec,
-                      int got_read, int got_write);
-
-/* Return 1 if this fd is orphaned, 0 otherwise */
-int grpc_fd_is_orphaned(grpc_fd *fd);
-
-/* Cause any current callbacks to error out with GRPC_CALLBACK_CANCELLED. */
-void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
-
-/* Register read interest, causing read_cb to be called once when fd becomes
-   readable, on deadline specified by deadline, or on shutdown triggered by
-   grpc_fd_shutdown.
-   read_cb will be called with read_cb_arg when *fd becomes readable.
-   read_cb is Called with status of GRPC_CALLBACK_SUCCESS if readable,
-   GRPC_CALLBACK_TIMED_OUT if the call timed out,
-   and CANCELLED if the call was cancelled.
-
-   Requires:This method must not be called before the read_cb for any previous
-   call runs. Edge triggered events are used whenever they are supported by the
-   underlying platform. This means that users must drain fd in read_cb before
-   calling notify_on_read again. Users are also expected to handle spurious
-   events, i.e read_cb is called while nothing can be readable from fd  */
-void grpc_fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                            grpc_closure *closure);
-
-/* Exactly the same semantics as above, except based on writable events.  */
-void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                             grpc_closure *closure);
-
-/* Notification from the poller to an fd that it has become readable or
-   writable.
-   If allow_synchronous_callback is 1, allow running the fd callback inline
-   in this callstack, otherwise register an asynchronous callback and return */
-void grpc_fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
-void grpc_fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd);
-
-/* Reference counting for fds */
-/*#define GRPC_FD_REF_COUNT_DEBUG*/
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-void grpc_fd_ref(grpc_fd *fd, const char *reason, const char *file, int line);
-void grpc_fd_unref(grpc_fd *fd, const char *reason, const char *file, int line);
-#define GRPC_FD_REF(fd, reason) grpc_fd_ref(fd, reason, __FILE__, __LINE__)
-#define GRPC_FD_UNREF(fd, reason) grpc_fd_unref(fd, reason, __FILE__, __LINE__)
-#else
-void grpc_fd_ref(grpc_fd *fd);
-void grpc_fd_unref(grpc_fd *fd);
-#define GRPC_FD_REF(fd, reason) grpc_fd_ref(fd)
-#define GRPC_FD_UNREF(fd, reason) grpc_fd_unref(fd)
-#endif
-
-void grpc_fd_global_init(void);
-void grpc_fd_global_shutdown(void);
-
-#endif /* GRPC_CORE_LIB_IOMGR_FD_POSIX_H */
diff --git a/src/core/lib/iomgr/iocp_windows.c b/src/core/lib/iomgr/iocp_windows.c
index 682a32c0da..d46558ab1b 100644
--- a/src/core/lib/iomgr/iocp_windows.c
+++ b/src/core/lib/iomgr/iocp_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/iocp_windows.h b/src/core/lib/iomgr/iocp_windows.h
index 856c837fb4..ae210fa7d7 100644
--- a/src/core/lib/iomgr/iocp_windows.h
+++ b/src/core/lib/iomgr/iocp_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/iomgr.c b/src/core/lib/iomgr/iomgr.c
index bb544c8280..146663984d 100644
--- a/src/core/lib/iomgr/iomgr.c
+++ b/src/core/lib/iomgr/iomgr.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -63,7 +63,6 @@ void grpc_iomgr_init(void) {
   g_root_object.next = g_root_object.prev = &g_root_object;
   g_root_object.name = "root";
   grpc_iomgr_platform_init();
-  grpc_pollset_global_init();
 }
 
 static size_t count_objects(void) {
@@ -138,7 +137,6 @@ void grpc_iomgr_shutdown(void) {
   gpr_mu_lock(&g_mu);
   gpr_mu_unlock(&g_mu);
 
-  grpc_pollset_global_shutdown();
   grpc_iomgr_platform_shutdown();
   grpc_exec_ctx_global_shutdown();
   gpr_mu_destroy(&g_mu);
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index babf0a85b7..6c82de78ac 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/iomgr_internal.h b/src/core/lib/iomgr/iomgr_internal.h
index 0963630c61..805be1f1e4 100644
--- a/src/core/lib/iomgr/iomgr_internal.h
+++ b/src/core/lib/iomgr/iomgr_internal.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,7 +36,6 @@
 
 #include <stdbool.h>
 
-#include <grpc/support/sync.h>
 #include "src/core/lib/iomgr/iomgr.h"
 
 typedef struct grpc_iomgr_object {
@@ -45,9 +44,6 @@ typedef struct grpc_iomgr_object {
   struct grpc_iomgr_object *prev;
 } grpc_iomgr_object;
 
-void grpc_pollset_global_init(void);
-void grpc_pollset_global_shutdown(void);
-
 void grpc_iomgr_register_object(grpc_iomgr_object *obj, const char *name);
 void grpc_iomgr_unregister_object(grpc_iomgr_object *obj);
 
diff --git a/src/core/lib/iomgr/iomgr_posix.c b/src/core/lib/iomgr/iomgr_posix.c
index e4990f7bce..016c501f75 100644
--- a/src/core/lib/iomgr/iomgr_posix.c
+++ b/src/core/lib/iomgr/iomgr_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,17 +36,17 @@
 #ifdef GPR_POSIX_SOCKET
 
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/iomgr/fd_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_posix.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
 
 void grpc_iomgr_platform_init(void) {
-  grpc_fd_global_init();
+  grpc_event_engine_init();
   grpc_register_tracer("tcp", &grpc_tcp_trace);
 }
 
 void grpc_iomgr_platform_flush(void) {}
 
-void grpc_iomgr_platform_shutdown(void) { grpc_fd_global_shutdown(); }
+void grpc_iomgr_platform_shutdown(void) { grpc_event_engine_shutdown(); }
 
 #endif /* GRPC_POSIX_SOCKET */
diff --git a/src/core/lib/iomgr/iomgr_posix.h b/src/core/lib/iomgr/iomgr_posix.h
index 6a8996e403..d5eade962a 100644
--- a/src/core/lib/iomgr/iomgr_posix.h
+++ b/src/core/lib/iomgr/iomgr_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/iomgr_windows.c b/src/core/lib/iomgr/iomgr_windows.c
index af7e616394..398517fc75 100644
--- a/src/core/lib/iomgr/iomgr_windows.c
+++ b/src/core/lib/iomgr/iomgr_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,6 +41,7 @@
 
 #include "src/core/lib/iomgr/iocp_windows.h"
 #include "src/core/lib/iomgr/iomgr.h"
+#include "src/core/lib/iomgr/pollset_windows.h"
 #include "src/core/lib/iomgr/socket_windows.h"
 
 /* Windows' io manager is going to be fully designed using IO completion
@@ -61,11 +62,13 @@ static void winsock_shutdown(void) {
 void grpc_iomgr_platform_init(void) {
   winsock_init();
   grpc_iocp_init();
+  grpc_pollset_global_init();
 }
 
 void grpc_iomgr_platform_flush(void) { grpc_iocp_flush(); }
 
 void grpc_iomgr_platform_shutdown(void) {
+  grpc_pollset_global_shutdown();
   grpc_iocp_shutdown();
   winsock_shutdown();
 }
diff --git a/src/core/lib/iomgr/pollset.h b/src/core/lib/iomgr/pollset.h
index 6156124862..c40a474877 100644
--- a/src/core/lib/iomgr/pollset.h
+++ b/src/core/lib/iomgr/pollset.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/pollset_multipoller_with_epoll.c b/src/core/lib/iomgr/pollset_multipoller_with_epoll.c
deleted file mode 100644
index fa1b0d2d84..0000000000
--- a/src/core/lib/iomgr/pollset_multipoller_with_epoll.c
+++ /dev/null
@@ -1,324 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
-
-#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
-
-#include <errno.h>
-#include <poll.h>
-#include <string.h>
-#include <sys/epoll.h>
-#include <unistd.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/useful.h>
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
-#include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
-
-struct epoll_fd_list {
-  int *epoll_fds;
-  size_t count;
-  size_t capacity;
-};
-
-static struct epoll_fd_list epoll_fd_global_list;
-static gpr_once init_epoll_fd_list_mu = GPR_ONCE_INIT;
-static gpr_mu epoll_fd_list_mu;
-
-static void init_mu(void) { gpr_mu_init(&epoll_fd_list_mu); }
-
-static void add_epoll_fd_to_global_list(int epoll_fd) {
-  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
-
-  gpr_mu_lock(&epoll_fd_list_mu);
-  if (epoll_fd_global_list.count == epoll_fd_global_list.capacity) {
-    epoll_fd_global_list.capacity =
-        GPR_MAX((size_t)8, epoll_fd_global_list.capacity * 2);
-    epoll_fd_global_list.epoll_fds =
-        gpr_realloc(epoll_fd_global_list.epoll_fds,
-                    epoll_fd_global_list.capacity * sizeof(int));
-  }
-  epoll_fd_global_list.epoll_fds[epoll_fd_global_list.count++] = epoll_fd;
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-static void remove_epoll_fd_from_global_list(int epoll_fd) {
-  gpr_mu_lock(&epoll_fd_list_mu);
-  GPR_ASSERT(epoll_fd_global_list.count > 0);
-  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
-    if (epoll_fd == epoll_fd_global_list.epoll_fds[i]) {
-      epoll_fd_global_list.epoll_fds[i] =
-          epoll_fd_global_list.epoll_fds[--(epoll_fd_global_list.count)];
-      break;
-    }
-  }
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-void grpc_remove_fd_from_all_epoll_sets(int fd) {
-  int err;
-  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
-  gpr_mu_lock(&epoll_fd_list_mu);
-  if (epoll_fd_global_list.count == 0) {
-    gpr_mu_unlock(&epoll_fd_list_mu);
-    return;
-  }
-  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
-    err = epoll_ctl(epoll_fd_global_list.epoll_fds[i], EPOLL_CTL_DEL, fd, NULL);
-    if (err < 0 && errno != ENOENT) {
-      gpr_log(GPR_ERROR, "epoll_ctl del for %d failed: %s", fd,
-              strerror(errno));
-    }
-  }
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-typedef struct {
-  grpc_pollset *pollset;
-  grpc_fd *fd;
-  grpc_closure closure;
-} delayed_add;
-
-typedef struct { int epoll_fd; } pollset_hdr;
-
-static void finally_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                           grpc_fd *fd) {
-  pollset_hdr *h = pollset->data.ptr;
-  struct epoll_event ev;
-  int err;
-  grpc_fd_watcher watcher;
-
-  /* We pretend to be polling whilst adding an fd to keep the fd from being
-     closed during the add. This may result in a spurious wakeup being assigned
-     to this pollset whilst adding, but that should be benign. */
-  GPR_ASSERT(grpc_fd_begin_poll(fd, pollset, NULL, 0, 0, &watcher) == 0);
-  if (watcher.fd != NULL) {
-    ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
-    ev.data.ptr = fd;
-    err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev);
-    if (err < 0) {
-      /* FDs may be added to a pollset multiple times, so EEXIST is normal. */
-      if (errno != EEXIST) {
-        gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd,
-                strerror(errno));
-      }
-    }
-  }
-  grpc_fd_end_poll(exec_ctx, &watcher, 0, 0);
-}
-
-static void perform_delayed_add(grpc_exec_ctx *exec_ctx, void *arg,
-                                bool iomgr_status) {
-  delayed_add *da = arg;
-
-  if (!grpc_fd_is_orphaned(da->fd)) {
-    finally_add_fd(exec_ctx, da->pollset, da->fd);
-  }
-
-  gpr_mu_lock(&da->pollset->mu);
-  da->pollset->in_flight_cbs--;
-  if (da->pollset->shutting_down) {
-    /* We don't care about this pollset anymore. */
-    if (da->pollset->in_flight_cbs == 0 && !da->pollset->called_shutdown) {
-      da->pollset->called_shutdown = 1;
-      grpc_exec_ctx_enqueue(exec_ctx, da->pollset->shutdown_done, true, NULL);
-    }
-  }
-  gpr_mu_unlock(&da->pollset->mu);
-
-  GRPC_FD_UNREF(da->fd, "delayed_add");
-
-  gpr_free(da);
-}
-
-static void multipoll_with_epoll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
-                                                grpc_pollset *pollset,
-                                                grpc_fd *fd,
-                                                int and_unlock_pollset) {
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-    finally_add_fd(exec_ctx, pollset, fd);
-  } else {
-    delayed_add *da = gpr_malloc(sizeof(*da));
-    da->pollset = pollset;
-    da->fd = fd;
-    GRPC_FD_REF(fd, "delayed_add");
-    grpc_closure_init(&da->closure, perform_delayed_add, da);
-    pollset->in_flight_cbs++;
-    grpc_exec_ctx_enqueue(exec_ctx, &da->closure, true, NULL);
-  }
-}
-
-/* TODO(klempner): We probably want to turn this down a bit */
-#define GRPC_EPOLL_MAX_EVENTS 1000
-
-static void multipoll_with_epoll_pollset_maybe_work_and_unlock(
-    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
-    gpr_timespec deadline, gpr_timespec now) {
-  struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
-  int ep_rv;
-  int poll_rv;
-  pollset_hdr *h = pollset->data.ptr;
-  int timeout_ms;
-  struct pollfd pfds[2];
-
-  /* If you want to ignore epoll's ability to sanely handle parallel pollers,
-   * for a more apples-to-apples performance comparison with poll, add a
-   * if (pollset->counter != 0) { return 0; }
-   * here.
-   */
-
-  gpr_mu_unlock(&pollset->mu);
-
-  timeout_ms = grpc_poll_deadline_to_millis_timeout(deadline, now);
-
-  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfds[0].events = POLLIN;
-  pfds[0].revents = 0;
-  pfds[1].fd = h->epoll_fd;
-  pfds[1].events = POLLIN;
-  pfds[1].revents = 0;
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  GPR_TIMER_BEGIN("poll", 0);
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  poll_rv = grpc_poll_function(pfds, 2, timeout_ms);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-  GPR_TIMER_END("poll", 0);
-
-  if (poll_rv < 0) {
-    if (errno != EINTR) {
-      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
-    }
-  } else if (poll_rv == 0) {
-    /* do nothing */
-  } else {
-    if (pfds[0].revents) {
-      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
-    }
-    if (pfds[1].revents) {
-      do {
-        /* The following epoll_wait never blocks; it has a timeout of 0 */
-        ep_rv = epoll_wait(h->epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
-        if (ep_rv < 0) {
-          if (errno != EINTR) {
-            gpr_log(GPR_ERROR, "epoll_wait() failed: %s", strerror(errno));
-          }
-        } else {
-          int i;
-          for (i = 0; i < ep_rv; ++i) {
-            grpc_fd *fd = ep_ev[i].data.ptr;
-            /* TODO(klempner): We might want to consider making err and pri
-             * separate events */
-            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 (fd == NULL) {
-              grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
-            } else {
-              if (read_ev || cancel) {
-                grpc_fd_become_readable(exec_ctx, fd);
-              }
-              if (write_ev || cancel) {
-                grpc_fd_become_writable(exec_ctx, fd);
-              }
-            }
-          }
-        }
-      } while (ep_rv == GRPC_EPOLL_MAX_EVENTS);
-    }
-  }
-}
-
-static void multipoll_with_epoll_pollset_finish_shutdown(
-    grpc_pollset *pollset) {}
-
-static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset) {
-  pollset_hdr *h = pollset->data.ptr;
-  close(h->epoll_fd);
-  remove_epoll_fd_from_global_list(h->epoll_fd);
-  gpr_free(h);
-}
-
-static const grpc_pollset_vtable multipoll_with_epoll_pollset = {
-    multipoll_with_epoll_pollset_add_fd,
-    multipoll_with_epoll_pollset_maybe_work_and_unlock,
-    multipoll_with_epoll_pollset_finish_shutdown,
-    multipoll_with_epoll_pollset_destroy};
-
-static void epoll_become_multipoller(grpc_exec_ctx *exec_ctx,
-                                     grpc_pollset *pollset, grpc_fd **fds,
-                                     size_t nfds) {
-  size_t i;
-  pollset_hdr *h = gpr_malloc(sizeof(pollset_hdr));
-  struct epoll_event ev;
-  int err;
-
-  pollset->vtable = &multipoll_with_epoll_pollset;
-  pollset->data.ptr = h;
-  h->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
-  if (h->epoll_fd < 0) {
-    /* TODO(klempner): Fall back to poll here, especially on ENOSYS */
-    gpr_log(GPR_ERROR, "epoll_create1 failed: %s", strerror(errno));
-    abort();
-  }
-  add_epoll_fd_to_global_list(h->epoll_fd);
-
-  ev.events = (uint32_t)(EPOLLIN | EPOLLET);
-  ev.data.ptr = NULL;
-  err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD,
-                  GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), &ev);
-  if (err < 0) {
-    gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s",
-            GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd),
-            strerror(errno));
-  }
-
-  for (i = 0; i < nfds; i++) {
-    multipoll_with_epoll_pollset_add_fd(exec_ctx, pollset, fds[i], 0);
-  }
-}
-
-grpc_platform_become_multipoller_type grpc_platform_become_multipoller =
-    epoll_become_multipoller;
-
-#else /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
-
-void grpc_remove_fd_from_all_epoll_sets(int fd) {}
-
-#endif /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
diff --git a/src/core/lib/iomgr/pollset_multipoller_with_poll_posix.c b/src/core/lib/iomgr/pollset_multipoller_with_poll_posix.c
deleted file mode 100644
index 9b33f6dbb2..0000000000
--- a/src/core/lib/iomgr/pollset_multipoller_with_poll_posix.c
+++ /dev/null
@@ -1,234 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_SOCKET
-
-#include "src/core/lib/iomgr/pollset_posix.h"
-
-#include <errno.h>
-#include <poll.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
-#include "src/core/lib/support/block_annotate.h"
-
-typedef struct {
-  /* all polled fds */
-  size_t fd_count;
-  size_t fd_capacity;
-  grpc_fd **fds;
-  /* fds that have been removed from the pollset explicitly */
-  size_t del_count;
-  size_t del_capacity;
-  grpc_fd **dels;
-} pollset_hdr;
-
-static void multipoll_with_poll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
-                                               grpc_pollset *pollset,
-                                               grpc_fd *fd,
-                                               int and_unlock_pollset) {
-  size_t i;
-  pollset_hdr *h = pollset->data.ptr;
-  /* TODO(ctiller): this is O(num_fds^2); maybe switch to a hash set here */
-  for (i = 0; i < h->fd_count; i++) {
-    if (h->fds[i] == fd) goto exit;
-  }
-  if (h->fd_count == h->fd_capacity) {
-    h->fd_capacity = GPR_MAX(h->fd_capacity + 8, h->fd_count * 3 / 2);
-    h->fds = gpr_realloc(h->fds, sizeof(grpc_fd *) * h->fd_capacity);
-  }
-  h->fds[h->fd_count++] = fd;
-  GRPC_FD_REF(fd, "multipoller");
-exit:
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
-static void multipoll_with_poll_pollset_maybe_work_and_unlock(
-    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
-    gpr_timespec deadline, gpr_timespec now) {
-#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
-#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
-
-  int timeout;
-  int r;
-  size_t i, j, fd_count;
-  nfds_t pfd_count;
-  pollset_hdr *h;
-  /* TODO(ctiller): inline some elements to avoid an allocation */
-  grpc_fd_watcher *watchers;
-  struct pollfd *pfds;
-
-  h = pollset->data.ptr;
-  timeout = grpc_poll_deadline_to_millis_timeout(deadline, now);
-  /* TODO(ctiller): perform just one malloc here if we exceed the inline case */
-  pfds = gpr_malloc(sizeof(*pfds) * (h->fd_count + 2));
-  watchers = gpr_malloc(sizeof(*watchers) * (h->fd_count + 2));
-  fd_count = 0;
-  pfd_count = 2;
-  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
-  pfds[0].events = POLLIN;
-  pfds[0].revents = 0;
-  pfds[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfds[1].events = POLLIN;
-  pfds[1].revents = 0;
-  for (i = 0; i < h->fd_count; i++) {
-    int remove = grpc_fd_is_orphaned(h->fds[i]);
-    for (j = 0; !remove && j < h->del_count; j++) {
-      if (h->fds[i] == h->dels[j]) remove = 1;
-    }
-    if (remove) {
-      GRPC_FD_UNREF(h->fds[i], "multipoller");
-    } else {
-      h->fds[fd_count++] = h->fds[i];
-      watchers[pfd_count].fd = h->fds[i];
-      GRPC_FD_REF(watchers[pfd_count].fd, "multipoller_start");
-      pfds[pfd_count].fd = h->fds[i]->fd;
-      pfds[pfd_count].revents = 0;
-      pfd_count++;
-    }
-  }
-  for (j = 0; j < h->del_count; j++) {
-    GRPC_FD_UNREF(h->dels[j], "multipoller_del");
-  }
-  h->del_count = 0;
-  h->fd_count = fd_count;
-  gpr_mu_unlock(&pollset->mu);
-
-  for (i = 2; i < pfd_count; i++) {
-    grpc_fd *fd = watchers[i].fd;
-    pfds[i].events = (short)grpc_fd_begin_poll(fd, pollset, worker, POLLIN,
-                                               POLLOUT, &watchers[i]);
-    GRPC_FD_UNREF(fd, "multipoller_start");
-  }
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  r = grpc_poll_function(pfds, pfd_count, timeout);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-
-  if (r < 0) {
-    if (errno != EINTR) {
-      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
-    }
-    for (i = 2; i < pfd_count; i++) {
-      grpc_fd_end_poll(exec_ctx, &watchers[i], 0, 0);
-    }
-  } else if (r == 0) {
-    for (i = 2; i < pfd_count; i++) {
-      grpc_fd_end_poll(exec_ctx, &watchers[i], 0, 0);
-    }
-  } else {
-    if (pfds[0].revents & POLLIN_CHECK) {
-      grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
-    }
-    if (pfds[1].revents & POLLIN_CHECK) {
-      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
-    }
-    for (i = 2; i < pfd_count; i++) {
-      if (watchers[i].fd == NULL) {
-        grpc_fd_end_poll(exec_ctx, &watchers[i], 0, 0);
-        continue;
-      }
-      grpc_fd_end_poll(exec_ctx, &watchers[i], pfds[i].revents & POLLIN_CHECK,
-                       pfds[i].revents & POLLOUT_CHECK);
-    }
-  }
-
-  gpr_free(pfds);
-  gpr_free(watchers);
-}
-
-static void multipoll_with_poll_pollset_finish_shutdown(grpc_pollset *pollset) {
-  size_t i;
-  pollset_hdr *h = pollset->data.ptr;
-  for (i = 0; i < h->fd_count; i++) {
-    GRPC_FD_UNREF(h->fds[i], "multipoller");
-  }
-  for (i = 0; i < h->del_count; i++) {
-    GRPC_FD_UNREF(h->dels[i], "multipoller_del");
-  }
-  h->fd_count = 0;
-  h->del_count = 0;
-}
-
-static void multipoll_with_poll_pollset_destroy(grpc_pollset *pollset) {
-  pollset_hdr *h = pollset->data.ptr;
-  multipoll_with_poll_pollset_finish_shutdown(pollset);
-  gpr_free(h->fds);
-  gpr_free(h->dels);
-  gpr_free(h);
-}
-
-static const grpc_pollset_vtable multipoll_with_poll_pollset = {
-    multipoll_with_poll_pollset_add_fd,
-    multipoll_with_poll_pollset_maybe_work_and_unlock,
-    multipoll_with_poll_pollset_finish_shutdown,
-    multipoll_with_poll_pollset_destroy};
-
-void grpc_poll_become_multipoller(grpc_exec_ctx *exec_ctx,
-                                  grpc_pollset *pollset, grpc_fd **fds,
-                                  size_t nfds) {
-  size_t i;
-  pollset_hdr *h = gpr_malloc(sizeof(pollset_hdr));
-  pollset->vtable = &multipoll_with_poll_pollset;
-  pollset->data.ptr = h;
-  h->fd_count = nfds;
-  h->fd_capacity = nfds;
-  h->fds = gpr_malloc(nfds * sizeof(grpc_fd *));
-  h->del_count = 0;
-  h->del_capacity = 0;
-  h->dels = NULL;
-  for (i = 0; i < nfds; i++) {
-    h->fds[i] = fds[i];
-    GRPC_FD_REF(fds[i], "multipoller");
-  }
-}
-
-#endif /* GPR_POSIX_SOCKET */
-
-#ifdef GPR_POSIX_MULTIPOLL_WITH_POLL
-grpc_platform_become_multipoller_type grpc_platform_become_multipoller =
-    grpc_poll_become_multipoller;
-#endif
diff --git a/src/core/lib/iomgr/pollset_posix.c b/src/core/lib/iomgr/pollset_posix.c
deleted file mode 100644
index 259c7bc194..0000000000
--- a/src/core/lib/iomgr/pollset_posix.c
+++ /dev/null
@@ -1,633 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_SOCKET
-
-#include "src/core/lib/iomgr/pollset_posix.h"
-
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/thd.h>
-#include <grpc/support/tls.h>
-#include <grpc/support/useful.h>
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/socket_utils_posix.h"
-#include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
-
-GPR_TLS_DECL(g_current_thread_poller);
-GPR_TLS_DECL(g_current_thread_worker);
-
-/** Default poll() function - a pointer so that it can be overridden by some
- *  tests */
-grpc_poll_function_type grpc_poll_function = poll;
-
-/** The alarm system needs to be able to wakeup 'some poller' sometimes
- *  (specifically when a new alarm needs to be triggered earlier than the next
- *  alarm 'epoch').
- *  This wakeup_fd gives us something to alert on when such a case occurs. */
-grpc_wakeup_fd grpc_global_wakeup_fd;
-
-static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->prev->next = worker->next;
-  worker->next->prev = worker->prev;
-}
-
-int grpc_pollset_has_workers(grpc_pollset *p) {
-  return p->root_worker.next != &p->root_worker;
-}
-
-static grpc_pollset_worker *pop_front_worker(grpc_pollset *p) {
-  if (grpc_pollset_has_workers(p)) {
-    grpc_pollset_worker *w = p->root_worker.next;
-    remove_worker(p, w);
-    return w;
-  } else {
-    return NULL;
-  }
-}
-
-static void push_back_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->next = &p->root_worker;
-  worker->prev = worker->next->prev;
-  worker->prev->next = worker->next->prev = worker;
-}
-
-static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->prev = &p->root_worker;
-  worker->next = worker->prev->next;
-  worker->prev->next = worker->next->prev = worker;
-}
-
-size_t grpc_pollset_size(void) { return sizeof(grpc_pollset); }
-
-void grpc_pollset_kick_ext(grpc_pollset *p,
-                           grpc_pollset_worker *specific_worker,
-                           uint32_t flags) {
-  GPR_TIMER_BEGIN("grpc_pollset_kick_ext", 0);
-
-  /* pollset->mu already held */
-  if (specific_worker != NULL) {
-    if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) {
-      GPR_TIMER_BEGIN("grpc_pollset_kick_ext.broadcast", 0);
-      GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
-      for (specific_worker = p->root_worker.next;
-           specific_worker != &p->root_worker;
-           specific_worker = specific_worker->next) {
-        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
-      }
-      p->kicked_without_pollers = 1;
-      GPR_TIMER_END("grpc_pollset_kick_ext.broadcast", 0);
-    } else if (gpr_tls_get(&g_current_thread_worker) !=
-               (intptr_t)specific_worker) {
-      GPR_TIMER_MARK("different_thread_worker", 0);
-      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
-        specific_worker->reevaluate_polling_on_wakeup = 1;
-      }
-      specific_worker->kicked_specifically = 1;
-      grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
-    } else if ((flags & GRPC_POLLSET_CAN_KICK_SELF) != 0) {
-      GPR_TIMER_MARK("kick_yoself", 0);
-      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
-        specific_worker->reevaluate_polling_on_wakeup = 1;
-      }
-      specific_worker->kicked_specifically = 1;
-      grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
-    }
-  } else if (gpr_tls_get(&g_current_thread_poller) != (intptr_t)p) {
-    GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
-    GPR_TIMER_MARK("kick_anonymous", 0);
-    specific_worker = pop_front_worker(p);
-    if (specific_worker != NULL) {
-      if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) {
-        GPR_TIMER_MARK("kick_anonymous_not_self", 0);
-        push_back_worker(p, specific_worker);
-        specific_worker = pop_front_worker(p);
-        if ((flags & GRPC_POLLSET_CAN_KICK_SELF) == 0 &&
-            gpr_tls_get(&g_current_thread_worker) ==
-                (intptr_t)specific_worker) {
-          push_back_worker(p, specific_worker);
-          specific_worker = NULL;
-        }
-      }
-      if (specific_worker != NULL) {
-        GPR_TIMER_MARK("finally_kick", 0);
-        push_back_worker(p, specific_worker);
-        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd);
-      }
-    } else {
-      GPR_TIMER_MARK("kicked_no_pollers", 0);
-      p->kicked_without_pollers = 1;
-    }
-  }
-
-  GPR_TIMER_END("grpc_pollset_kick_ext", 0);
-}
-
-void grpc_pollset_kick(grpc_pollset *p, grpc_pollset_worker *specific_worker) {
-  grpc_pollset_kick_ext(p, specific_worker, 0);
-}
-
-/* global state management */
-
-void grpc_pollset_global_init(void) {
-  gpr_tls_init(&g_current_thread_poller);
-  gpr_tls_init(&g_current_thread_worker);
-  grpc_wakeup_fd_global_init();
-  grpc_wakeup_fd_init(&grpc_global_wakeup_fd);
-}
-
-void grpc_pollset_global_shutdown(void) {
-  grpc_wakeup_fd_destroy(&grpc_global_wakeup_fd);
-  gpr_tls_destroy(&g_current_thread_poller);
-  gpr_tls_destroy(&g_current_thread_worker);
-  grpc_wakeup_fd_global_destroy();
-}
-
-void grpc_kick_poller(void) { grpc_wakeup_fd_wakeup(&grpc_global_wakeup_fd); }
-
-/* main interface */
-
-static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null);
-
-void grpc_pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
-  gpr_mu_init(&pollset->mu);
-  *mu = &pollset->mu;
-  pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker;
-  pollset->in_flight_cbs = 0;
-  pollset->shutting_down = 0;
-  pollset->called_shutdown = 0;
-  pollset->kicked_without_pollers = 0;
-  pollset->idle_jobs.head = pollset->idle_jobs.tail = NULL;
-  pollset->local_wakeup_cache = NULL;
-  pollset->kicked_without_pollers = 0;
-  become_basic_pollset(pollset, NULL);
-}
-
-void grpc_pollset_destroy(grpc_pollset *pollset) {
-  GPR_ASSERT(pollset->in_flight_cbs == 0);
-  GPR_ASSERT(!grpc_pollset_has_workers(pollset));
-  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
-  pollset->vtable->destroy(pollset);
-  while (pollset->local_wakeup_cache) {
-    grpc_cached_wakeup_fd *next = pollset->local_wakeup_cache->next;
-    grpc_wakeup_fd_destroy(&pollset->local_wakeup_cache->fd);
-    gpr_free(pollset->local_wakeup_cache);
-    pollset->local_wakeup_cache = next;
-  }
-}
-
-void grpc_pollset_reset(grpc_pollset *pollset) {
-  GPR_ASSERT(pollset->shutting_down);
-  GPR_ASSERT(pollset->in_flight_cbs == 0);
-  GPR_ASSERT(!grpc_pollset_has_workers(pollset));
-  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
-  pollset->vtable->destroy(pollset);
-  pollset->shutting_down = 0;
-  pollset->called_shutdown = 0;
-  pollset->kicked_without_pollers = 0;
-  become_basic_pollset(pollset, NULL);
-}
-
-void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                         grpc_fd *fd) {
-  gpr_mu_lock(&pollset->mu);
-  pollset->vtable->add_fd(exec_ctx, pollset, fd, 1);
-/* the following (enabled only in debug) will reacquire and then release
-   our lock - meaning that if the unlocking flag passed to add_fd above is
-   not respected, the code will deadlock (in a way that we have a chance of
-   debugging) */
-#ifndef NDEBUG
-  gpr_mu_lock(&pollset->mu);
-  gpr_mu_unlock(&pollset->mu);
-#endif
-}
-
-static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
-  GPR_ASSERT(grpc_closure_list_empty(pollset->idle_jobs));
-  pollset->vtable->finish_shutdown(pollset);
-  grpc_exec_ctx_enqueue(exec_ctx, pollset->shutdown_done, true, NULL);
-}
-
-void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                       grpc_pollset_worker **worker_hdl, gpr_timespec now,
-                       gpr_timespec deadline) {
-  grpc_pollset_worker worker;
-  *worker_hdl = &worker;
-
-  /* pollset->mu already held */
-  int added_worker = 0;
-  int locked = 1;
-  int queued_work = 0;
-  int keep_polling = 0;
-  GPR_TIMER_BEGIN("grpc_pollset_work", 0);
-  /* this must happen before we (potentially) drop pollset->mu */
-  worker.next = worker.prev = NULL;
-  worker.reevaluate_polling_on_wakeup = 0;
-  if (pollset->local_wakeup_cache != NULL) {
-    worker.wakeup_fd = pollset->local_wakeup_cache;
-    pollset->local_wakeup_cache = worker.wakeup_fd->next;
-  } else {
-    worker.wakeup_fd = gpr_malloc(sizeof(*worker.wakeup_fd));
-    grpc_wakeup_fd_init(&worker.wakeup_fd->fd);
-  }
-  worker.kicked_specifically = 0;
-  /* If there's work waiting for the pollset to be idle, and the
-     pollset is idle, then do that work */
-  if (!grpc_pollset_has_workers(pollset) &&
-      !grpc_closure_list_empty(pollset->idle_jobs)) {
-    GPR_TIMER_MARK("grpc_pollset_work.idle_jobs", 0);
-    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-    goto done;
-  }
-  /* If we're shutting down then we don't execute any extended work */
-  if (pollset->shutting_down) {
-    GPR_TIMER_MARK("grpc_pollset_work.shutting_down", 0);
-    goto done;
-  }
-  /* Give do_promote priority so we don't starve it out */
-  if (pollset->in_flight_cbs) {
-    GPR_TIMER_MARK("grpc_pollset_work.in_flight_cbs", 0);
-    gpr_mu_unlock(&pollset->mu);
-    locked = 0;
-    goto done;
-  }
-  /* Start polling, and keep doing so while we're being asked to
-     re-evaluate our pollers (this allows poll() based pollers to
-     ensure they don't miss wakeups) */
-  keep_polling = 1;
-  while (keep_polling) {
-    keep_polling = 0;
-    if (!pollset->kicked_without_pollers) {
-      if (!added_worker) {
-        push_front_worker(pollset, &worker);
-        added_worker = 1;
-        gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
-      }
-      gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset);
-      GPR_TIMER_BEGIN("maybe_work_and_unlock", 0);
-      pollset->vtable->maybe_work_and_unlock(exec_ctx, pollset, &worker,
-                                             deadline, now);
-      GPR_TIMER_END("maybe_work_and_unlock", 0);
-      locked = 0;
-      gpr_tls_set(&g_current_thread_poller, 0);
-    } else {
-      GPR_TIMER_MARK("grpc_pollset_work.kicked_without_pollers", 0);
-      pollset->kicked_without_pollers = 0;
-    }
-  /* Finished execution - start cleaning up.
-     Note that we may arrive here from outside the enclosing while() loop.
-     In that case we won't loop though as we haven't added worker to the
-     worker list, which means nobody could ask us to re-evaluate polling). */
-  done:
-    if (!locked) {
-      queued_work |= grpc_exec_ctx_flush(exec_ctx);
-      gpr_mu_lock(&pollset->mu);
-      locked = 1;
-    }
-    /* If we're forced to re-evaluate polling (via grpc_pollset_kick with
-       GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force
-       a loop */
-    if (worker.reevaluate_polling_on_wakeup) {
-      worker.reevaluate_polling_on_wakeup = 0;
-      pollset->kicked_without_pollers = 0;
-      if (queued_work || worker.kicked_specifically) {
-        /* If there's queued work on the list, then set the deadline to be
-           immediate so we get back out of the polling loop quickly */
-        deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
-      }
-      keep_polling = 1;
-    }
-  }
-  if (added_worker) {
-    remove_worker(pollset, &worker);
-    gpr_tls_set(&g_current_thread_worker, 0);
-  }
-  /* release wakeup fd to the local pool */
-  worker.wakeup_fd->next = pollset->local_wakeup_cache;
-  pollset->local_wakeup_cache = worker.wakeup_fd;
-  /* check shutdown conditions */
-  if (pollset->shutting_down) {
-    if (grpc_pollset_has_workers(pollset)) {
-      grpc_pollset_kick(pollset, NULL);
-    } else if (!pollset->called_shutdown && pollset->in_flight_cbs == 0) {
-      pollset->called_shutdown = 1;
-      gpr_mu_unlock(&pollset->mu);
-      finish_shutdown(exec_ctx, pollset);
-      grpc_exec_ctx_flush(exec_ctx);
-      /* Continuing to access pollset here is safe -- it is the caller's
-       * responsibility to not destroy when it has outstanding calls to
-       * grpc_pollset_work.
-       * TODO(dklempner): Can we refactor the shutdown logic to avoid this? */
-      gpr_mu_lock(&pollset->mu);
-    } else if (!grpc_closure_list_empty(pollset->idle_jobs)) {
-      grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-      gpr_mu_unlock(&pollset->mu);
-      grpc_exec_ctx_flush(exec_ctx);
-      gpr_mu_lock(&pollset->mu);
-    }
-  }
-  *worker_hdl = NULL;
-  GPR_TIMER_END("grpc_pollset_work", 0);
-}
-
-void grpc_pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                           grpc_closure *closure) {
-  GPR_ASSERT(!pollset->shutting_down);
-  pollset->shutting_down = 1;
-  pollset->shutdown_done = closure;
-  grpc_pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
-  if (!grpc_pollset_has_workers(pollset)) {
-    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-  }
-  if (!pollset->called_shutdown && pollset->in_flight_cbs == 0 &&
-      !grpc_pollset_has_workers(pollset)) {
-    pollset->called_shutdown = 1;
-    finish_shutdown(exec_ctx, pollset);
-  }
-}
-
-int grpc_poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                         gpr_timespec now) {
-  gpr_timespec timeout;
-  static const int64_t max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
-                                                   max_spin_polling_us,
-                                                   GPR_TIMESPAN))) <= 0) {
-    return 0;
-  }
-  timeout = gpr_time_sub(deadline, now);
-  return gpr_time_to_millis(gpr_time_add(
-      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
-}
-
-/*
- * basic_pollset - a vtable that provides polling for zero or one file
- *                 descriptor via poll()
- */
-
-typedef struct grpc_unary_promote_args {
-  const grpc_pollset_vtable *original_vtable;
-  grpc_pollset *pollset;
-  grpc_fd *fd;
-  grpc_closure promotion_closure;
-} grpc_unary_promote_args;
-
-static void basic_do_promote(grpc_exec_ctx *exec_ctx, void *args,
-                             bool success) {
-  grpc_unary_promote_args *up_args = args;
-  const grpc_pollset_vtable *original_vtable = up_args->original_vtable;
-  grpc_pollset *pollset = up_args->pollset;
-  grpc_fd *fd = up_args->fd;
-
-  /*
-   * This is quite tricky. There are a number of cases to keep in mind here:
-   * 1. fd may have been orphaned
-   * 2. The pollset may no longer be a unary poller (and we can't let case #1
-   * leak to other pollset types!)
-   * 3. pollset's fd (which may have changed) may have been orphaned
-   * 4. The pollset may be shutting down.
-   */
-
-  gpr_mu_lock(&pollset->mu);
-  /* First we need to ensure that nobody is polling concurrently */
-  GPR_ASSERT(!grpc_pollset_has_workers(pollset));
-
-  gpr_free(up_args);
-  /* At this point the pollset may no longer be a unary poller. In that case
-   * we should just call the right add function and be done. */
-  /* TODO(klempner): If we're not careful this could cause infinite recursion.
-   * That's not a problem for now because empty_pollset has a trivial poller
-   * and we don't have any mechanism to unbecome multipoller. */
-  pollset->in_flight_cbs--;
-  if (pollset->shutting_down) {
-    /* We don't care about this pollset anymore. */
-    if (pollset->in_flight_cbs == 0 && !pollset->called_shutdown) {
-      pollset->called_shutdown = 1;
-      finish_shutdown(exec_ctx, pollset);
-    }
-  } else if (grpc_fd_is_orphaned(fd)) {
-    /* Don't try to add it to anything, we'll drop our ref on it below */
-  } else if (pollset->vtable != original_vtable) {
-    pollset->vtable->add_fd(exec_ctx, pollset, fd, 0);
-  } else if (fd != pollset->data.ptr) {
-    grpc_fd *fds[2];
-    fds[0] = pollset->data.ptr;
-    fds[1] = fd;
-
-    if (fds[0] && !grpc_fd_is_orphaned(fds[0])) {
-      grpc_platform_become_multipoller(exec_ctx, pollset, fds,
-                                       GPR_ARRAY_SIZE(fds));
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-    } else {
-      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
-       * unary poller */
-      /* Note that it is possible that fds[1] is also orphaned at this point.
-       * That's okay, we'll correct it at the next add or poll. */
-      if (fds[0]) GRPC_FD_UNREF(fds[0], "basicpoll");
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    }
-  }
-
-  gpr_mu_unlock(&pollset->mu);
-
-  /* Matching ref in basic_pollset_add_fd */
-  GRPC_FD_UNREF(fd, "basicpoll_add");
-}
-
-static void basic_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                 grpc_fd *fd, int and_unlock_pollset) {
-  grpc_unary_promote_args *up_args;
-  GPR_ASSERT(fd);
-  if (fd == pollset->data.ptr) goto exit;
-
-  if (!grpc_pollset_has_workers(pollset)) {
-    /* Fast path -- no in flight cbs */
-    /* TODO(klempner): Comment this out and fix any test failures or establish
-     * they are due to timing issues */
-    grpc_fd *fds[2];
-    fds[0] = pollset->data.ptr;
-    fds[1] = fd;
-
-    if (fds[0] == NULL) {
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    } else if (!grpc_fd_is_orphaned(fds[0])) {
-      grpc_platform_become_multipoller(exec_ctx, pollset, fds,
-                                       GPR_ARRAY_SIZE(fds));
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-    } else {
-      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
-       * unary poller */
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    }
-    goto exit;
-  }
-
-  /* Now we need to promote. This needs to happen when we're not polling. Since
-   * this may be called from poll, the wait needs to happen asynchronously. */
-  GRPC_FD_REF(fd, "basicpoll_add");
-  pollset->in_flight_cbs++;
-  up_args = gpr_malloc(sizeof(*up_args));
-  up_args->fd = fd;
-  up_args->original_vtable = pollset->vtable;
-  up_args->pollset = pollset;
-  up_args->promotion_closure.cb = basic_do_promote;
-  up_args->promotion_closure.cb_arg = up_args;
-
-  grpc_closure_list_add(&pollset->idle_jobs, &up_args->promotion_closure, 1);
-  grpc_pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
-
-exit:
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
-static void basic_pollset_maybe_work_and_unlock(grpc_exec_ctx *exec_ctx,
-                                                grpc_pollset *pollset,
-                                                grpc_pollset_worker *worker,
-                                                gpr_timespec deadline,
-                                                gpr_timespec now) {
-#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
-#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
-
-  struct pollfd pfd[3];
-  grpc_fd *fd;
-  grpc_fd_watcher fd_watcher;
-  int timeout;
-  int r;
-  nfds_t nfds;
-
-  fd = pollset->data.ptr;
-  if (fd && grpc_fd_is_orphaned(fd)) {
-    GRPC_FD_UNREF(fd, "basicpoll");
-    fd = pollset->data.ptr = NULL;
-  }
-  timeout = grpc_poll_deadline_to_millis_timeout(deadline, now);
-  pfd[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
-  pfd[0].events = POLLIN;
-  pfd[0].revents = 0;
-  pfd[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfd[1].events = POLLIN;
-  pfd[1].revents = 0;
-  nfds = 2;
-  if (fd) {
-    pfd[2].fd = fd->fd;
-    pfd[2].revents = 0;
-    GRPC_FD_REF(fd, "basicpoll_begin");
-    gpr_mu_unlock(&pollset->mu);
-    pfd[2].events = (short)grpc_fd_begin_poll(fd, pollset, worker, POLLIN,
-                                              POLLOUT, &fd_watcher);
-    if (pfd[2].events != 0) {
-      nfds++;
-    }
-  } else {
-    gpr_mu_unlock(&pollset->mu);
-  }
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  /* poll fd count (argument 2) is shortened by one if we have no events
-     to poll on - such that it only includes the kicker */
-  GPR_TIMER_BEGIN("poll", 0);
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  r = grpc_poll_function(pfd, nfds, timeout);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-  GPR_TIMER_END("poll", 0);
-
-  if (r < 0) {
-    if (errno != EINTR) {
-      gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno));
-    }
-    if (fd) {
-      grpc_fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
-    }
-  } else if (r == 0) {
-    if (fd) {
-      grpc_fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
-    }
-  } else {
-    if (pfd[0].revents & POLLIN_CHECK) {
-      grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd);
-    }
-    if (pfd[1].revents & POLLIN_CHECK) {
-      grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd);
-    }
-    if (nfds > 2) {
-      grpc_fd_end_poll(exec_ctx, &fd_watcher, pfd[2].revents & POLLIN_CHECK,
-                       pfd[2].revents & POLLOUT_CHECK);
-    } else if (fd) {
-      grpc_fd_end_poll(exec_ctx, &fd_watcher, 0, 0);
-    }
-  }
-
-  if (fd) {
-    GRPC_FD_UNREF(fd, "basicpoll_begin");
-  }
-}
-
-static void basic_pollset_destroy(grpc_pollset *pollset) {
-  if (pollset->data.ptr != NULL) {
-    GRPC_FD_UNREF(pollset->data.ptr, "basicpoll");
-    pollset->data.ptr = NULL;
-  }
-}
-
-static const grpc_pollset_vtable basic_pollset = {
-    basic_pollset_add_fd, basic_pollset_maybe_work_and_unlock,
-    basic_pollset_destroy, basic_pollset_destroy};
-
-static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
-  pollset->vtable = &basic_pollset;
-  pollset->data.ptr = fd_or_null;
-  if (fd_or_null != NULL) {
-    GRPC_FD_REF(fd_or_null, "basicpoll");
-  }
-}
-
-#endif /* GPR_POSIX_POLLSET */
diff --git a/src/core/lib/iomgr/pollset_posix.h b/src/core/lib/iomgr/pollset_posix.h
deleted file mode 100644
index 7d8e9fc279..0000000000
--- a/src/core/lib/iomgr/pollset_posix.h
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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_POLLSET_POSIX_H
-#define GRPC_CORE_LIB_IOMGR_POLLSET_POSIX_H
-
-#include <poll.h>
-
-#include <grpc/support/sync.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/wakeup_fd_posix.h"
-
-typedef struct grpc_pollset_vtable grpc_pollset_vtable;
-
-/* forward declare only in this file to avoid leaking impl details via
-   pollset.h; real users of grpc_fd should always include 'fd_posix.h' and not
-   use the struct tag */
-struct grpc_fd;
-
-typedef struct grpc_cached_wakeup_fd {
-  grpc_wakeup_fd fd;
-  struct grpc_cached_wakeup_fd *next;
-} grpc_cached_wakeup_fd;
-
-struct grpc_pollset_worker {
-  grpc_cached_wakeup_fd *wakeup_fd;
-  int reevaluate_polling_on_wakeup;
-  int kicked_specifically;
-  struct grpc_pollset_worker *next;
-  struct grpc_pollset_worker *prev;
-};
-
-struct grpc_pollset {
-  /* pollsets under posix can mutate representation as fds are added and
-     removed.
-     For example, we may choose a poll() based implementation on linux for
-     few fds, and an epoll() based implementation for many fds */
-  const grpc_pollset_vtable *vtable;
-  gpr_mu mu;
-  grpc_pollset_worker root_worker;
-  int in_flight_cbs;
-  int shutting_down;
-  int called_shutdown;
-  int kicked_without_pollers;
-  grpc_closure *shutdown_done;
-  grpc_closure_list idle_jobs;
-  union {
-    int fd;
-    void *ptr;
-  } data;
-  /* Local cache of eventfds for workers */
-  grpc_cached_wakeup_fd *local_wakeup_cache;
-};
-
-struct grpc_pollset_vtable {
-  void (*add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                 struct grpc_fd *fd, int and_unlock_pollset);
-  void (*maybe_work_and_unlock)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                grpc_pollset_worker *worker,
-                                gpr_timespec deadline, gpr_timespec now);
-  void (*finish_shutdown)(grpc_pollset *pollset);
-  void (*destroy)(grpc_pollset *pollset);
-};
-
-/* Add an fd to a pollset */
-void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                         struct grpc_fd *fd);
-
-/* Returns the fd to listen on for kicks */
-int grpc_kick_read_fd(grpc_pollset *p);
-/* Call after polling has been kicked to leave the kicked state */
-void grpc_kick_drain(grpc_pollset *p);
-
-/* Convert a timespec to milliseconds:
-   - very small or negative poll times are clamped to zero to do a
-     non-blocking poll (which becomes spin polling)
-   - other small values are rounded up to one millisecond
-   - longer than a millisecond polls are rounded up to the next nearest
-     millisecond to avoid spinning
-   - infinite timeouts are converted to -1 */
-int grpc_poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                         gpr_timespec now);
-
-/* Allow kick to wakeup the currently polling worker */
-#define GRPC_POLLSET_CAN_KICK_SELF 1
-/* Force the wakee to repoll when awoken */
-#define GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP 2
-/* As per grpc_pollset_kick, with an extended set of flags (defined above)
-   -- mostly for fd_posix's use. */
-void grpc_pollset_kick_ext(grpc_pollset *p,
-                           grpc_pollset_worker *specific_worker,
-                           uint32_t flags);
-
-/* turn a pollset into a multipoller: platform specific */
-typedef void (*grpc_platform_become_multipoller_type)(grpc_exec_ctx *exec_ctx,
-                                                      grpc_pollset *pollset,
-                                                      struct grpc_fd **fds,
-                                                      size_t fd_count);
-extern grpc_platform_become_multipoller_type grpc_platform_become_multipoller;
-
-void grpc_poll_become_multipoller(grpc_exec_ctx *exec_ctx,
-                                  grpc_pollset *pollset, struct grpc_fd **fds,
-                                  size_t fd_count);
-
-/* Return 1 if the pollset has active threads in grpc_pollset_work (pollset must
- * be locked) */
-int grpc_pollset_has_workers(grpc_pollset *pollset);
-
-void grpc_remove_fd_from_all_epoll_sets(int fd);
-
-/* override to allow tests to hook poll() usage */
-/* NOTE: Any changes to grpc_poll_function must take place when the gRPC
-   is certainly not doing any polling anywhere.
-   Otherwise, there might be a race between changing the variable and actually
-   doing a polling operation */
-typedef int (*grpc_poll_function_type)(struct pollfd *, nfds_t, int);
-extern grpc_poll_function_type grpc_poll_function;
-extern grpc_wakeup_fd grpc_global_wakeup_fd;
-
-#endif /* GRPC_CORE_LIB_IOMGR_POLLSET_POSIX_H */
diff --git a/src/core/lib/iomgr/pollset_set.h b/src/core/lib/iomgr/pollset_set.h
index fb29d692d7..34bb728c41 100644
--- a/src/core/lib/iomgr/pollset_set.h
+++ b/src/core/lib/iomgr/pollset_set.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/pollset_set_posix.c b/src/core/lib/iomgr/pollset_set_posix.c
deleted file mode 100644
index d6142f9b6b..0000000000
--- a/src/core/lib/iomgr/pollset_set_posix.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- *
- * Copyright 2015-2016, 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 <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_SOCKET
-
-#include <stdlib.h>
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/pollset_posix.h"
-#include "src/core/lib/iomgr/pollset_set_posix.h"
-
-struct grpc_pollset_set {
-  gpr_mu mu;
-
-  size_t pollset_count;
-  size_t pollset_capacity;
-  grpc_pollset **pollsets;
-
-  size_t pollset_set_count;
-  size_t pollset_set_capacity;
-  struct grpc_pollset_set **pollset_sets;
-
-  size_t fd_count;
-  size_t fd_capacity;
-  grpc_fd **fds;
-};
-
-grpc_pollset_set *grpc_pollset_set_create(void) {
-  grpc_pollset_set *pollset_set = gpr_malloc(sizeof(*pollset_set));
-  memset(pollset_set, 0, sizeof(*pollset_set));
-  gpr_mu_init(&pollset_set->mu);
-  return pollset_set;
-}
-
-void grpc_pollset_set_destroy(grpc_pollset_set *pollset_set) {
-  size_t i;
-  gpr_mu_destroy(&pollset_set->mu);
-  for (i = 0; i < pollset_set->fd_count; i++) {
-    GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
-  }
-  gpr_free(pollset_set->pollsets);
-  gpr_free(pollset_set->pollset_sets);
-  gpr_free(pollset_set->fds);
-  gpr_free(pollset_set);
-}
-
-void grpc_pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
-                                  grpc_pollset_set *pollset_set,
-                                  grpc_pollset *pollset) {
-  size_t i, j;
-  gpr_mu_lock(&pollset_set->mu);
-  if (pollset_set->pollset_count == pollset_set->pollset_capacity) {
-    pollset_set->pollset_capacity =
-        GPR_MAX(8, 2 * pollset_set->pollset_capacity);
-    pollset_set->pollsets =
-        gpr_realloc(pollset_set->pollsets, pollset_set->pollset_capacity *
-                                               sizeof(*pollset_set->pollsets));
-  }
-  pollset_set->pollsets[pollset_set->pollset_count++] = pollset;
-  for (i = 0, j = 0; i < pollset_set->fd_count; i++) {
-    if (grpc_fd_is_orphaned(pollset_set->fds[i])) {
-      GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
-    } else {
-      grpc_pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]);
-      pollset_set->fds[j++] = pollset_set->fds[i];
-    }
-  }
-  pollset_set->fd_count = j;
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-void grpc_pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
-                                  grpc_pollset_set *pollset_set,
-                                  grpc_pollset *pollset) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  for (i = 0; i < pollset_set->pollset_count; i++) {
-    if (pollset_set->pollsets[i] == pollset) {
-      pollset_set->pollset_count--;
-      GPR_SWAP(grpc_pollset *, pollset_set->pollsets[i],
-               pollset_set->pollsets[pollset_set->pollset_count]);
-      break;
-    }
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-void grpc_pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
-                                      grpc_pollset_set *bag,
-                                      grpc_pollset_set *item) {
-  size_t i, j;
-  gpr_mu_lock(&bag->mu);
-  if (bag->pollset_set_count == bag->pollset_set_capacity) {
-    bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity);
-    bag->pollset_sets =
-        gpr_realloc(bag->pollset_sets,
-                    bag->pollset_set_capacity * sizeof(*bag->pollset_sets));
-  }
-  bag->pollset_sets[bag->pollset_set_count++] = item;
-  for (i = 0, j = 0; i < bag->fd_count; i++) {
-    if (grpc_fd_is_orphaned(bag->fds[i])) {
-      GRPC_FD_UNREF(bag->fds[i], "pollset_set");
-    } else {
-      grpc_pollset_set_add_fd(exec_ctx, item, bag->fds[i]);
-      bag->fds[j++] = bag->fds[i];
-    }
-  }
-  bag->fd_count = j;
-  gpr_mu_unlock(&bag->mu);
-}
-
-void grpc_pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
-                                      grpc_pollset_set *bag,
-                                      grpc_pollset_set *item) {
-  size_t i;
-  gpr_mu_lock(&bag->mu);
-  for (i = 0; i < bag->pollset_set_count; i++) {
-    if (bag->pollset_sets[i] == item) {
-      bag->pollset_set_count--;
-      GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i],
-               bag->pollset_sets[bag->pollset_set_count]);
-      break;
-    }
-  }
-  gpr_mu_unlock(&bag->mu);
-}
-
-void grpc_pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
-                             grpc_pollset_set *pollset_set, grpc_fd *fd) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  if (pollset_set->fd_count == pollset_set->fd_capacity) {
-    pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity);
-    pollset_set->fds = gpr_realloc(
-        pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds));
-  }
-  GRPC_FD_REF(fd, "pollset_set");
-  pollset_set->fds[pollset_set->fd_count++] = fd;
-  for (i = 0; i < pollset_set->pollset_count; i++) {
-    grpc_pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd);
-  }
-  for (i = 0; i < pollset_set->pollset_set_count; i++) {
-    grpc_pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
-                             grpc_pollset_set *pollset_set, grpc_fd *fd) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  for (i = 0; i < pollset_set->fd_count; i++) {
-    if (pollset_set->fds[i] == fd) {
-      pollset_set->fd_count--;
-      GPR_SWAP(grpc_fd *, pollset_set->fds[i],
-               pollset_set->fds[pollset_set->fd_count]);
-      GRPC_FD_UNREF(fd, "pollset_set");
-      break;
-    }
-  }
-  for (i = 0; i < pollset_set->pollset_set_count; i++) {
-    grpc_pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-#endif /* GPR_POSIX_SOCKET */
diff --git a/src/core/lib/iomgr/pollset_set_windows.c b/src/core/lib/iomgr/pollset_set_windows.c
index 0b14e446ae..89f60b92fb 100644
--- a/src/core/lib/iomgr/pollset_set_windows.c
+++ b/src/core/lib/iomgr/pollset_set_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -37,7 +37,7 @@
 
 #include "src/core/lib/iomgr/pollset_set_windows.h"
 
-grpc_pollset_set* grpc_pollset_set_create(pollset_set) { return NULL; }
+grpc_pollset_set* grpc_pollset_set_create(void) { return NULL; }
 
 void grpc_pollset_set_destroy(grpc_pollset_set* pollset_set) {}
 
diff --git a/src/core/lib/iomgr/pollset_set_windows.h b/src/core/lib/iomgr/pollset_set_windows.h
index 7c2cea23de..0356749b15 100644
--- a/src/core/lib/iomgr/pollset_set_windows.h
+++ b/src/core/lib/iomgr/pollset_set_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/pollset_windows.c b/src/core/lib/iomgr/pollset_windows.c
index 6b339127a8..bff5c586f8 100644
--- a/src/core/lib/iomgr/pollset_windows.c
+++ b/src/core/lib/iomgr/pollset_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,7 +47,7 @@ gpr_mu grpc_polling_mu;
 static grpc_pollset_worker *g_active_poller;
 static grpc_pollset_worker g_global_root_worker;
 
-void grpc_pollset_global_init() {
+void grpc_pollset_global_init(void) {
   gpr_mu_init(&grpc_polling_mu);
   g_active_poller = NULL;
   g_global_root_worker.links[GRPC_POLLSET_WORKER_LINK_GLOBAL].next =
@@ -55,7 +55,7 @@ void grpc_pollset_global_init() {
           &g_global_root_worker;
 }
 
-void grpc_pollset_global_shutdown() { gpr_mu_destroy(&grpc_polling_mu); }
+void grpc_pollset_global_shutdown(void) { gpr_mu_destroy(&grpc_polling_mu); }
 
 static void remove_worker(grpc_pollset_worker *worker,
                           grpc_pollset_worker_link_type type) {
diff --git a/src/core/lib/iomgr/pollset_windows.h b/src/core/lib/iomgr/pollset_windows.h
index fa9553ffea..2642013afc 100644
--- a/src/core/lib/iomgr/pollset_windows.h
+++ b/src/core/lib/iomgr/pollset_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -72,4 +72,7 @@ struct grpc_pollset {
   grpc_closure *on_shutdown;
 };
 
+void grpc_pollset_global_init(void);
+void grpc_pollset_global_shutdown(void);
+
 #endif /* GRPC_CORE_LIB_IOMGR_POLLSET_WINDOWS_H */
diff --git a/src/core/lib/iomgr/resolve_address.h b/src/core/lib/iomgr/resolve_address.h
index f748288685..ecc06340a3 100644
--- a/src/core/lib/iomgr/resolve_address.h
+++ b/src/core/lib/iomgr/resolve_address.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/resolve_address_posix.c b/src/core/lib/iomgr/resolve_address_posix.c
index ebecb39c16..b9d3bbdb89 100644
--- a/src/core/lib/iomgr/resolve_address_posix.c
+++ b/src/core/lib/iomgr/resolve_address_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/resolve_address_windows.c b/src/core/lib/iomgr/resolve_address_windows.c
index bde1f1b7f7..82763d11f4 100644
--- a/src/core/lib/iomgr/resolve_address_windows.c
+++ b/src/core/lib/iomgr/resolve_address_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/sockaddr.h b/src/core/lib/iomgr/sockaddr.h
index 66a930ee6a..891a2f094f 100644
--- a/src/core/lib/iomgr/sockaddr.h
+++ b/src/core/lib/iomgr/sockaddr.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/sockaddr_posix.h b/src/core/lib/iomgr/sockaddr_posix.h
index 79a7467c5d..b150de42f7 100644
--- a/src/core/lib/iomgr/sockaddr_posix.h
+++ b/src/core/lib/iomgr/sockaddr_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/sockaddr_utils.h b/src/core/lib/iomgr/sockaddr_utils.h
index 20a3e3bec3..9f81992e6b 100644
--- a/src/core/lib/iomgr/sockaddr_utils.h
+++ b/src/core/lib/iomgr/sockaddr_utils.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/sockaddr_win32.h b/src/core/lib/iomgr/sockaddr_win32.h
index 2dd7111240..02aeae7619 100644
--- a/src/core/lib/iomgr/sockaddr_win32.h
+++ b/src/core/lib/iomgr/sockaddr_win32.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index 9dbc2784e4..fa83ceef30 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -89,6 +89,28 @@ int grpc_set_socket_no_sigpipe_if_possible(int fd) {
 #endif
 }
 
+int grpc_set_socket_ip_pktinfo_if_possible(int fd) {
+#ifdef GPR_HAVE_IP_PKTINFO
+  int get_local_ip = 1;
+  return 0 == setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &get_local_ip,
+                         sizeof(get_local_ip));
+#else
+  (void)fd;
+  return 1;
+#endif
+}
+
+int grpc_set_socket_ipv6_recvpktinfo_if_possible(int fd) {
+#ifdef GPR_HAVE_IPV6_RECVPKTINFO
+  int get_local_ip = 1;
+  return 0 == setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &get_local_ip,
+                         sizeof(get_local_ip));
+#else
+  (void)fd;
+  return 1;
+#endif
+}
+
 /* set a socket to close on exec */
 int grpc_set_socket_cloexec(int fd, int close_on_exec) {
   int oldflags = fcntl(fd, F_GETFD, 0);
diff --git a/src/core/lib/iomgr/socket_utils_linux.c b/src/core/lib/iomgr/socket_utils_linux.c
index e7dfe892ca..144e3110c8 100644
--- a/src/core/lib/iomgr/socket_utils_linux.c
+++ b/src/core/lib/iomgr/socket_utils_linux.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/socket_utils_posix.c b/src/core/lib/iomgr/socket_utils_posix.c
index b2fa00c5c1..57ae64c103 100644
--- a/src/core/lib/iomgr/socket_utils_posix.c
+++ b/src/core/lib/iomgr/socket_utils_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 063f298d72..a8f6e5e658 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -68,6 +68,16 @@ int grpc_ipv6_loopback_available(void);
    If SO_NO_SIGPIPE is not available, returns 1. */
 int grpc_set_socket_no_sigpipe_if_possible(int fd);
 
+/* Tries to set IP_PKTINFO if available on this platform.
+   Returns 1 on success, 0 on failure.
+   If IP_PKTINFO is not available, returns 1. */
+int grpc_set_socket_ip_pktinfo_if_possible(int fd);
+
+/* Tries to set IPV6_RECVPKTINFO if available on this platform.
+   Returns 1 on success, 0 on failure.
+   If IPV6_RECVPKTINFO is not available, returns 1. */
+int grpc_set_socket_ipv6_recvpktinfo_if_possible(int fd);
+
 /* An enum to keep track of IPv4/IPv6 socket modes.
 
    Currently, this information is only used when a socket is first created, but
diff --git a/src/core/lib/iomgr/socket_windows.c b/src/core/lib/iomgr/socket_windows.c
index 1023a6d4f8..ebd77e0372 100644
--- a/src/core/lib/iomgr/socket_windows.c
+++ b/src/core/lib/iomgr/socket_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/socket_windows.h b/src/core/lib/iomgr/socket_windows.h
index 74447896c9..73c4384987 100644
--- a/src/core/lib/iomgr/socket_windows.h
+++ b/src/core/lib/iomgr/socket_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index 6bbe26445a..a07e0b9f0c 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index b8ef643298..6430cb629f 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,9 +47,8 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_posix.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
-#include "src/core/lib/iomgr/pollset_set_posix.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
@@ -140,7 +139,8 @@ static void on_writable(grpc_exec_ctx *exec_ctx, void *acp, bool success) {
   if (success) {
     do {
       so_error_size = sizeof(so_error);
-      err = getsockopt(fd->fd, SOL_SOCKET, SO_ERROR, &so_error, &so_error_size);
+      err = getsockopt(grpc_fd_wrapped_fd(fd), SOL_SOCKET, SO_ERROR, &so_error,
+                       &so_error_size);
     } while (err < 0 && errno == EINTR);
     if (err < 0) {
       gpr_log(GPR_ERROR, "failed to connect to '%s': getsockopt(ERROR): %s",
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index 86b8d58975..7d78beb15a 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -103,7 +103,8 @@ static void on_connect(grpc_exec_ctx *exec_ctx, void *acp, bool from_iocp) {
     GPR_ASSERT(transfered_bytes == 0);
     if (!wsa_success) {
       char *utf8_message = gpr_format_message(WSAGetLastError());
-      gpr_log(GPR_ERROR, "on_connect error: %s", utf8_message);
+      gpr_log(GPR_ERROR, "on_connect error connecting to '%s': %s",
+              ac->addr_name, utf8_message);
       gpr_free(utf8_message);
     } else {
       *ep = grpc_tcp_create(ac->socket, ac->addr_name);
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 1898d96901..7210aef5d5 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -52,8 +52,7 @@
 #include <grpc/support/time.h>
 
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
-#include "src/core/lib/iomgr/pollset_set_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/string.h"
 
@@ -454,7 +453,7 @@ grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd, size_t slice_size,
   grpc_tcp *tcp = (grpc_tcp *)gpr_malloc(sizeof(grpc_tcp));
   tcp->base.vtable = &vtable;
   tcp->peer_string = gpr_strdup(peer_string);
-  tcp->fd = em_fd->fd;
+  tcp->fd = grpc_fd_wrapped_fd(em_fd);
   tcp->read_cb = NULL;
   tcp->write_cb = NULL;
   tcp->release_fd_cb = NULL;
diff --git a/src/core/lib/iomgr/tcp_posix.h b/src/core/lib/iomgr/tcp_posix.h
index 09c4436f1f..99125836d6 100644
--- a/src/core/lib/iomgr/tcp_posix.h
+++ b/src/core/lib/iomgr/tcp_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45,7 +45,7 @@
 */
 
 #include "src/core/lib/iomgr/endpoint.h"
-#include "src/core/lib/iomgr/fd_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 
 #define GRPC_TCP_DEFAULT_READ_SLICE_SIZE 8192
 
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 81edb61997..99b9f29729 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index e9c7f4ef5c..aaeb384f6e 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,7 +59,6 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
-#include "src/core/lib/iomgr/pollset_posix.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index 3db92aa41a..6940dec7b0 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index c1ce725f2c..7ee689a7e4 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/tcp_windows.h b/src/core/lib/iomgr/tcp_windows.h
index 7a9ebd85eb..a2f58eddd5 100644
--- a/src/core/lib/iomgr/tcp_windows.h
+++ b/src/core/lib/iomgr/tcp_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/time_averaged_stats.c b/src/core/lib/iomgr/time_averaged_stats.c
index f24d68087e..da9cae6f28 100644
--- a/src/core/lib/iomgr/time_averaged_stats.c
+++ b/src/core/lib/iomgr/time_averaged_stats.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/time_averaged_stats.h b/src/core/lib/iomgr/time_averaged_stats.h
index 4a662e17ec..284b31f94a 100644
--- a/src/core/lib/iomgr/time_averaged_stats.h
+++ b/src/core/lib/iomgr/time_averaged_stats.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/timer.c b/src/core/lib/iomgr/timer.c
index 4748f9b270..713f15b69e 100644
--- a/src/core/lib/iomgr/timer.c
+++ b/src/core/lib/iomgr/timer.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/timer.h b/src/core/lib/iomgr/timer.h
index 54f301c5ed..a825d2a28b 100644
--- a/src/core/lib/iomgr/timer.h
+++ b/src/core/lib/iomgr/timer.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/timer_heap.c b/src/core/lib/iomgr/timer_heap.c
index d43b6ccf75..2ad9bb9cd2 100644
--- a/src/core/lib/iomgr/timer_heap.c
+++ b/src/core/lib/iomgr/timer_heap.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/timer_heap.h b/src/core/lib/iomgr/timer_heap.h
index d5112cf0de..576c20e09a 100644
--- a/src/core/lib/iomgr/timer_heap.h
+++ b/src/core/lib/iomgr/timer_heap.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index 06f5d3dc8b..24131179af 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -60,12 +60,10 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
-#include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
 
 #define INIT_PORT_CAP 2
@@ -208,8 +206,6 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
                           size_t addr_len) {
   struct sockaddr_storage sockname_temp;
   socklen_t sockname_len;
-  int get_local_ip;
-  int rc;
 
   if (fd < 0) {
     goto error;
@@ -220,14 +216,9 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
             strerror(errno));
   }
 
-  get_local_ip = 1;
-  rc = setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &get_local_ip,
-                  sizeof(get_local_ip));
-  if (rc == 0 && addr->sa_family == AF_INET6) {
-#if !defined(__APPLE__)
-    rc = setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &get_local_ip,
-                    sizeof(get_local_ip));
-#endif
+  if (grpc_set_socket_ip_pktinfo_if_possible(fd) &&
+      addr->sa_family == AF_INET6) {
+    grpc_set_socket_ipv6_recvpktinfo_if_possible(fd);
   }
 
   GPR_ASSERT(addr_len < ~(socklen_t)0);
diff --git a/src/core/lib/iomgr/udp_server.h b/src/core/lib/iomgr/udp_server.h
index 316845ad66..d8cf957a22 100644
--- a/src/core/lib/iomgr/udp_server.h
+++ b/src/core/lib/iomgr/udp_server.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,7 +35,7 @@
 #define GRPC_CORE_LIB_IOMGR_UDP_SERVER_H
 
 #include "src/core/lib/iomgr/endpoint.h"
-#include "src/core/lib/iomgr/fd_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 
 /* Forward decl of struct grpc_server */
 /* This is not typedef'ed to avoid a typedef-redefinition error */
diff --git a/src/core/lib/iomgr/unix_sockets_posix_noop.c b/src/core/lib/iomgr/unix_sockets_posix_noop.c
index 06f6ee05e7..43e006e15e 100644
--- a/src/core/lib/iomgr/unix_sockets_posix_noop.c
+++ b/src/core/lib/iomgr/unix_sockets_posix_noop.c
@@ -35,7 +35,12 @@
 
 #ifndef GPR_HAVE_UNIX_SOCKET
 
-void grpc_create_socketpair_if_unix(int sv[2]) {}
+void grpc_create_socketpair_if_unix(int sv[2]) {
+  // TODO: Either implement this for the non-Unix socket case or make
+  // sure that it is never called in any such case. Until then, leave an
+  // assertion to notify if this gets called inadvertently
+  GPR_ASSERT(0);
+}
 
 grpc_resolved_addresses *grpc_resolve_unix_domain_address(const char *name) {
   return NULL;
diff --git a/src/core/lib/iomgr/wakeup_fd_eventfd.c b/src/core/lib/iomgr/wakeup_fd_eventfd.c
index 41ded0ca4d..8a772add13 100644
--- a/src/core/lib/iomgr/wakeup_fd_eventfd.c
+++ b/src/core/lib/iomgr/wakeup_fd_eventfd.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/wakeup_fd_nospecial.c b/src/core/lib/iomgr/wakeup_fd_nospecial.c
index 39defa65c6..cb2f707dc5 100644
--- a/src/core/lib/iomgr/wakeup_fd_nospecial.c
+++ b/src/core/lib/iomgr/wakeup_fd_nospecial.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index 820919e4dd..e9b9a0119f 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.h b/src/core/lib/iomgr/wakeup_fd_pipe.h
index bbdb1fc448..8972efc270 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.h
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.c b/src/core/lib/iomgr/wakeup_fd_posix.c
index c4d174fb34..525369c356 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.c
+++ b/src/core/lib/iomgr/wakeup_fd_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.h b/src/core/lib/iomgr/wakeup_fd_posix.h
index 20988d5fd3..6b069c1837 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.h
+++ b/src/core/lib/iomgr/wakeup_fd_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
index 9c420c57de..3e2b223670 100644
--- a/src/core/lib/iomgr/workqueue.h
+++ b/src/core/lib/iomgr/workqueue.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/workqueue_posix.c b/src/core/lib/iomgr/workqueue_posix.c
index 76830ef12d..80e7a0b206 100644
--- a/src/core/lib/iomgr/workqueue_posix.c
+++ b/src/core/lib/iomgr/workqueue_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -43,8 +43,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/lib/iomgr/fd_posix.h"
-#include "src/core/lib/iomgr/pollset_posix.h"
+#include "src/core/lib/iomgr/ev_posix.h"
 
 static void on_readable(grpc_exec_ctx *exec_ctx, void *arg, bool success);
 
diff --git a/src/core/lib/iomgr/workqueue_posix.h b/src/core/lib/iomgr/workqueue_posix.h
index 956de8fb27..dcb47e7b59 100644
--- a/src/core/lib/iomgr/workqueue_posix.h
+++ b/src/core/lib/iomgr/workqueue_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/workqueue_windows.c b/src/core/lib/iomgr/workqueue_windows.c
index 6697f93498..c3c0446a57 100644
--- a/src/core/lib/iomgr/workqueue_windows.c
+++ b/src/core/lib/iomgr/workqueue_windows.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/workqueue_windows.h b/src/core/lib/iomgr/workqueue_windows.h
index 8e6980b6d9..e5d59130bb 100644
--- a/src/core/lib/iomgr/workqueue_windows.h
+++ b/src/core/lib/iomgr/workqueue_windows.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without