Merge pull request #6973 from makdharma/network_status_change

Network status tracking

5 files changed, 172 insertions, 0 deletions

diff --git a/src/core/lib/iomgr/network_status_tracker.c b/src/core/lib/iomgr/network_status_tracker.c
new file mode 100644
index 0000000000..38a1c9b7d4
--- /dev/null
+++ b/src/core/lib/iomgr/network_status_tracker.c
@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include "src/core/lib/iomgr/endpoint.h"
+
+typedef struct endpoint_ll_node {
+  grpc_endpoint *ep;
+  struct endpoint_ll_node *next;
+} endpoint_ll_node;
+
+static endpoint_ll_node *head = NULL;
+static gpr_mu g_endpoint_mutex;
+static bool g_init_done = false;
+
+void grpc_initialize_network_status_monitor() {
+  g_init_done = true;
+  gpr_mu_init(&g_endpoint_mutex);
+  // TODO(makarandd): Install callback with OS to monitor network status.
+}
+
+void grpc_destroy_network_status_monitor() {
+  for (endpoint_ll_node *curr = head; curr != NULL;) {
+    endpoint_ll_node *next = curr->next;
+    gpr_free(curr);
+    curr = next;
+  }
+  gpr_mu_destroy(&g_endpoint_mutex);
+}
+
+void grpc_network_status_register_endpoint(grpc_endpoint *ep) {
+  if (!g_init_done) {
+    grpc_initialize_network_status_monitor();
+  }
+  gpr_mu_lock(&g_endpoint_mutex);
+  if (head == NULL) {
+    head = (endpoint_ll_node *)gpr_malloc(sizeof(endpoint_ll_node));
+    head->ep = ep;
+    head->next = NULL;
+  } else {
+    endpoint_ll_node *prev_head = head;
+    head = (endpoint_ll_node *)gpr_malloc(sizeof(endpoint_ll_node));
+    head->ep = ep;
+    head->next = prev_head;
+  }
+  gpr_mu_unlock(&g_endpoint_mutex);
+}
+
+void grpc_network_status_unregister_endpoint(grpc_endpoint *ep) {
+  gpr_mu_lock(&g_endpoint_mutex);
+  GPR_ASSERT(head);
+  bool found = false;
+  endpoint_ll_node *prev = head;
+  // if we're unregistering the head, just move head to the next
+  if (ep == head->ep) {
+    head = head->next;
+    gpr_free(prev);
+    found = true;
+  } else {
+    for (endpoint_ll_node *curr = head->next; curr != NULL; curr = curr->next) {
+      if (ep == curr->ep) {
+        prev->next = curr->next;
+        gpr_free(curr);
+        found = true;
+        break;
+      }
+      prev = curr;
+    }
+  }
+  gpr_mu_unlock(&g_endpoint_mutex);
+  GPR_ASSERT(found);
+}
+
+// Walk the linked-list from head and execute shutdown. It is possible that
+// other threads might be in the process of shutdown as well, but that has
+// no side effect since endpoint shutdown is idempotent.
+void grpc_network_status_shutdown_all_endpoints() {
+  gpr_mu_lock(&g_endpoint_mutex);
+  if (head == NULL) {
+    gpr_mu_unlock(&g_endpoint_mutex);
+    return;
+  }
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  for (endpoint_ll_node *curr = head; curr != NULL; curr = curr->next) {
+    curr->ep->vtable->shutdown(&exec_ctx, curr->ep);
+  }
+  gpr_mu_unlock(&g_endpoint_mutex);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
diff --git a/src/core/lib/iomgr/network_status_tracker.h b/src/core/lib/iomgr/network_status_tracker.h
new file mode 100644
index 0000000000..74a1aa8135
--- /dev/null
+++ b/src/core/lib/iomgr/network_status_tracker.h
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H
+#define GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H
+#include "src/core/lib/iomgr/endpoint.h"
+
+void grpc_network_status_register_endpoint(grpc_endpoint *ep);
+void grpc_network_status_unregister_endpoint(grpc_endpoint *ep);
+void grpc_network_status_shutdown_all_endpoints();
+#endif /* GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H */
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 1046b60bcc..2ab45e33ce 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -35,6 +35,7 @@
 
 #ifdef GPR_POSIX_SOCKET
 
+#include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
 
 #include <errno.h>
@@ -152,6 +153,7 @@ static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
 #endif
 
 static void tcp_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
   TCP_UNREF(exec_ctx, tcp, "destroy");
 }
@@ -474,6 +476,8 @@ grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd, size_t slice_size,
   tcp->write_closure.cb = tcp_handle_write;
   tcp->write_closure.cb_arg = tcp;
   gpr_slice_buffer_init(&tcp->last_read_buffer);
+  /* Tell network status tracker about new endpoint */
+  grpc_network_status_register_endpoint(&tcp->base);
 
   return &tcp->base;
 }
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index b2af8030aa..37ab59021e 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -37,6 +37,7 @@
 
 #include <limits.h>
 
+#include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
 #include <grpc/support/alloc.h>
@@ -378,6 +379,7 @@ static void win_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
 }
 
 static void win_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
   TCP_UNREF(tcp, "destroy");
 }
@@ -401,6 +403,9 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket, char *peer_string) {
   grpc_closure_init(&tcp->on_read, on_read, tcp);
   grpc_closure_init(&tcp->on_write, on_write, tcp);
   tcp->peer_string = gpr_strdup(peer_string);
+  /* Tell network status tracking code about the new endpoint */
+  grpc_network_status_register_endpoint(&tcp->base);
+
   return &tcp->base;
 }
 
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index ea4d17351c..b37e27c27e 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -105,6 +105,7 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/iomgr_posix.c',
   'src/core/lib/iomgr/iomgr_windows.c',
   'src/core/lib/iomgr/load_file.c',
+  'src/core/lib/iomgr/network_status_tracker.c',
   'src/core/lib/iomgr/polling_entity.c',
   'src/core/lib/iomgr/pollset_set_windows.c',
   'src/core/lib/iomgr/pollset_windows.c',