diff --git a/README.md b/README.md
index e9b0454871c..70cf9fcc30e 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ See [tools/run_tests](tools/run_tests) for more guidance on how to run various t
 
 This repository contains source code for gRPC libraries for multiple languages written on top of shared C core library [src/core] (src/core).
 
-Libraries in different languages are in different states of development. We are seeking contributions for all of these libraries.
+Libraries in different languages may be in different states of development. We are seeking contributions for all of these libraries.
 
 | Language                | Source                              | Status  |
 |-------------------------|-------------------------------------|---------|
diff --git a/src/compiler/README.md b/src/compiler/README.md
new file mode 100644
index 00000000000..a2f49b3cd53
--- /dev/null
+++ b/src/compiler/README.md
@@ -0,0 +1,4 @@
+#Overview
+
+This directory contains source code for gRPC protocol buffer compiler (*protoc*) plugins. Along with `protoc`,
+these plugins are used to generate gRPC client and server stubs from `.proto` files.
diff --git a/src/core/README.md b/src/core/README.md
index 0d8c0d5bd90..44c6f247725 100644
--- a/src/core/README.md
+++ b/src/core/README.md
@@ -1,8 +1,4 @@
 #Overview
 
-This directory contains source code for shared C library. Libraries in other languages in this repository (C++, Ruby,
+This directory contains source code for C library (a.k.a the *gRPC C core*) that provides all gRPC's core functionality through a low level API. Libraries in other languages in this repository (C++, Ruby,
 Python, PHP, NodeJS, Objective-C) are layered on top of this library.
-
-#Status
-
-Beta
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index ae1f2a3b4c6..626f285b90a 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -329,8 +329,8 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx,
   if (server->port >> 16 != 0) {
     if (log) {
       gpr_log(GPR_ERROR,
-              "Invalid port '%d' at index %zu of serverlist. Ignoring.",
-              server->port, idx);
+              "Invalid port '%d' at index %lu of serverlist. Ignoring.",
+              server->port, (unsigned long)idx);
     }
     return false;
   }
@@ -338,9 +338,9 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx,
   if (ip->size != 4 && ip->size != 16) {
     if (log) {
       gpr_log(GPR_ERROR,
-              "Expected IP to be 4 or 16 bytes, got %d at index %zu of "
+              "Expected IP to be 4 or 16 bytes, got %d at index %lu of "
               "serverlist. Ignoring",
-              ip->size, idx);
+              ip->size, (unsigned long)idx);
     }
     return false;
   }
@@ -1070,8 +1070,8 @@ static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
     if (serverlist != NULL) {
       gpr_slice_unref(response_slice);
       if (grpc_lb_glb_trace) {
-        gpr_log(GPR_INFO, "Serverlist with %zu servers received",
-                serverlist->num_servers);
+        gpr_log(GPR_INFO, "Serverlist with %lu servers received",
+                (unsigned long)serverlist->num_servers);
       }
 
       /* update serverlist */
@@ -1155,10 +1155,10 @@ static void srv_status_rcvd_cb(grpc_exec_ctx *exec_ctx, void *arg,
   if (grpc_lb_glb_trace) {
     gpr_log(GPR_INFO,
             "status from lb server received. Status = %d, Details = '%s', "
-            "Capaticy "
-            "= %zu",
+            "Capacity "
+            "= %lu",
             lb_client->status, lb_client->status_details,
-            lb_client->status_details_capacity);
+            (unsigned long)lb_client->status_details_capacity);
   }
   /* TODO(dgq): deal with stream termination properly (fire up another one?
    * fail the original call?) */
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
index da3e284fcf2..563271f4f8c 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
@@ -61,13 +61,12 @@ typedef struct server_secure_state {
   grpc_server_credentials *creds;
   bool is_shutdown;
   gpr_mu mu;
-  gpr_refcount refcount;
-  grpc_closure destroy_closure;
-  grpc_closure *destroy_callback;
+  grpc_closure tcp_server_shutdown_complete;
+  grpc_closure *server_destroy_listener_done;
 } server_secure_state;
 
 typedef struct server_secure_connect {
-  server_secure_state *state;
+  server_secure_state *server_state;
   grpc_pollset *accepting_pollset;
   grpc_tcp_server_acceptor *acceptor;
   grpc_handshake_manager *handshake_mgr;
@@ -77,39 +76,28 @@ typedef struct server_secure_connect {
   grpc_channel_args *args;
 } server_secure_connect;
 
-static void state_ref(server_secure_state *state) { gpr_ref(&state->refcount); }
-
-static void state_unref(server_secure_state *state) {
-  if (gpr_unref(&state->refcount)) {
-    /* ensure all threads have unlocked */
-    gpr_mu_lock(&state->mu);
-    gpr_mu_unlock(&state->mu);
-    /* clean up */
-    GRPC_SECURITY_CONNECTOR_UNREF(&state->sc->base, "server");
-    grpc_server_credentials_unref(state->creds);
-    gpr_free(state);
-  }
-}
-
 static void on_secure_handshake_done(grpc_exec_ctx *exec_ctx, void *statep,
                                      grpc_security_status status,
                                      grpc_endpoint *secure_endpoint,
                                      grpc_auth_context *auth_context) {
-  server_secure_connect *state = statep;
+  server_secure_connect *connection_state = statep;
   if (status == GRPC_SECURITY_OK) {
     if (secure_endpoint) {
-      gpr_mu_lock(&state->state->mu);
-      if (!state->state->is_shutdown) {
+      gpr_mu_lock(&connection_state->server_state->mu);
+      if (!connection_state->server_state->is_shutdown) {
         grpc_transport *transport = grpc_create_chttp2_transport(
-            exec_ctx, grpc_server_get_channel_args(state->state->server),
+            exec_ctx, grpc_server_get_channel_args(
+                          connection_state->server_state->server),
             secure_endpoint, 0);
         grpc_arg args_to_add[2];
-        args_to_add[0] = grpc_server_credentials_to_arg(state->state->creds);
+        args_to_add[0] = grpc_server_credentials_to_arg(
+            connection_state->server_state->creds);
         args_to_add[1] = grpc_auth_context_to_arg(auth_context);
         grpc_channel_args *args_copy = grpc_channel_args_copy_and_add(
-            state->args, args_to_add, GPR_ARRAY_SIZE(args_to_add));
-        grpc_server_setup_transport(exec_ctx, state->state->server, transport,
-                                    state->accepting_pollset, args_copy);
+            connection_state->args, args_to_add, GPR_ARRAY_SIZE(args_to_add));
+        grpc_server_setup_transport(
+            exec_ctx, connection_state->server_state->server, transport,
+            connection_state->accepting_pollset, args_copy);
         grpc_channel_args_destroy(args_copy);
         grpc_chttp2_transport_start_reading(exec_ctx, transport, NULL);
       } else {
@@ -117,21 +105,21 @@ static void on_secure_handshake_done(grpc_exec_ctx *exec_ctx, void *statep,
          * gone away. */
         grpc_endpoint_destroy(exec_ctx, secure_endpoint);
       }
-      gpr_mu_unlock(&state->state->mu);
+      gpr_mu_unlock(&connection_state->server_state->mu);
     }
   } else {
     gpr_log(GPR_ERROR, "Secure transport failed with error %d", status);
   }
-  grpc_channel_args_destroy(state->args);
-  state_unref(state->state);
-  gpr_free(state);
+  grpc_channel_args_destroy(connection_state->args);
+  grpc_tcp_server_unref(exec_ctx, connection_state->server_state->tcp);
+  gpr_free(connection_state);
 }
 
 static void on_handshake_done(grpc_exec_ctx *exec_ctx, grpc_endpoint *endpoint,
                               grpc_channel_args *args,
                               gpr_slice_buffer *read_buffer, void *user_data,
                               grpc_error *error) {
-  server_secure_connect *state = user_data;
+  server_secure_connect *connection_state = user_data;
   if (error != GRPC_ERROR_NONE) {
     const char *error_str = grpc_error_string(error);
     gpr_log(GPR_ERROR, "Handshaking failed: %s", error_str);
@@ -139,81 +127,107 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, grpc_endpoint *endpoint,
     GRPC_ERROR_UNREF(error);
     grpc_channel_args_destroy(args);
     gpr_free(read_buffer);
-    grpc_handshake_manager_shutdown(exec_ctx, state->handshake_mgr);
-    grpc_handshake_manager_destroy(exec_ctx, state->handshake_mgr);
-    state_unref(state->state);
-    gpr_free(state);
+    grpc_handshake_manager_shutdown(exec_ctx, connection_state->handshake_mgr);
+    grpc_handshake_manager_destroy(exec_ctx, connection_state->handshake_mgr);
+    grpc_tcp_server_unref(exec_ctx, connection_state->server_state->tcp);
+    gpr_free(connection_state);
     return;
   }
-  grpc_handshake_manager_destroy(exec_ctx, state->handshake_mgr);
-  state->handshake_mgr = NULL;
+  grpc_handshake_manager_destroy(exec_ctx, connection_state->handshake_mgr);
+  connection_state->handshake_mgr = NULL;
   // TODO(roth, jboeuf): Convert security connector handshaking to use new
   // handshake API, and then move the code from on_secure_handshake_done()
   // into this function.
-  state->args = args;
+  connection_state->args = args;
   grpc_server_security_connector_do_handshake(
-      exec_ctx, state->state->sc, state->acceptor, endpoint, read_buffer,
-      state->deadline, on_secure_handshake_done, state);
+      exec_ctx, connection_state->server_state->sc, connection_state->acceptor,
+      endpoint, read_buffer, connection_state->deadline,
+      on_secure_handshake_done, connection_state);
 }
 
 static void on_accept(grpc_exec_ctx *exec_ctx, void *statep, grpc_endpoint *tcp,
                       grpc_pollset *accepting_pollset,
                       grpc_tcp_server_acceptor *acceptor) {
-  server_secure_connect *state = gpr_malloc(sizeof(*state));
-  state->state = statep;
-  state_ref(state->state);
-  state->accepting_pollset = accepting_pollset;
-  state->acceptor = acceptor;
-  state->handshake_mgr = grpc_handshake_manager_create();
+  server_secure_state *server_state = statep;
+  server_secure_connect *connection_state = NULL;
+  gpr_mu_lock(&server_state->mu);
+  if (server_state->is_shutdown) {
+    gpr_mu_unlock(&server_state->mu);
+    grpc_endpoint_destroy(exec_ctx, tcp);
+    return;
+  }
+  gpr_mu_unlock(&server_state->mu);
+  grpc_tcp_server_ref(server_state->tcp);
+  connection_state = gpr_malloc(sizeof(*connection_state));
+  connection_state->server_state = server_state;
+  connection_state->accepting_pollset = accepting_pollset;
+  connection_state->acceptor = acceptor;
+  connection_state->handshake_mgr = grpc_handshake_manager_create();
   // TODO(roth): We should really get this timeout value from channel
   // args instead of hard-coding it.
-  state->deadline = gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                                 gpr_time_from_seconds(120, GPR_TIMESPAN));
+  connection_state->deadline = gpr_time_add(
+      gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_seconds(120, GPR_TIMESPAN));
   grpc_handshake_manager_do_handshake(
-      exec_ctx, state->handshake_mgr, tcp,
-      grpc_server_get_channel_args(state->state->server), state->deadline,
-      acceptor, on_handshake_done, state);
+      exec_ctx, connection_state->handshake_mgr, tcp,
+      grpc_server_get_channel_args(connection_state->server_state->server),
+      connection_state->deadline, acceptor, on_handshake_done,
+      connection_state);
 }
 
 /* Server callback: start listening on our ports */
-static void start(grpc_exec_ctx *exec_ctx, grpc_server *server, void *statep,
-                  grpc_pollset **pollsets, size_t pollset_count) {
-  server_secure_state *state = statep;
-  grpc_tcp_server_start(exec_ctx, state->tcp, pollsets, pollset_count,
-                        on_accept, state);
+static void server_start_listener(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                                  void *statep, grpc_pollset **pollsets,
+                                  size_t pollset_count) {
+  server_secure_state *server_state = statep;
+  gpr_mu_lock(&server_state->mu);
+  server_state->is_shutdown = false;
+  gpr_mu_unlock(&server_state->mu);
+  grpc_tcp_server_start(exec_ctx, server_state->tcp, pollsets, pollset_count,
+                        on_accept, server_state);
 }
 
-static void destroy_done(grpc_exec_ctx *exec_ctx, void *statep,
-                         grpc_error *error) {
-  server_secure_state *state = statep;
-  if (state->destroy_callback != NULL) {
-    state->destroy_callback->cb(exec_ctx, state->destroy_callback->cb_arg,
-                                GRPC_ERROR_REF(error));
+static void tcp_server_shutdown_complete(grpc_exec_ctx *exec_ctx, void *statep,
+                                         grpc_error *error) {
+  server_secure_state *server_state = statep;
+  /* ensure all threads have unlocked */
+  gpr_mu_lock(&server_state->mu);
+  grpc_closure *destroy_done = server_state->server_destroy_listener_done;
+  GPR_ASSERT(server_state->is_shutdown);
+  gpr_mu_unlock(&server_state->mu);
+  /* clean up */
+  grpc_server_security_connector_shutdown(exec_ctx, server_state->sc);
+
+  /* Flush queued work before a synchronous unref. */
+  grpc_exec_ctx_flush(exec_ctx);
+  GRPC_SECURITY_CONNECTOR_UNREF(&server_state->sc->base, "server");
+  grpc_server_credentials_unref(server_state->creds);
+
+  if (destroy_done != NULL) {
+    destroy_done->cb(exec_ctx, destroy_done->cb_arg, GRPC_ERROR_REF(error));
+    grpc_exec_ctx_flush(exec_ctx);
   }
-  grpc_server_security_connector_shutdown(exec_ctx, state->sc);
-  state_unref(state);
+  gpr_free(server_state);
 }
 
-/* Server callback: destroy the tcp listener (so we don't generate further
-   callbacks) */
-static void destroy(grpc_exec_ctx *exec_ctx, grpc_server *server, void *statep,
-                    grpc_closure *callback) {
-  server_secure_state *state = statep;
+static void server_destroy_listener(grpc_exec_ctx *exec_ctx,
+                                    grpc_server *server, void *statep,
+                                    grpc_closure *callback) {
+  server_secure_state *server_state = statep;
   grpc_tcp_server *tcp;
-  gpr_mu_lock(&state->mu);
-  state->is_shutdown = true;
-  state->destroy_callback = callback;
-  tcp = state->tcp;
-  gpr_mu_unlock(&state->mu);
+  gpr_mu_lock(&server_state->mu);
+  server_state->is_shutdown = true;
+  server_state->server_destroy_listener_done = callback;
+  tcp = server_state->tcp;
+  gpr_mu_unlock(&server_state->mu);
   grpc_tcp_server_shutdown_listeners(exec_ctx, tcp);
-  grpc_tcp_server_unref(exec_ctx, tcp);
+  grpc_tcp_server_unref(exec_ctx, server_state->tcp);
 }
 
 int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
                                       grpc_server_credentials *creds) {
   grpc_resolved_addresses *resolved = NULL;
   grpc_tcp_server *tcp = NULL;
-  server_secure_state *state = NULL;
+  server_secure_state *server_state = NULL;
   size_t i;
   size_t count = 0;
   int port_num = -1;
@@ -253,22 +267,22 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   if (err != GRPC_ERROR_NONE) {
     goto error;
   }
-  state = gpr_malloc(sizeof(*state));
-  memset(state, 0, sizeof(*state));
-  grpc_closure_init(&state->destroy_closure, destroy_done, state);
-  err = grpc_tcp_server_create(&state->destroy_closure,
+  server_state = gpr_malloc(sizeof(*server_state));
+  memset(server_state, 0, sizeof(*server_state));
+  grpc_closure_init(&server_state->tcp_server_shutdown_complete,
+                    tcp_server_shutdown_complete, server_state);
+  err = grpc_tcp_server_create(&server_state->tcp_server_shutdown_complete,
                                grpc_server_get_channel_args(server), &tcp);
   if (err != GRPC_ERROR_NONE) {
     goto error;
   }
 
-  state->server = server;
-  state->tcp = tcp;
-  state->sc = sc;
-  state->creds = grpc_server_credentials_ref(creds);
-  state->is_shutdown = false;
-  gpr_mu_init(&state->mu);
-  gpr_ref_init(&state->refcount, 1);
+  server_state->server = server;
+  server_state->tcp = tcp;
+  server_state->sc = sc;
+  server_state->creds = grpc_server_credentials_ref(creds);
+  server_state->is_shutdown = true;
+  gpr_mu_init(&server_state->mu);
 
   errors = gpr_malloc(sizeof(*errors) * resolved->naddrs);
   for (i = 0; i < resolved->naddrs; i++) {
@@ -313,7 +327,8 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   grpc_resolved_addresses_destroy(resolved);
 
   /* Register with the server only upon success */
-  grpc_server_add_listener(&exec_ctx, server, state, start, destroy);
+  grpc_server_add_listener(&exec_ctx, server, server_state,
+                           server_start_listener, server_destroy_listener);
 
   grpc_exec_ctx_finish(&exec_ctx);
   return port_num;
@@ -334,10 +349,11 @@ error:
     grpc_tcp_server_unref(&exec_ctx, tcp);
   } else {
     if (sc) {
+      grpc_exec_ctx_flush(&exec_ctx);
       GRPC_SECURITY_CONNECTOR_UNREF(&sc->base, "server");
     }
-    if (state) {
-      gpr_free(state);
+    if (server_state) {
+      gpr_free(server_state);
     }
   }
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 5a25d39a0c4..9a390699b45 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -101,8 +101,8 @@ grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s);
 void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
                                            grpc_closure *shutdown_starting);
 
-/* If the refcount drops to zero, delete s, and call (exec_ctx==NULL) or enqueue
-   a call (exec_ctx!=NULL) to shutdown_complete. */
+/* If the refcount drops to zero, enqueue calls on exec_ctx to
+   shutdown_listeners and delete s. */
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s);
 
 /* Shutdown the fds of listeners. */
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 2d3f6cf9a7d..73df5477e66 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -191,6 +191,9 @@ grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
 }
 
 static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  gpr_mu_lock(&s->mu);
+  GPR_ASSERT(s->shutdown);
+  gpr_mu_unlock(&s->mu);
   if (s->shutdown_complete != NULL) {
     grpc_exec_ctx_sched(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE, NULL);
   }
@@ -652,6 +655,7 @@ unsigned grpc_tcp_server_port_fd_count(grpc_tcp_server *s,
                                        unsigned port_index) {
   unsigned num_fds = 0;
   grpc_tcp_listener *sp;
+  gpr_mu_lock(&s->mu);
   for (sp = s->head; sp && port_index != 0; sp = sp->next) {
     if (!sp->is_sibling) {
       --port_index;
@@ -659,12 +663,15 @@ unsigned grpc_tcp_server_port_fd_count(grpc_tcp_server *s,
   }
   for (; sp; sp = sp->sibling, ++num_fds)
     ;
+  gpr_mu_unlock(&s->mu);
   return num_fds;
 }
 
 int grpc_tcp_server_port_fd(grpc_tcp_server *s, unsigned port_index,
                             unsigned fd_index) {
   grpc_tcp_listener *sp;
+  int fd;
+  gpr_mu_lock(&s->mu);
   for (sp = s->head; sp && port_index != 0; sp = sp->next) {
     if (!sp->is_sibling) {
       --port_index;
@@ -673,10 +680,12 @@ int grpc_tcp_server_port_fd(grpc_tcp_server *s, unsigned port_index,
   for (; sp && fd_index != 0; sp = sp->sibling, --fd_index)
     ;
   if (sp) {
-    return sp->fd;
+    fd = sp->fd;
   } else {
-    return -1;
+    fd = -1;
   }
+  gpr_mu_unlock(&s->mu);
+  return fd;
 }
 
 void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
@@ -722,7 +731,7 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 }
 
 grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
-  gpr_ref(&s->refs);
+  gpr_ref_non_zero(&s->refs);
   return s;
 }
 
@@ -736,19 +745,11 @@ void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
 
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (gpr_unref(&s->refs)) {
-    /* Complete shutdown_starting work before destroying. */
-    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_tcp_server_shutdown_listeners(exec_ctx, s);
     gpr_mu_lock(&s->mu);
-    grpc_exec_ctx_enqueue_list(&local_exec_ctx, &s->shutdown_starting, NULL);
+    grpc_exec_ctx_enqueue_list(exec_ctx, &s->shutdown_starting, NULL);
     gpr_mu_unlock(&s->mu);
-    if (exec_ctx == NULL) {
-      grpc_exec_ctx_flush(&local_exec_ctx);
-      tcp_server_destroy(&local_exec_ctx, s);
-      grpc_exec_ctx_finish(&local_exec_ctx);
-    } else {
-      grpc_exec_ctx_finish(&local_exec_ctx);
-      tcp_server_destroy(exec_ctx, s);
-    }
+    tcp_server_destroy(exec_ctx, s);
   }
 }
 
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index 1b125e7005b..4ff05601fa8 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -139,7 +139,7 @@ static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 }
 
 grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
-  gpr_ref(&s->refs);
+  gpr_ref_non_zero(&s->refs);
   return s;
 }
 
@@ -174,19 +174,11 @@ static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (gpr_unref(&s->refs)) {
-    /* Complete shutdown_starting work before destroying. */
-    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_tcp_server_shutdown_listeners(exec_ctx, s);
     gpr_mu_lock(&s->mu);
-    grpc_exec_ctx_enqueue_list(&local_exec_ctx, &s->shutdown_starting, NULL);
+    grpc_exec_ctx_enqueue_list(exec_ctx, &s->shutdown_starting, NULL);
     gpr_mu_unlock(&s->mu);
-    if (exec_ctx == NULL) {
-      grpc_exec_ctx_flush(&local_exec_ctx);
-      tcp_server_destroy(&local_exec_ctx, s);
-      grpc_exec_ctx_finish(&local_exec_ctx);
-    } else {
-      grpc_exec_ctx_finish(&local_exec_ctx);
-      tcp_server_destroy(exec_ctx, s);
-    }
+    tcp_server_destroy(exec_ctx, s);
   }
 }
 
diff --git a/src/cpp/README.md b/src/cpp/README.md
index 8c0f85e5ff7..d9b521317a6 100644
--- a/src/cpp/README.md
+++ b/src/cpp/README.md
@@ -3,10 +3,6 @@
 
 This directory contains source code for C++ implementation of gRPC.
 
-#Status
-
-Beta
-
 #Pre-requisites
 
 ##Linux
diff --git a/src/csharp/README.md b/src/csharp/README.md
index 18d5945a8a1..0405ff88a01 100644
--- a/src/csharp/README.md
+++ b/src/csharp/README.md
@@ -4,10 +4,13 @@ gRPC C#
 
 A C# implementation of gRPC.
 
-Status
-------
+SUPPORTED PLATFORMS
+------------------
+
+- .NET Framework 4.5+ (Windows)
+- [.NET Core](https://dotnet.github.io/) on Linux, Windows and Mac OS X (starting from version 1.0.1)
+- Mono 4+ on Linux, Windows and Mac OS X
 
-Beta
 
 PREREQUISITES
 --------------
@@ -16,6 +19,7 @@ PREREQUISITES
 - Linux: Mono 4+, MonoDevelop 5.9+ (with NuGet add-in installed)
 - Mac OS X: Xamarin Studio 5.9+
 
+
 HOW TO USE
 --------------
 
@@ -69,12 +73,6 @@ different languages.
 tools/run_tests/run_tests.py -l csharp
 ```
 
-ON .NET CORE SUPPORT
-------------------
-
-We are committed to providing full support for [.NET Core](https://dotnet.github.io/) in near future,
-but currently, the support is for .NET Core is experimental/work-in-progress.
-
 DOCUMENTATION
 -------------
 - [API Reference][]
@@ -102,9 +100,7 @@ CONTENTS
 THE NATIVE DEPENDENCY
 ---------------
 
-Internally, gRPC C# uses a native library written in C (gRPC C core) and invokes its functionality via P/Invoke. `grpc_csharp_ext` library is a native extension library that facilitates this by wrapping some C core API into a form that's more digestible for P/Invoke.
-
-Prior to version 0.13, installing `grpc_csharp_ext` was required to make gRPC work on Linux and MacOS. Starting with version 0.13, we have improved the packaging story significantly and precompiled versions of the native library for all supported platforms are now shipped with the NuGet package. Just installing the `Grpc` NuGet package should be the only step needed to use gRPC C#, regardless of your platform (Windows, Linux or Mac) and the bitness (32 or 64bit).
+Internally, gRPC C# uses a native library written in C (gRPC C core) and invokes its functionality via P/Invoke. The fact that a native library is used should be fully transparent to the users and just installing the `Grpc.Core` NuGet package is the only step needed to use gRPC C# on all supported platforms.
 
 [API Reference]: http://www.grpc.io/grpc/csharp/
 [Helloworld Example]: ../../examples/csharp/helloworld
diff --git a/src/node/README.md b/src/node/README.md
index 9eafce92435..4b906643bc0 100644
--- a/src/node/README.md
+++ b/src/node/README.md
@@ -1,9 +1,6 @@
 [![npm](https://img.shields.io/npm/v/grpc.svg)](https://www.npmjs.com/package/grpc)
 # Node.js gRPC Library
 
-## Status
-Beta
-
 ## PREREQUISITES
 - `node`: This requires `node` to be installed, version `0.12` or above. If you instead have the `nodejs` executable on Debian, you should install the [`nodejs-legacy`](https://packages.debian.org/sid/nodejs-legacy) package.
 
diff --git a/src/php/README.md b/src/php/README.md
index 0e5b4de31e3..1b15768d44a 100644
--- a/src/php/README.md
+++ b/src/php/README.md
@@ -4,10 +4,6 @@
 This directory contains source code for PHP implementation of gRPC layered on
 shared C library.
 
-#Status
-
-GA
-
 ## Environment
 
 **Prerequisite:**
diff --git a/src/ruby/README.md b/src/ruby/README.md
index 67e94dd3540..f476fe72be2 100644
--- a/src/ruby/README.md
+++ b/src/ruby/README.md
@@ -4,11 +4,6 @@ gRPC Ruby
 
 A Ruby implementation of gRPC.
 
-Status
-------
-
-Beta
-
 PREREQUISITES
 -------------
 
diff --git a/templates/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile.template b/templates/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile.template
index b6a3b0d5d21..5c38e9a0e92 100644
--- a/templates/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile.template
+++ b/templates/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile.template
@@ -41,6 +41,12 @@
     g++-4.4 ${'\\'}
     g++-4.4-multilib
 
+  # set up backport to allow installation of Git version > 1.7
+  RUN echo "deb http://http.debian.net/debian wheezy-backports main" \
+    >/etc/apt/sources.list.d/wheezy-backports.list
+  RUN apt-get update -qq
+  RUN apt-get -t wheezy-backports install -qq git
+  
   RUN wget ${openssl_fallback.base_uri + openssl_fallback.tarball}
 
   ENV POST_GIT_STEP tools/dockerfile/test/cxx_wheezy_x64/post-git-setup.sh
diff --git a/test/core/iomgr/tcp_server_posix_test.c b/test/core/iomgr/tcp_server_posix_test.c
index 6e2d1d0fc9e..6b1dd428a13 100644
--- a/test/core/iomgr/tcp_server_posix_test.c
+++ b/test/core/iomgr/tcp_server_posix_test.c
@@ -314,11 +314,10 @@ static void test_connect(unsigned n) {
   GPR_ASSERT(grpc_tcp_server_port_fd(s, 0, 0) >= 0);
 
   grpc_tcp_server_unref(&exec_ctx, s);
+  grpc_exec_ctx_finish(&exec_ctx);
 
   /* Weak ref lost. */
   GPR_ASSERT(weak_ref.server == NULL);
-
-  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void destroy_pollset(grpc_exec_ctx *exec_ctx, void *p,
diff --git a/test/core/iomgr/udp_server_test.c b/test/core/iomgr/udp_server_test.c
index 2a304275043..71d2fb5bd44 100644
--- a/test/core/iomgr/udp_server_test.c
+++ b/test/core/iomgr/udp_server_test.c
@@ -131,8 +131,9 @@ static void test_no_op_with_port_and_start(void) {
   grpc_udp_server_destroy(&exec_ctx, s, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
 
-  /* The server had a single FD, which should have been orphaned. */
-  GPR_ASSERT(g_number_of_orphan_calls == 1);
+  /* The server had a single FD, which is orphaned once in *
+   * deactivated_all_ports, and once in grpc_udp_server_destroy. */
+  GPR_ASSERT(g_number_of_orphan_calls == 2);
 }
 
 static void test_receive(int number_of_clients) {
@@ -196,8 +197,9 @@ static void test_receive(int number_of_clients) {
   grpc_udp_server_destroy(&exec_ctx, s, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
 
-  /* The server had a single FD, which should have been orphaned. */
-  GPR_ASSERT(g_number_of_orphan_calls == 1);
+  /* The server had a single FD, which is orphaned once in *
+   * deactivated_all_ports, and once in grpc_udp_server_destroy. */
+  GPR_ASSERT(g_number_of_orphan_calls == 2);
 }
 
 static void destroy_pollset(grpc_exec_ctx *exec_ctx, void *p,
diff --git a/test/distrib/cpp/run_distrib_test.sh b/test/distrib/cpp/run_distrib_test.sh
index bc84b84b8f3..15fbf281074 100755
--- a/test/distrib/cpp/run_distrib_test.sh
+++ b/test/distrib/cpp/run_distrib_test.sh
@@ -30,7 +30,12 @@
 
 set -ex
 
-git clone --recursive $EXTERNAL_GIT_ROOT
+git clone $EXTERNAL_GIT_ROOT
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd ${EXTERNAL_GIT_ROOT} && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference ${EXTERNAL_GIT_ROOT}/${name} \
+${name}')
+
 cd grpc
 
 cd third_party/protobuf && ./autogen.sh && \
diff --git a/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh b/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
index 62e41755ec1..9db7aae9eba 100755
--- a/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
+++ b/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
@@ -31,7 +31,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 cd /var/local/git/grpc
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
index fd5436c44ff..e37070904d3 100755
--- a/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
index 77cd65cce37..d90c899569f 100755
--- a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
index 1c0828d23a6..7a7ca0d3d1c 100755
--- a/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
index 46ddaf929a8..a1d668d69fc 100755
--- a/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
index 976f55d9ab5..4116f842ff1 100755
--- a/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
index 624d5877862..d64ec7903fc 100755
--- a/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
@@ -32,7 +32,11 @@
 set -ex
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
index 87cb0fe4b21..fccca4d695b 100755
--- a/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
@@ -32,7 +32,11 @@
 set -ex
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
index f29c59da8e8..a6f8c7bfe6b 100755
--- a/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
index 97b3860f981..6cd2fa2b147 100755
--- a/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
index 1f4bf893cce..345196894ef 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # Copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
index b67b1a1664a..92d1f80fe60 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
index 919d885c178..9e4769cf334 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
@@ -38,7 +38,11 @@ git clone --recursive /var/local/jenkins/grpc-go src/google.golang.org/grpc
 
 # Clone the 'grpc' repo. We just need this for the wrapper scripts under
 # grpc/tools/gcp/stress_tests
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
index d4fdfbbac96..0194860d101 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
@@ -36,7 +36,11 @@ mkdir -p /var/local/git
 git clone --recursive --depth 1 /var/local/jenkins/grpc-java /var/local/git/grpc-java
 
 # grpc repo (for metrics client and for the stress test wrapper scripts)
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # Copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
index 976f55d9ab5..4116f842ff1 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
index a671d1501f8..e3cca085a4d 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
@@ -32,7 +32,11 @@
 set -ex
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
index e65332f2f30..1c7dc2bd577 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
@@ -32,13 +32,16 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
-
 tools/run_tests/run_tests.py -l python -c opt --build_only
 
 # Build c++ interop client
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
index 1b7567d87a6..019f0a44e4c 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
@@ -32,7 +32,11 @@
 set -e
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 # Copy service account keys if available
 cp -r /var/local/jenkins/service_account $HOME || true
diff --git a/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile b/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile
index c25033387f9..f22fcacc139 100644
--- a/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile
+++ b/tools/dockerfile/test/cxx_wheezy_x64/Dockerfile
@@ -89,6 +89,11 @@ RUN apt-get update && apt-get install -y \
   g++-4.4 \
   g++-4.4-multilib
 
+# set up backport to allow installation of Git version > 1.7
+RUN echo "deb http://http.debian.net/debian wheezy-backports main"   >/etc/apt/sources.list.d/wheezy-backports.list
+RUN apt-get update -qq
+RUN apt-get -t wheezy-backports install -qq git
+
 RUN wget https://openssl.org/source/old/1.0.2/openssl-1.0.2f.tar.gz
 
 ENV POST_GIT_STEP tools/dockerfile/test/cxx_wheezy_x64/post-git-setup.sh
diff --git a/tools/run_tests/dockerize/docker_run.sh b/tools/run_tests/dockerize/docker_run.sh
index f04b1cfb55b..ee8d288fb2a 100755
--- a/tools/run_tests/dockerize/docker_run.sh
+++ b/tools/run_tests/dockerize/docker_run.sh
@@ -36,7 +36,11 @@ set -ex
 if [ "$RELATIVE_COPY_PATH" == "" ]
 then
   mkdir -p /var/local/git
-  git clone --recursive "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
+  git clone $EXTERNAL_GIT_ROOT /var/local/git/grpc
+  # clone gRPC submodules, use data from locally cloned submodules where possible
+  (cd ${EXTERNAL_GIT_ROOT} && git submodule foreach 'cd /var/local/git/grpc \
+  && git submodule update --init --reference ${EXTERNAL_GIT_ROOT}/${name} \
+  ${name}')
 else
   mkdir -p "/var/local/git/grpc/$RELATIVE_COPY_PATH"
   cp -r "$EXTERNAL_GIT_ROOT/$RELATIVE_COPY_PATH"/* "/var/local/git/grpc/$RELATIVE_COPY_PATH"
diff --git a/tools/run_tests/dockerize/docker_run_tests.sh b/tools/run_tests/dockerize/docker_run_tests.sh
index ef02d266253..eb220ae416f 100755
--- a/tools/run_tests/dockerize/docker_run_tests.sh
+++ b/tools/run_tests/dockerize/docker_run_tests.sh
@@ -42,7 +42,11 @@ export PATH=$PATH:/usr/bin/llvm-symbolizer
 chown $(whoami) $XDG_CACHE_HOME
 
 mkdir -p /var/local/git
-git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
+git clone  /var/local/jenkins/grpc /var/local/git/grpc
+# clone gRPC submodules, use data from locally cloned submodules where possible
+(cd /var/local/jenkins/grpc/ && git submodule foreach 'cd /var/local/git/grpc \
+&& git submodule update --init --reference /var/local/jenkins/grpc/${name} \
+${name}')
 
 mkdir -p reports