Merge remote-tracking branch 'upstream/master' into latency_in_final_info

39 files changed, 488 insertions, 192 deletions

diff --git a/src/core/ext/census/census_log.h b/src/core/ext/census/census_log.h
index 534ecc5705..1b185a53b9 100644
--- a/src/core/ext/census/census_log.h
+++ b/src/core/ext/census/census_log.h
@@ -84,7 +84,7 @@ const void *census_log_read_next(size_t *bytes_available);
 */
 size_t census_log_remaining_space(void);
 
-/* Returns the number of times gprc_stats_log_start_write() failed due to
+/* Returns the number of times grpc_stats_log_start_write() failed due to
    out-of-space. */
 int census_log_out_of_space_count(void);
 
diff --git a/src/core/ext/census/mlog.h b/src/core/ext/census/mlog.h
index a256426f91..18805ad994 100644
--- a/src/core/ext/census/mlog.h
+++ b/src/core/ext/census/mlog.h
@@ -88,7 +88,7 @@ const void* census_log_read_next(size_t* bytes_available);
 */
 size_t census_log_remaining_space(void);
 
-/* Returns the number of times gprc_stats_log_start_write() failed due to
+/* Returns the number of times grpc_stats_log_start_write() failed due to
    out-of-space. */
 int64_t census_log_out_of_space_count(void);
 
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index 41e177c495..44ac9a017e 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -186,6 +186,7 @@ static void wrapped_rr_closure(grpc_exec_ctx *exec_ctx, void *arg,
      * addresses failed to connect). There won't be any user_data/token
      * available */
     if (wc_arg->target != NULL) {
+      GPR_ASSERT(wc_arg->lb_token != NULL);
       initial_metadata_add_lb_token(wc_arg->initial_metadata,
                                     wc_arg->lb_token_mdelem_storage,
                                     GRPC_MDELEM_REF(wc_arg->lb_token));
@@ -605,10 +606,10 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
    * right grpclb status. */
   rr_connectivity_data *rr_conn_data = arg;
   glb_lb_policy *glb_policy = rr_conn_data->glb_policy;
+  gpr_mu_lock(&glb_policy->mu);
 
   if (rr_conn_data->state != GRPC_CHANNEL_SHUTDOWN &&
       !glb_policy->shutting_down) {
-    gpr_mu_lock(&glb_policy->mu);
     /* RR not shutting down. Mimic the RR's policy state */
     grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker,
                                 rr_conn_data->state, GRPC_ERROR_REF(error),
@@ -617,12 +618,12 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
                                           &rr_conn_data->state,
                                           &rr_conn_data->on_change);
-    gpr_mu_unlock(&glb_policy->mu);
   } else {
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                               "rr_connectivity_cb");
     gpr_free(rr_conn_data);
   }
+  gpr_mu_unlock(&glb_policy->mu);
 }
 
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
@@ -1081,6 +1082,7 @@ static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_op ops[2];
   memset(ops, 0, sizeof(ops));
   grpc_op *op = ops;
+  gpr_mu_lock(&glb_policy->mu);
   if (glb_policy->lb_response_payload != NULL) {
     gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
     /* Received data from the LB server. Look inside
@@ -1109,7 +1111,6 @@ static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
 
       /* update serverlist */
       if (serverlist->num_servers > 0) {
-        gpr_mu_lock(&glb_policy->mu);
         if (grpc_grpclb_serverlist_equals(glb_policy->serverlist, serverlist)) {
           if (grpc_lb_glb_trace) {
             gpr_log(GPR_INFO,
@@ -1125,7 +1126,6 @@ static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
 
           rr_handover_locked(exec_ctx, glb_policy, error);
         }
-        gpr_mu_unlock(&glb_policy->mu);
       } else {
         if (grpc_lb_glb_trace) {
           gpr_log(GPR_INFO,
@@ -1153,9 +1153,11 @@ static void lb_on_response_received(grpc_exec_ctx *exec_ctx, void *arg,
           &glb_policy->lb_on_response_received); /* loop */
       GPR_ASSERT(GRPC_CALL_OK == call_error);
     }
+    gpr_mu_unlock(&glb_policy->mu);
   } else { /* empty payload: call cancelled. */
            /* dispose of the "lb_on_response_received" weak ref taken in
             * query_for_backends_locked() and reused in every reception loop */
+    gpr_mu_unlock(&glb_policy->mu);
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                               "lb_on_response_received_empty_payload");
   }
@@ -1175,7 +1177,6 @@ static void lb_call_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
     query_for_backends_locked(exec_ctx, glb_policy);
   }
   gpr_mu_unlock(&glb_policy->mu);
-
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                             "grpclb_on_retry_timer");
 }
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 1ffa9165b2..fb8fbae0ab 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -2294,6 +2294,14 @@ static char *chttp2_get_peer(grpc_exec_ctx *exec_ctx, grpc_transport *t) {
   return gpr_strdup(((grpc_chttp2_transport *)t)->peer_string);
 }
 
+/*******************************************************************************
+ * MONITORING
+ */
+static grpc_endpoint *chttp2_get_endpoint(grpc_exec_ctx *exec_ctx,
+                                          grpc_transport *t) {
+  return ((grpc_chttp2_transport *)t)->ep;
+}
+
 static const grpc_transport_vtable vtable = {sizeof(grpc_chttp2_stream),
                                              "chttp2",
                                              init_stream,
@@ -2303,7 +2311,8 @@ static const grpc_transport_vtable vtable = {sizeof(grpc_chttp2_stream),
                                              perform_transport_op,
                                              destroy_stream,
                                              destroy_transport,
-                                             chttp2_get_peer};
+                                             chttp2_get_peer,
+                                             chttp2_get_endpoint};
 
 grpc_transport *grpc_create_chttp2_transport(
     grpc_exec_ctx *exec_ctx, const grpc_channel_args *channel_args,
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index 2ab9a8c19d..a4c110101e 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -42,6 +42,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/ext/transport/chttp2/transport/incoming_metadata.h"
+#include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/channel.h"
@@ -1095,6 +1096,11 @@ static char *get_peer(grpc_exec_ctx *exec_ctx, grpc_transport *gt) {
   return NULL;
 }
 
+static grpc_endpoint *get_endpoint(grpc_exec_ctx *exec_ctx,
+                                   grpc_transport *gt) {
+  return NULL;
+}
+
 static void perform_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                        grpc_transport_op *op) {}
 
@@ -1107,4 +1113,5 @@ const grpc_transport_vtable grpc_cronet_vtable = {sizeof(stream_obj),
                                                   perform_op,
                                                   destroy_stream,
                                                   destroy_transport,
-                                                  get_peer};
+                                                  get_peer,
+                                                  get_endpoint};
diff --git a/src/core/lib/channel/channel_args.c b/src/core/lib/channel/channel_args.c
index cfc072c0b5..401a2ad4fe 100644
--- a/src/core/lib/channel/channel_args.c
+++ b/src/core/lib/channel/channel_args.c
@@ -298,6 +298,12 @@ uint32_t grpc_channel_args_compression_algorithm_get_states(
   }
 }
 
+grpc_channel_args *grpc_channel_args_set_socket_mutator(
+    grpc_channel_args *a, grpc_socket_mutator *mutator) {
+  grpc_arg tmp = grpc_socket_mutator_to_arg(mutator);
+  return grpc_channel_args_copy_and_add(a, &tmp, 1);
+}
+
 int grpc_channel_args_compare(const grpc_channel_args *a,
                               const grpc_channel_args *b) {
   int c = GPR_ICMP(a->num_args, b->num_args);
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index 1e05303471..88fc0e37a3 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -36,6 +36,7 @@
 
 #include <grpc/compression.h>
 #include <grpc/grpc.h>
+#include "src/core/lib/iomgr/socket_mutator.h"
 
 // Channel args are intentionally immutable, to avoid the need for locking.
 
@@ -100,6 +101,13 @@ uint32_t grpc_channel_args_compression_algorithm_get_states(
 int grpc_channel_args_compare(const grpc_channel_args *a,
                               const grpc_channel_args *b);
 
+/** Returns a channel arg instance with socket mutator added. The socket mutator
+ * will perform its mutate_fd method on all file descriptors used by the
+ * channel.
+ * If \a a is non-MULL, its args are copied. */
+grpc_channel_args *grpc_channel_args_set_socket_mutator(
+    grpc_channel_args *a, grpc_socket_mutator *mutator);
+
 /** Returns the value of argument \a name from \a args, or NULL if not found. */
 const grpc_arg *grpc_channel_args_find(const grpc_channel_args *args,
                                        const char *name);
diff --git a/src/core/lib/iomgr/endpoint.c b/src/core/lib/iomgr/endpoint.c
index a4b6668276..2d300f4560 100644
--- a/src/core/lib/iomgr/endpoint.c
+++ b/src/core/lib/iomgr/endpoint.c
@@ -66,6 +66,8 @@ char* grpc_endpoint_get_peer(grpc_endpoint* ep) {
   return ep->vtable->get_peer(ep);
 }
 
+int grpc_endpoint_get_fd(grpc_endpoint* ep) { return ep->vtable->get_fd(ep); }
+
 grpc_workqueue* grpc_endpoint_get_workqueue(grpc_endpoint* ep) {
   return ep->vtable->get_workqueue(ep);
 }
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index bf211ca16a..1609b64f2b 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -61,6 +61,7 @@ struct grpc_endpoint_vtable {
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
   grpc_resource_user *(*get_resource_user)(grpc_endpoint *ep);
   char *(*get_peer)(grpc_endpoint *ep);
+  int (*get_fd)(grpc_endpoint *ep);
 };
 
 /* When data is available on the connection, calls the callback with slices.
@@ -73,6 +74,10 @@ void grpc_endpoint_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
 char *grpc_endpoint_get_peer(grpc_endpoint *ep);
 
+/* Get the file descriptor used by \a ep. Return -1 if \a ep is not using an fd.
+   */
+int grpc_endpoint_get_fd(grpc_endpoint *ep);
+
 /* Retrieve a reference to the workqueue associated with this endpoint */
 grpc_workqueue *grpc_endpoint_get_workqueue(grpc_endpoint *ep);
 
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index db51ec4939..91041a7c28 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -163,7 +163,7 @@ static void fd_global_shutdown(void);
 #define PI_ADD_REF(p, r) pi_add_ref((p))
 #define PI_UNREF(exec_ctx, p, r) pi_unref((exec_ctx), (p))
 
-#endif /* !defined(GPRC_PI_REF_COUNT_DEBUG) */
+#endif /* !defined(GRPC_PI_REF_COUNT_DEBUG) */
 
 /* This is also used as grpc_workqueue (by directly casing it) */
 typedef struct polling_island {
diff --git a/src/core/lib/iomgr/socket_mutator.c b/src/core/lib/iomgr/socket_mutator.c
new file mode 100644
index 0000000000..8b1efb6bab
--- /dev/null
+++ b/src/core/lib/iomgr/socket_mutator.c
@@ -0,0 +1,98 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/socket_mutator.h"
+
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/useful.h>
+
+void grpc_socket_mutator_init(grpc_socket_mutator *mutator,
+                              const grpc_socket_mutator_vtable *vtable) {
+  mutator->vtable = vtable;
+  gpr_ref_init(&mutator->refcount, 1);
+}
+
+grpc_socket_mutator *grpc_socket_mutator_ref(grpc_socket_mutator *mutator) {
+  gpr_ref(&mutator->refcount);
+  return mutator;
+}
+
+bool grpc_socket_mutator_mutate_fd(grpc_socket_mutator *mutator, int fd) {
+  return mutator->vtable->mutate_fd(fd, mutator);
+}
+
+int grpc_socket_mutator_compare(grpc_socket_mutator *a,
+                                grpc_socket_mutator *b) {
+  int c = GPR_ICMP(a, b);
+  if (c != 0) {
+    grpc_socket_mutator *sma = a;
+    grpc_socket_mutator *smb = b;
+    c = GPR_ICMP(sma->vtable, smb->vtable);
+    if (c == 0) {
+      c = sma->vtable->compare(sma, smb);
+    }
+  }
+  return c;
+}
+
+void grpc_socket_mutator_unref(grpc_socket_mutator *mutator) {
+  if (gpr_unref(&mutator->refcount)) {
+    mutator->vtable->destory(mutator);
+  }
+}
+
+static void *socket_mutator_arg_copy(void *p) {
+  return grpc_socket_mutator_ref(p);
+}
+
+static void socket_mutator_arg_destroy(void *p) {
+  grpc_socket_mutator_unref(p);
+}
+
+static int socket_mutator_cmp(void *a, void *b) {
+  return grpc_socket_mutator_compare((grpc_socket_mutator *)a,
+                                     (grpc_socket_mutator *)b);
+}
+
+static const grpc_arg_pointer_vtable socket_mutator_arg_vtable = {
+    socket_mutator_arg_copy, socket_mutator_arg_destroy, socket_mutator_cmp};
+
+grpc_arg grpc_socket_mutator_to_arg(grpc_socket_mutator *mutator) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_SOCKET_MUTATOR;
+  arg.value.pointer.vtable = &socket_mutator_arg_vtable;
+  arg.value.pointer.p = mutator;
+  return arg;
+}
diff --git a/src/core/lib/iomgr/socket_mutator.h b/src/core/lib/iomgr/socket_mutator.h
new file mode 100644
index 0000000000..2f5b6c248e
--- /dev/null
+++ b/src/core/lib/iomgr/socket_mutator.h
@@ -0,0 +1,80 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
+#define GRPC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
+
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** The virtual table of grpc_socket_mutator */
+typedef struct {
+  /** Mutates the socket opitons of \a fd */
+  bool (*mutate_fd)(int fd, grpc_socket_mutator *mutator);
+  /** Compare socket mutator \a a and \a b */
+  int (*compare)(grpc_socket_mutator *a, grpc_socket_mutator *b);
+  /** Destroys the socket mutator instance */
+  void (*destory)(grpc_socket_mutator *mutator);
+} grpc_socket_mutator_vtable;
+
+/** The Socket Mutator interface allows changes on socket options */
+struct grpc_socket_mutator {
+  const grpc_socket_mutator_vtable *vtable;
+  gpr_refcount refcount;
+};
+
+/** called by concrete implementations to initialize the base struct */
+void grpc_socket_mutator_init(grpc_socket_mutator *mutator,
+                              const grpc_socket_mutator_vtable *vtable);
+
+/** Wrap \a mutator as a grpc_arg */
+grpc_arg grpc_socket_mutator_to_arg(grpc_socket_mutator *mutator);
+
+/** Perform the file descriptor mutation operation of \a mutator on \a fd */
+bool grpc_socket_mutator_mutate_fd(grpc_socket_mutator *mutator, int fd);
+
+/** Compare if \a a and \a b are the same mutator or have same settings */
+int grpc_socket_mutator_compare(grpc_socket_mutator *a, grpc_socket_mutator *b);
+
+grpc_socket_mutator *grpc_socket_mutator_ref(grpc_socket_mutator *mutator);
+void grpc_socket_mutator_unref(grpc_socket_mutator *mutator);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H */
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index bc28bbe316..88e9ade253 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -209,6 +209,15 @@ grpc_error *grpc_set_socket_low_latency(int fd, int low_latency) {
   return GRPC_ERROR_NONE;
 }
 
+/* set a socket using a grpc_socket_mutator */
+grpc_error *grpc_set_socket_with_mutator(int fd, grpc_socket_mutator *mutator) {
+  GPR_ASSERT(mutator);
+  if (!grpc_socket_mutator_mutate_fd(mutator, fd)) {
+    return GRPC_ERROR_CREATE("grpc_socket_mutator failed.");
+  }
+  return GRPC_ERROR_NONE;
+}
+
 static gpr_once g_probe_ipv6_once = GPR_ONCE_INIT;
 static int g_ipv6_loopback_available;
 
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 175fb2b717..e84d3781a1 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -39,7 +39,9 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
+#include <grpc/impl/codegen/grpc_types.h>
 #include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/socket_mutator.h"
 
 /* a wrapper for accept or accept4 */
 int grpc_accept4(int sockfd, grpc_resolved_address *resolved_addr, int nonblock,
@@ -88,6 +90,9 @@ grpc_error *grpc_set_socket_sndbuf(int fd, int buffer_size_bytes);
 /* Tries to set the socket's receive buffer to given size. */
 grpc_error *grpc_set_socket_rcvbuf(int fd, int buffer_size_bytes);
 
+/* Tries to set the socket using a grpc_socket_mutator */
+grpc_error *grpc_set_socket_with_mutator(int fd, grpc_socket_mutator *mutator);
+
 /* 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/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index 18e6e60ebc..0485661316 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -34,6 +34,7 @@
 #ifndef GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H
 #define GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H
 
+#include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/pollset_set.h"
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index bc08c94ee0..13347735df 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -51,6 +51,7 @@
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_posix.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/iomgr/socket_mutator.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
 #include "src/core/lib/iomgr/timer.h"
@@ -73,7 +74,8 @@ typedef struct {
   grpc_channel_args *channel_args;
 } async_connect;
 
-static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd) {
+static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd,
+                                  const grpc_channel_args *channel_args) {
   grpc_error *err = GRPC_ERROR_NONE;
 
   GPR_ASSERT(fd >= 0);
@@ -88,6 +90,16 @@ static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd) {
   }
   err = grpc_set_socket_no_sigpipe_if_possible(fd);
   if (err != GRPC_ERROR_NONE) goto error;
+  if (channel_args) {
+    for (size_t i = 0; i < channel_args->num_args; i++) {
+      if (0 == strcmp(channel_args->args[i].key, GRPC_ARG_SOCKET_MUTATOR)) {
+        GPR_ASSERT(channel_args->args[i].type == GRPC_ARG_POINTER);
+        grpc_socket_mutator *mutator = channel_args->args[i].value.pointer.p;
+        err = grpc_set_socket_with_mutator(fd, mutator);
+        if (err != GRPC_ERROR_NONE) goto error;
+      }
+    }
+  }
   goto done;
 
 error:
@@ -287,7 +299,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
     GPR_ASSERT(grpc_sockaddr_is_v4mapped(addr, &addr4_copy));
     addr = &addr4_copy;
   }
-  if ((error = prepare_socket(addr, fd)) != GRPC_ERROR_NONE) {
+  if ((error = prepare_socket(addr, fd, channel_args)) != GRPC_ERROR_NONE) {
     grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
     return;
   }
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index c48f4e83cf..12a4797e6f 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -493,6 +493,11 @@ static char *tcp_get_peer(grpc_endpoint *ep) {
   return gpr_strdup(tcp->peer_string);
 }
 
+static int tcp_get_fd(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  return tcp->fd;
+}
+
 static grpc_workqueue *tcp_get_workqueue(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   return grpc_fd_get_workqueue(tcp->em_fd);
@@ -511,7 +516,8 @@ static const grpc_endpoint_vtable vtable = {tcp_read,
                                             tcp_shutdown,
                                             tcp_destroy,
                                             tcp_get_resource_user,
-                                            tcp_get_peer};
+                                            tcp_get_peer,
+                                            tcp_get_fd};
 
 grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd,
                                grpc_resource_quota *resource_quota,
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
index 8b58c04ff5..6e2ad1dbe9 100644
--- a/src/core/lib/iomgr/tcp_uv.c
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -38,14 +38,17 @@
 #include <limits.h>
 #include <string.h>
 
+#include <grpc/slice_buffer.h>
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/network_status_tracker.h"
+#include "src/core/lib/iomgr/resource_quota.h"
 #include "src/core/lib/iomgr/tcp_uv.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 
 int grpc_tcp_trace = 0;
@@ -62,15 +65,14 @@ typedef struct {
   grpc_closure *read_cb;
   grpc_closure *write_cb;
 
-  GRPC_SLICE read_slice;
-  GRPC_SLICE_buffer *read_slices;
-  GRPC_SLICE_buffer *write_slices;
+  grpc_slice read_slice;
+  grpc_slice_buffer *read_slices;
+  grpc_slice_buffer *write_slices;
   uv_buf_t *write_buffers;
 
-  grpc_resource_user resource_user;
+  grpc_resource_user *resource_user;
 
   bool shutting_down;
-  bool resource_user_shutting_down;
 
   char *peer_string;
   grpc_pollset *pollset;
@@ -78,23 +80,23 @@ typedef struct {
 
 static void uv_close_callback(uv_handle_t *handle) { gpr_free(handle); }
 
-static void tcp_free(grpc_tcp *tcp) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_resource_user_destroy(&exec_ctx, &tcp->resource_user);
+static void tcp_free(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
+  grpc_resource_user_unref(exec_ctx, tcp->resource_user);
   gpr_free(tcp);
-  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 /*#define GRPC_TCP_REFCOUNT_DEBUG*/
 #ifdef GRPC_TCP_REFCOUNT_DEBUG
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp), (reason), __FILE__, __LINE__)
-#define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
-static void tcp_unref(grpc_tcp *tcp, const char *reason, const char *file,
-                      int line) {
+#define TCP_UNREF(exec_ctx, tcp, reason) \
+  tcp_unref((exec_ctx), (tcp), (reason), __FILE__, __LINE__)
+#define TCP_REF(tcp, reason) \
+  tcp_ref((exec_ctx), (tcp), (reason), __FILE__, __LINE__)
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
+                      const char *reason, const char *file, int line) {
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "TCP unref %p : %s %d -> %d", tcp,
           reason, tcp->refcount.count, tcp->refcount.count - 1);
   if (gpr_unref(&tcp->refcount)) {
-    tcp_free(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
@@ -105,11 +107,11 @@ static void tcp_ref(grpc_tcp *tcp, const char *reason, const char *file,
   gpr_ref(&tcp->refcount);
 }
 #else
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp))
+#define TCP_UNREF(exec_ctx, tcp, reason) tcp_unref((exec_ctx), (tcp))
 #define TCP_REF(tcp, reason) tcp_ref((tcp))
-static void tcp_unref(grpc_tcp *tcp) {
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   if (gpr_unref(&tcp->refcount)) {
-    tcp_free(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
@@ -122,7 +124,7 @@ static void alloc_uv_buf(uv_handle_t *handle, size_t suggested_size,
   grpc_tcp *tcp = handle->data;
   (void)suggested_size;
   tcp->read_slice = grpc_resource_user_slice_malloc(
-      &exec_ctx, &tcp->resource_user, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
+      &exec_ctx, tcp->resource_user, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
   buf->base = (char *)GRPC_SLICE_START_PTR(tcp->read_slice);
   buf->len = GRPC_SLICE_LENGTH(tcp->read_slice);
   grpc_exec_ctx_finish(&exec_ctx);
@@ -130,7 +132,7 @@ static void alloc_uv_buf(uv_handle_t *handle, size_t suggested_size,
 
 static void read_callback(uv_stream_t *stream, ssize_t nread,
                           const uv_buf_t *buf) {
-  GRPC_SLICE sub;
+  grpc_slice sub;
   grpc_error *error;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_tcp *tcp = stream->data;
@@ -139,7 +141,7 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
     // Nothing happened. Wait for the next callback
     return;
   }
-  TCP_UNREF(tcp, "read");
+  TCP_UNREF(&exec_ctx, tcp, "read");
   tcp->read_cb = NULL;
   // TODO(murgatroid99): figure out what the return value here means
   uv_read_stop(stream);
@@ -147,8 +149,8 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
     error = GRPC_ERROR_CREATE("EOF");
   } else if (nread > 0) {
     // Successful read
-    sub = GRPC_SLICE_sub_no_ref(tcp->read_slice, 0, (size_t)nread);
-    GRPC_SLICE_buffer_add(tcp->read_slices, sub);
+    sub = grpc_slice_sub_no_ref(tcp->read_slice, 0, (size_t)nread);
+    grpc_slice_buffer_add(tcp->read_slices, sub);
     error = GRPC_ERROR_NONE;
     if (grpc_tcp_trace) {
       size_t i;
@@ -156,8 +158,8 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
       gpr_log(GPR_DEBUG, "read: error=%s", str);
       grpc_error_free_string(str);
       for (i = 0; i < tcp->read_slices->count; i++) {
-        char *dump = gpr_dump_slice(tcp->read_slices->slices[i],
-                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
+        char *dump = grpc_dump_slice(tcp->read_slices->slices[i],
+                                     GPR_DUMP_HEX | GPR_DUMP_ASCII);
         gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string,
                 dump);
         gpr_free(dump);
@@ -172,14 +174,14 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
 }
 
 static void uv_endpoint_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                             GRPC_SLICE_buffer *read_slices, grpc_closure *cb) {
+                             grpc_slice_buffer *read_slices, grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   int status;
   grpc_error *error = GRPC_ERROR_NONE;
   GPR_ASSERT(tcp->read_cb == NULL);
   tcp->read_cb = cb;
   tcp->read_slices = read_slices;
-  GRPC_SLICE_buffer_reset_and_unref(read_slices);
+  grpc_slice_buffer_reset_and_unref(read_slices);
   TCP_REF(tcp, "read");
   // TODO(murgatroid99): figure out what the return value here means
   status =
@@ -202,7 +204,7 @@ static void write_callback(uv_write_t *req, int status) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_closure *cb = tcp->write_cb;
   tcp->write_cb = NULL;
-  TCP_UNREF(tcp, "write");
+  TCP_UNREF(&exec_ctx, tcp, "write");
   if (status == 0) {
     error = GRPC_ERROR_NONE;
   } else {
@@ -213,28 +215,28 @@ static void write_callback(uv_write_t *req, int status) {
     gpr_log(GPR_DEBUG, "write complete on %p: error=%s", tcp, str);
   }
   gpr_free(tcp->write_buffers);
-  grpc_resource_user_free(&exec_ctx, &tcp->resource_user,
+  grpc_resource_user_free(&exec_ctx, tcp->resource_user,
                           sizeof(uv_buf_t) * tcp->write_slices->count);
   grpc_exec_ctx_sched(&exec_ctx, cb, error, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                              GRPC_SLICE_buffer *write_slices,
+                              grpc_slice_buffer *write_slices,
                               grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   uv_buf_t *buffers;
   unsigned int buffer_count;
   unsigned int i;
-  GRPC_SLICE *slice;
+  grpc_slice *slice;
   uv_write_t *write_req;
 
   if (grpc_tcp_trace) {
     size_t j;
 
     for (j = 0; j < write_slices->count; j++) {
-      char *data = gpr_dump_slice(write_slices->slices[j],
-                                  GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      char *data = grpc_dump_slice(write_slices->slices[j],
+                                   GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
       gpr_free(data);
     }
@@ -259,7 +261,7 @@ static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   tcp->write_cb = cb;
   buffer_count = (unsigned int)tcp->write_slices->count;
   buffers = gpr_malloc(sizeof(uv_buf_t) * buffer_count);
-  grpc_resource_user_alloc(exec_ctx, &tcp->resource_user,
+  grpc_resource_user_alloc(exec_ctx, tcp->resource_user,
                            sizeof(uv_buf_t) * buffer_count, NULL);
   for (i = 0; i < buffer_count; i++) {
     slice = &tcp->write_slices->slices[i];
@@ -295,22 +297,6 @@ static void uv_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
 static void shutdown_callback(uv_shutdown_t *req, int status) {}
 
-static void resource_user_shutdown_done(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
-  TCP_UNREF(arg, "resource_user");
-}
-
-static void uv_resource_user_maybe_shutdown(grpc_exec_ctx *exec_ctx,
-                                            grpc_tcp *tcp) {
-  if (!tcp->resource_user_shutting_down) {
-    tcp->resource_user_shutting_down = true;
-    TCP_REF(tcp, "resource_user");
-    grpc_resource_user_shutdown(
-        exec_ctx, &tcp->resource_user,
-        grpc_closure_create(resource_user_shutdown_done, tcp));
-  }
-}
-
 static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   if (!tcp->shutting_down) {
@@ -324,8 +310,7 @@ static void uv_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
   uv_close((uv_handle_t *)tcp->handle, uv_close_callback);
-  uv_resource_user_maybe_shutdown(exec_ctx, tcp);
-  TCP_UNREF(tcp, "destroy");
+  TCP_UNREF(exec_ctx, tcp, "destroy");
 }
 
 static char *uv_get_peer(grpc_endpoint *ep) {
@@ -335,15 +320,18 @@ static char *uv_get_peer(grpc_endpoint *ep) {
 
 static grpc_resource_user *uv_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  return &tcp->resource_user;
+  return tcp->resource_user;
 }
 
 static grpc_workqueue *uv_get_workqueue(grpc_endpoint *ep) { return NULL; }
 
+static int uv_get_fd(grpc_endpoint *ep) { return -1; }
+
 static grpc_endpoint_vtable vtable = {
     uv_endpoint_read,  uv_endpoint_write,     uv_get_workqueue,
     uv_add_to_pollset, uv_add_to_pollset_set, uv_endpoint_shutdown,
-    uv_destroy,        uv_get_resource_user,  uv_get_peer};
+    uv_destroy,        uv_get_resource_user,  uv_get_peer,
+    uv_get_fd};
 
 grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
                                grpc_resource_quota *resource_quota,
@@ -364,8 +352,7 @@ grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
   gpr_ref_init(&tcp->refcount, 1);
   tcp->peer_string = gpr_strdup(peer_string);
   tcp->shutting_down = false;
-  tcp->resource_user_shutting_down = false;
-  grpc_resource_user_init(&tcp->resource_user, resource_quota, peer_string);
+  tcp->resource_user = grpc_resource_user_create(resource_quota, peer_string);
   /* Tell network status tracking code about the new endpoint */
   grpc_network_status_register_endpoint(&tcp->base);
 
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 1fb7edc2b1..62afbcef51 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -402,6 +402,8 @@ static grpc_resource_user *win_get_resource_user(grpc_endpoint *ep) {
   return tcp->resource_user;
 }
 
+static int win_get_fd(grpc_endpoint *ep) { return -1; }
+
 static grpc_endpoint_vtable vtable = {win_read,
                                       win_write,
                                       win_get_workqueue,
@@ -410,7 +412,8 @@ static grpc_endpoint_vtable vtable = {win_read,
                                       win_shutdown,
                                       win_destroy,
                                       win_get_resource_user,
-                                      win_get_peer};
+                                      win_get_peer,
+                                      win_get_fd};
 
 grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket,
                                grpc_resource_quota *resource_quota,
diff --git a/src/core/lib/security/credentials/plugin/plugin_credentials.c b/src/core/lib/security/credentials/plugin/plugin_credentials.c
index 61c10862da..5d950098a0 100644
--- a/src/core/lib/security/credentials/plugin/plugin_credentials.c
+++ b/src/core/lib/security/credentials/plugin/plugin_credentials.c
@@ -104,6 +104,8 @@ static void plugin_md_request_metadata_ready(void *request,
         grpc_slice_unref(md_array[i].value);
       }
       gpr_free(md_array);
+    } else if (num_md == 0) {
+      r->cb(&exec_ctx, r->user_data, NULL, 0, GRPC_CREDENTIALS_OK, NULL);
     }
   }
   gpr_free(r);
diff --git a/src/core/lib/security/transport/handshake.c b/src/core/lib/security/transport/handshake.c
index 2eb5544f43..9623797610 100644
--- a/src/core/lib/security/transport/handshake.c
+++ b/src/core/lib/security/transport/handshake.c
@@ -125,7 +125,7 @@ static void security_handshake_done(grpc_exec_ctx *exec_ctx,
           h->auth_context);
   } else {
     const char *msg = grpc_error_string(error);
-    gpr_log(GPR_INFO, "Security handshake failed: %s", msg);
+    gpr_log(GPR_DEBUG, "Security handshake failed: %s", msg);
     grpc_error_free_string(msg);
 
     if (h->secure_endpoint != NULL) {
diff --git a/src/core/lib/security/transport/secure_endpoint.c b/src/core/lib/security/transport/secure_endpoint.c
index fba3314812..1b278410e8 100644
--- a/src/core/lib/security/transport/secure_endpoint.c
+++ b/src/core/lib/security/transport/secure_endpoint.c
@@ -31,7 +31,12 @@
  *
  */
 
-#include "src/core/lib/security/transport/secure_endpoint.h"
+/* With the addition of a libuv endpoint, sockaddr.h now includes uv.h when
+   using that endpoint. Because of various transitive includes in uv.h,
+   including windows.h on Windows, uv.h must be included before other system
+   headers. Therefore, sockaddr.h must always be included first */
+#include "src/core/lib/iomgr/sockaddr.h"
+
 #include <grpc/slice.h>
 #include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
@@ -39,6 +44,7 @@
 #include <grpc/support/sync.h>
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/security/transport/secure_endpoint.h"
 #include "src/core/lib/security/transport/tsi_error.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
@@ -366,6 +372,8 @@ static char *endpoint_get_peer(grpc_endpoint *secure_ep) {
   return grpc_endpoint_get_peer(ep->wrapped_ep);
 }
 
+static int endpoint_get_fd(grpc_endpoint *secure_ep) { return -1; }
+
 static grpc_workqueue *endpoint_get_workqueue(grpc_endpoint *secure_ep) {
   secure_endpoint *ep = (secure_endpoint *)secure_ep;
   return grpc_endpoint_get_workqueue(ep->wrapped_ep);
@@ -385,7 +393,8 @@ static const grpc_endpoint_vtable vtable = {endpoint_read,
                                             endpoint_shutdown,
                                             endpoint_destroy,
                                             endpoint_get_resource_user,
-                                            endpoint_get_peer};
+                                            endpoint_get_peer,
+                                            endpoint_get_fd};
 
 grpc_endpoint *grpc_secure_endpoint_create(
     struct tsi_frame_protector *protector, grpc_endpoint *transport,
diff --git a/src/core/lib/transport/transport.c b/src/core/lib/transport/transport.c
index 866cd9ea87..b448126da8 100644
--- a/src/core/lib/transport/transport.c
+++ b/src/core/lib/transport/transport.c
@@ -160,6 +160,11 @@ char *grpc_transport_get_peer(grpc_exec_ctx *exec_ctx,
   return transport->vtable->get_peer(exec_ctx, transport);
 }
 
+grpc_endpoint *grpc_transport_get_endpoint(grpc_exec_ctx *exec_ctx,
+                                           grpc_transport *transport) {
+  return transport->vtable->get_endpoint(exec_ctx, transport);
+}
+
 void grpc_transport_stream_op_finish_with_failure(grpc_exec_ctx *exec_ctx,
                                                   grpc_transport_stream_op *op,
                                                   grpc_error *error) {
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 8916b28b72..96c26749c8 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -37,6 +37,7 @@
 #include <stddef.h>
 
 #include "src/core/lib/channel/context.h"
+#include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
@@ -295,6 +296,10 @@ void grpc_transport_destroy(grpc_exec_ctx *exec_ctx, grpc_transport *transport);
 char *grpc_transport_get_peer(grpc_exec_ctx *exec_ctx,
                               grpc_transport *transport);
 
+/* Get the endpoint used by \a transport */
+grpc_endpoint *grpc_transport_get_endpoint(grpc_exec_ctx *exec_ctx,
+                                           grpc_transport *transport);
+
 /* Allocate a grpc_transport_op, and preconfigure the on_consumed closure to
    \a on_consumed and then delete the returned transport op */
 grpc_transport_op *grpc_make_transport_op(grpc_closure *on_consumed);
diff --git a/src/core/lib/transport/transport_impl.h b/src/core/lib/transport/transport_impl.h
index fc7140671b..8553148c35 100644
--- a/src/core/lib/transport/transport_impl.h
+++ b/src/core/lib/transport/transport_impl.h
@@ -74,6 +74,9 @@ typedef struct grpc_transport_vtable {
 
   /* implementation of grpc_transport_get_peer */
   char *(*get_peer)(grpc_exec_ctx *exec_ctx, grpc_transport *self);
+
+  /* implementation of grpc_transport_get_endpoint */
+  grpc_endpoint *(*get_endpoint)(grpc_exec_ctx *exec_ctx, grpc_transport *self);
 } grpc_transport_vtable;
 
 /* an instance of a grpc transport */
diff --git a/src/cpp/common/channel_arguments.cc b/src/cpp/common/channel_arguments.cc
index d86ba9dd4e..0067d6c5e1 100644
--- a/src/cpp/common/channel_arguments.cc
+++ b/src/cpp/common/channel_arguments.cc
@@ -39,7 +39,7 @@
 #include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/support/log.h>
 #include "src/core/lib/channel/channel_args.h"
-
+#include "src/core/lib/iomgr/socket_mutator.h"
 namespace grpc {
 
 ChannelArguments::ChannelArguments() {
@@ -88,6 +88,24 @@ void ChannelArguments::SetCompressionAlgorithm(
   SetInt(GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM, algorithm);
 }
 
+void ChannelArguments::SetSocketMutator(grpc_socket_mutator* mutator) {
+  if (!mutator) {
+    return;
+  }
+  grpc_arg mutator_arg = grpc_socket_mutator_to_arg(mutator);
+  bool replaced = false;
+  for (auto it = args_.begin(); it != args_.end(); ++it) {
+    if (it->type == mutator_arg.type &&
+        grpc::string(it->key) == grpc::string(mutator_arg.key)) {
+      it->value.pointer.vtable->destroy(it->value.pointer.p);
+      it->value.pointer = mutator_arg.value.pointer;
+    }
+  }
+  if (!replaced) {
+    args_.push_back(mutator_arg);
+  }
+}
+
 // Note: a second call to this will add in front the result of the first call.
 // An example is calling this on a copy of ChannelArguments which already has a
 // prefix. The user can build up a prefix string by calling this multiple times,
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCall.cs b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
index 5e61e9ec12..da45c4829d 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCall.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
@@ -388,35 +388,29 @@ namespace Grpc.Core.Internal
 
         private void Initialize(CompletionQueueSafeHandle cq)
         {
-            using (Profilers.ForCurrentThread().NewScope("AsyncCall.Initialize"))
-            { 
-                var call = CreateNativeCall(cq);
+            var call = CreateNativeCall(cq);
 
-                details.Channel.AddCallReference(this);
-                InitializeInternal(call);
-                RegisterCancellationCallback();
-            }
+            details.Channel.AddCallReference(this);
+            InitializeInternal(call);
+            RegisterCancellationCallback();
         }
 
         private INativeCall CreateNativeCall(CompletionQueueSafeHandle cq)
         {
-            using (Profilers.ForCurrentThread().NewScope("AsyncCall.CreateNativeCall"))
-            { 
-                if (injectedNativeCall != null)
-                {
-                    return injectedNativeCall;  // allows injecting a mock INativeCall in tests.
-                }
+            if (injectedNativeCall != null)
+            {
+                return injectedNativeCall;  // allows injecting a mock INativeCall in tests.
+            }
 
-                var parentCall = details.Options.PropagationToken != null ? details.Options.PropagationToken.ParentCall : CallSafeHandle.NullInstance;
+            var parentCall = details.Options.PropagationToken != null ? details.Options.PropagationToken.ParentCall : CallSafeHandle.NullInstance;
 
-                var credentials = details.Options.Credentials;
-                using (var nativeCredentials = credentials != null ? credentials.ToNativeCredentials() : null)
-                {
-                    var result = details.Channel.Handle.CreateCall(
-                                 parentCall, ContextPropagationToken.DefaultMask, cq,
-                                 details.Method, details.Host, Timespec.FromDateTime(details.Options.Deadline.Value), nativeCredentials);
-                    return result;
-                }
+            var credentials = details.Options.Credentials;
+            using (var nativeCredentials = credentials != null ? credentials.ToNativeCredentials() : null)
+            {
+                var result = details.Channel.Handle.CreateCall(
+                             parentCall, ContextPropagationToken.DefaultMask, cq,
+                             details.Method, details.Host, Timespec.FromDateTime(details.Options.Deadline.Value), nativeCredentials);
+                return result;
             }
         }
 
@@ -456,47 +450,44 @@ namespace Grpc.Core.Internal
             // NOTE: because this event is a result of batch containing GRPC_OP_RECV_STATUS_ON_CLIENT,
             // success will be always set to true.
 
-            using (Profilers.ForCurrentThread().NewScope("AsyncCall.HandleUnaryResponse"))
+            TaskCompletionSource<object> delayedStreamingWriteTcs = null;
+            TResponse msg = default(TResponse);
+            var deserializeException = TryDeserialize(receivedMessage, out msg);
+
+            lock (myLock)
             {
-                TaskCompletionSource<object> delayedStreamingWriteTcs = null;
-                TResponse msg = default(TResponse);
-                var deserializeException = TryDeserialize(receivedMessage, out msg);
+                finished = true;
 
-                lock (myLock)
+                if (deserializeException != null && receivedStatus.Status.StatusCode == StatusCode.OK)
                 {
-                    finished = true;
-
-                    if (deserializeException != null && receivedStatus.Status.StatusCode == StatusCode.OK)
-                    {
-                        receivedStatus = new ClientSideStatus(DeserializeResponseFailureStatus, receivedStatus.Trailers);
-                    }
-                    finishedStatus = receivedStatus;
-
-                    if (isStreamingWriteCompletionDelayed)
-                    {
-                        delayedStreamingWriteTcs = streamingWriteTcs;
-                        streamingWriteTcs = null;
-                    }
-
-                    ReleaseResourcesIfPossible();
+                    receivedStatus = new ClientSideStatus(DeserializeResponseFailureStatus, receivedStatus.Trailers);
                 }
+                finishedStatus = receivedStatus;
 
-                responseHeadersTcs.SetResult(responseHeaders);
-
-                if (delayedStreamingWriteTcs != null)
+                if (isStreamingWriteCompletionDelayed)
                 {
-                    delayedStreamingWriteTcs.SetException(GetRpcExceptionClientOnly());
+                    delayedStreamingWriteTcs = streamingWriteTcs;
+                    streamingWriteTcs = null;
                 }
 
-                var status = receivedStatus.Status;
-                if (status.StatusCode != StatusCode.OK)
-                {
-                    unaryResponseTcs.SetException(new RpcException(status));
-                    return;
-                }
+                ReleaseResourcesIfPossible();
+            }
+
+            responseHeadersTcs.SetResult(responseHeaders);
 
-                unaryResponseTcs.SetResult(msg);
+            if (delayedStreamingWriteTcs != null)
+            {
+                delayedStreamingWriteTcs.SetException(GetRpcExceptionClientOnly());
+            }
+
+            var status = receivedStatus.Status;
+            if (status.StatusCode != StatusCode.OK)
+            {
+                unaryResponseTcs.SetException(new RpcException(status));
+                return;
             }
+
+            unaryResponseTcs.SetResult(msg);
         }
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
index 9f9d260e7e..8668903f6e 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
@@ -181,19 +181,16 @@ namespace Grpc.Core.Internal
         /// </summary>
         protected bool ReleaseResourcesIfPossible()
         {
-            using (Profilers.ForCurrentThread().NewScope("AsyncCallBase.ReleaseResourcesIfPossible"))
+            if (!disposed && call != null)
             {
-                if (!disposed && call != null)
+                bool noMoreSendCompletions = streamingWriteTcs == null && (halfcloseRequested || cancelRequested || finished);
+                if (noMoreSendCompletions && readingDone && finished)
                 {
-                    bool noMoreSendCompletions = streamingWriteTcs == null && (halfcloseRequested || cancelRequested || finished);
-                    if (noMoreSendCompletions && readingDone && finished)
-                    {
-                        ReleaseResources();
-                        return true;
-                    }
+                    ReleaseResources();
+                    return true;
                 }
-                return false;
             }
+            return false;
         }
 
         protected abstract bool IsClient
@@ -229,28 +226,20 @@ namespace Grpc.Core.Internal
 
         protected byte[] UnsafeSerialize(TWrite msg)
         {
-            using (Profilers.ForCurrentThread().NewScope("AsyncCallBase.UnsafeSerialize"))
-            {
-                return serializer(msg);
-            }
+            return serializer(msg);
         }
 
         protected Exception TryDeserialize(byte[] payload, out TRead msg)
         {
-            using (Profilers.ForCurrentThread().NewScope("AsyncCallBase.TryDeserialize"))
+            try
             {
-                try
-                {
-                
-                    msg = deserializer(payload);
-                    return null;
-             
-                }
-                catch (Exception e)
-                {
-                    msg = default(TRead);
-                    return e;
-                }
+                msg = deserializer(payload);
+                return null;
+            }
+            catch (Exception e)
+            {
+                msg = default(TRead);
+                return e;
             }
         }
 
diff --git a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
index 82361f5797..f817a61bce 100644
--- a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
@@ -76,11 +76,8 @@ namespace Grpc.Core.Internal
 
         public void StartUnary(BatchContextSafeHandle ctx, byte[] payload, MetadataArraySafeHandle metadataArray, WriteFlags writeFlags)
         {
-            using (Profilers.ForCurrentThread().NewScope("CallSafeHandle.StartUnary"))
-            {
-                Native.grpcsharp_call_start_unary(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags)
-                    .CheckOk();
-            }
+            Native.grpcsharp_call_start_unary(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags)
+                .CheckOk();
         }
 
         public void StartClientStreaming(UnaryResponseClientHandler callback, MetadataArraySafeHandle metadataArray)
diff --git a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
index 62864dff0c..0fb6360a23 100644
--- a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
@@ -65,16 +65,13 @@ namespace Grpc.Core.Internal
 
         public CallSafeHandle CreateCall(CallSafeHandle parentCall, ContextPropagationFlags propagationMask, CompletionQueueSafeHandle cq, string method, string host, Timespec deadline, CallCredentialsSafeHandle credentials)
         {
-            using (Profilers.ForCurrentThread().NewScope("ChannelSafeHandle.CreateCall"))
+            var result = Native.grpcsharp_channel_create_call(this, parentCall, propagationMask, cq, method, host, deadline);
+            if (credentials != null)
             {
-                var result = Native.grpcsharp_channel_create_call(this, parentCall, propagationMask, cq, method, host, deadline);
-                if (credentials != null)
-                {
-                    result.SetCredentials(credentials);
-                }
-                result.Initialize(cq);
-                return result;
+                result.SetCredentials(credentials);
             }
+            result.Initialize(cq);
+            return result;
         }
 
         public ChannelState CheckConnectivityState(bool tryToConnect)
diff --git a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
index 46f5624223..6c9a31921e 100644
--- a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
@@ -70,10 +70,7 @@ namespace Grpc.Core.Internal
 
         public CompletionQueueEvent Pluck(IntPtr tag)
         {
-            using (Profilers.ForCurrentThread().NewScope("CompletionQueueSafeHandle.Pluck"))
-            {
-                return Native.grpcsharp_completion_queue_pluck(this, tag);
-            }
+            return Native.grpcsharp_completion_queue_pluck(this, tag);
         }
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
index a446c1f99f..25a6589f11 100644
--- a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
+++ b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
@@ -37,6 +37,7 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Grpc.Core.Logging;
+using Grpc.Core.Profiling;
 using Grpc.Core.Utils;
 
 namespace Grpc.Core.Internal
@@ -54,6 +55,8 @@ namespace Grpc.Core.Internal
         readonly int poolSize;
         readonly int completionQueueCount;
 
+        readonly List<BasicProfiler> threadProfilers = new List<BasicProfiler>();  // profilers assigned to threadpool threads
+
         bool stopRequested;
 
         IReadOnlyCollection<CompletionQueueSafeHandle> completionQueues;
@@ -82,7 +85,8 @@ namespace Grpc.Core.Internal
 
                 for (int i = 0; i < poolSize; i++)
                 {
-                    threads.Add(CreateAndStartThread(i));
+                    var optionalProfiler = i < threadProfilers.Count ? threadProfilers[i] : null;
+                    threads.Add(CreateAndStartThread(i, optionalProfiler));
                 }
             }
         }
@@ -111,6 +115,11 @@ namespace Grpc.Core.Internal
                 {
                     cq.Dispose();
                 }
+
+                for (int i = 0; i < threadProfilers.Count; i++)
+                {
+                    threadProfilers[i].Dump(string.Format("grpc_trace_thread_{0}.txt", i));
+                }
             });
         }
 
@@ -137,12 +146,12 @@ namespace Grpc.Core.Internal
             }
         }
 
-        private Thread CreateAndStartThread(int threadIndex)
+        private Thread CreateAndStartThread(int threadIndex, IProfiler optionalProfiler)
         {
             var cqIndex = threadIndex % completionQueues.Count;
             var cq = completionQueues.ElementAt(cqIndex);
 
-            var thread = new Thread(new ThreadStart(() => RunHandlerLoop(cq)));
+            var thread = new Thread(new ThreadStart(() => RunHandlerLoop(cq, optionalProfiler)));
             thread.IsBackground = true;
             thread.Name = string.Format("grpc {0} (cq {1})", threadIndex, cqIndex);
             thread.Start();
@@ -153,8 +162,13 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Body of the polling thread.
         /// </summary>
-        private void RunHandlerLoop(CompletionQueueSafeHandle cq)
+        private void RunHandlerLoop(CompletionQueueSafeHandle cq, IProfiler optionalProfiler)
         {
+            if (optionalProfiler != null)
+            {
+                Profilers.SetForCurrentThread(optionalProfiler);
+            }
+
             CompletionQueueEvent ev;
             do
             {
diff --git a/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs b/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
index dc9f62fdab..05dda5b148 100644
--- a/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
@@ -48,22 +48,19 @@ namespace Grpc.Core.Internal
             
         public static MetadataArraySafeHandle Create(Metadata metadata)
         {
-            using (Profilers.ForCurrentThread().NewScope("MetadataArraySafeHandle.Create"))
+            if (metadata.Count == 0)
             {
-                if (metadata.Count == 0)
-                {
-                    return new MetadataArraySafeHandle();
-                }
+                return new MetadataArraySafeHandle();
+            }
 
-                // TODO(jtattermusch): we might wanna check that the metadata is readonly 
-                var metadataArray = Native.grpcsharp_metadata_array_create(new UIntPtr((ulong)metadata.Count));
-                for (int i = 0; i < metadata.Count; i++)
-                {
-                    var valueBytes = metadata[i].GetSerializedValueUnsafe();
-                    Native.grpcsharp_metadata_array_add(metadataArray, metadata[i].Key, valueBytes, new UIntPtr((ulong)valueBytes.Length));
-                }
-                return metadataArray;
+            // TODO(jtattermusch): we might wanna check that the metadata is readonly
+            var metadataArray = Native.grpcsharp_metadata_array_create(new UIntPtr((ulong)metadata.Count));
+            for (int i = 0; i < metadata.Count; i++)
+            {
+                var valueBytes = metadata[i].GetSerializedValueUnsafe();
+                Native.grpcsharp_metadata_array_add(metadataArray, metadata[i].Key, valueBytes, new UIntPtr((ulong)valueBytes.Length));
             }
+            return metadataArray;
         }
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core/Profiling/Profilers.cs b/src/csharp/Grpc.Core/Profiling/Profilers.cs
index aa0d96c0e0..6afabff6a7 100644
--- a/src/csharp/Grpc.Core/Profiling/Profilers.cs
+++ b/src/csharp/Grpc.Core/Profiling/Profilers.cs
@@ -80,7 +80,7 @@ namespace Grpc.Core.Profiling
         ProfilerEntry[] entries;
         int count;
 
-        public BasicProfiler() : this(1024*1024)
+        public BasicProfiler() : this(20*1024*1024)
         {
         }
 
diff --git a/src/csharp/Grpc.IntegrationTesting/MetadataCredentialsTest.cs b/src/csharp/Grpc.IntegrationTesting/MetadataCredentialsTest.cs
index eb3bb8a28b..d55e658d94 100644
--- a/src/csharp/Grpc.IntegrationTesting/MetadataCredentialsTest.cs
+++ b/src/csharp/Grpc.IntegrationTesting/MetadataCredentialsTest.cs
@@ -103,6 +103,34 @@ namespace Grpc.IntegrationTesting
             client.UnaryCall(new SimpleRequest { }, new CallOptions(credentials: callCredentials));
         }
 
+        [Test]
+        public void MetadataCredentials_InterceptorLeavesMetadataEmpty()
+        {
+            var channelCredentials = ChannelCredentials.Create(TestCredentials.CreateSslCredentials(),
+                CallCredentials.FromInterceptor(new AsyncAuthInterceptor((context, metadata) => TaskUtils.CompletedTask)));
+            channel = new Channel(Host, server.Ports.Single().BoundPort, channelCredentials, options);
+            client = new TestService.TestServiceClient(channel);
+
+            var ex = Assert.Throws<RpcException>(() => client.UnaryCall(new SimpleRequest { }));
+            // StatusCode.Unknown as the server-side handler throws an exception after not receiving the authorization header.
+            Assert.AreEqual(StatusCode.Unknown, ex.Status.StatusCode);
+        }
+
+        [Test]
+        public void MetadataCredentials_InterceptorThrows()
+        {
+            var callCredentials = CallCredentials.FromInterceptor(new AsyncAuthInterceptor((context, metadata) =>
+            {
+                throw new Exception("Auth interceptor throws");
+            }));
+            var channelCredentials = ChannelCredentials.Create(TestCredentials.CreateSslCredentials(), callCredentials);
+            channel = new Channel(Host, server.Ports.Single().BoundPort, channelCredentials, options);
+            client = new TestService.TestServiceClient(channel);
+
+            var ex = Assert.Throws<RpcException>(() => client.UnaryCall(new SimpleRequest { }));
+            Assert.AreEqual(StatusCode.Unauthenticated, ex.Status.StatusCode);
+        }
+
         private class FakeTestService : TestService.TestServiceBase
         {
             public override Task<SimpleResponse> UnaryCall(SimpleRequest request, ServerCallContext context)
diff --git a/src/csharp/ext/grpc_csharp_ext.c b/src/csharp/ext/grpc_csharp_ext.c
index 0bf5b0acf3..37d04eb100 100644
--- a/src/csharp/ext/grpc_csharp_ext.c
+++ b/src/csharp/ext/grpc_csharp_ext.c
@@ -991,7 +991,11 @@ GPR_EXPORT void GPR_CALLTYPE grpcsharp_metadata_credentials_notify_from_plugin(
     grpc_credentials_plugin_metadata_cb cb,
     void *user_data, grpc_metadata_array *metadata,
   grpc_status_code status, const char *error_details) {
-  cb(user_data, metadata->metadata, metadata->count, status, error_details);
+  if (metadata) {
+    cb(user_data, metadata->metadata, metadata->count, status, error_details);
+  } else {
+    cb(user_data, NULL, 0, status, error_details);
+  }
 }
 
 typedef void(GPR_CALLTYPE *grpcsharp_metadata_interceptor_func)(
diff --git a/src/node/ext/byte_buffer.cc b/src/node/ext/byte_buffer.cc
index 017d7962c3..fc339fc462 100644
--- a/src/node/ext/byte_buffer.cc
+++ b/src/node/ext/byte_buffer.cc
@@ -37,7 +37,7 @@
 #include <nan.h>
 #include "grpc/grpc.h"
 #include "grpc/byte_buffer_reader.h"
-#include "grpc/support/slice.h"
+#include "grpc/slice.h"
 
 #include "byte_buffer.h"
 
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index b0041871d4..8fe36d98a3 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -121,6 +121,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/resolve_address_windows.c',
   'src/core/lib/iomgr/resource_quota.c',
   'src/core/lib/iomgr/sockaddr_utils.c',
+  'src/core/lib/iomgr/socket_mutator.c',
   'src/core/lib/iomgr/socket_utils_common_posix.c',
   'src/core/lib/iomgr/socket_utils_linux.c',
   'src/core/lib/iomgr/socket_utils_posix.c',
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index 7a64c1431d..b137700aa6 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -686,7 +686,7 @@ extern gpr_join_host_port_type gpr_join_host_port_import;
 typedef int(*gpr_split_host_port_type)(const char *name, char **host, char **port);
 extern gpr_split_host_port_type gpr_split_host_port_import;
 #define gpr_split_host_port gpr_split_host_port_import
-typedef void(*gpr_log_type)(const char *file, int line, gpr_log_severity severity, const char *format, ...) GPRC_PRINT_FORMAT_CHECK(4, 5);
+typedef void(*gpr_log_type)(const char *file, int line, gpr_log_severity severity, const char *format, ...) GPR_PRINT_FORMAT_CHECK(4, 5);
 extern gpr_log_type gpr_log_import;
 #define gpr_log gpr_log_import
 typedef void(*gpr_log_message_type)(const char *file, int line, gpr_log_severity severity, const char *message);
@@ -707,7 +707,7 @@ extern gpr_format_message_type gpr_format_message_import;
 typedef char *(*gpr_strdup_type)(const char *src);
 extern gpr_strdup_type gpr_strdup_import;
 #define gpr_strdup gpr_strdup_import
-typedef int(*gpr_asprintf_type)(char **strp, const char *format, ...) GPRC_PRINT_FORMAT_CHECK(2, 3);
+typedef int(*gpr_asprintf_type)(char **strp, const char *format, ...) GPR_PRINT_FORMAT_CHECK(2, 3);
 extern gpr_asprintf_type gpr_asprintf_import;
 #define gpr_asprintf gpr_asprintf_import
 typedef const char *(*gpr_subprocess_binary_extension_type)();