Merge remote-tracking branch 'upstream/v1.3.x' into upmerge_v1.3.x

1 files changed, 67 insertions, 8 deletions

diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index ecfffd1839..a802183726 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -89,10 +89,14 @@ typedef struct grpc_rb_channel {
 static void grpc_rb_channel_try_register_connection_polling(
     grpc_rb_channel *wrapper);
 static void grpc_rb_channel_safe_destroy(grpc_rb_channel *wrapper);
+static void *wait_until_channel_polling_thread_started_no_gil(void *);
+static void wait_until_channel_polling_thread_started_unblocking_func(void *);
 
 static grpc_completion_queue *channel_polling_cq;
 static gpr_mu global_connection_polling_mu;
+static gpr_cv global_connection_polling_cv;
 static int abort_channel_polling = 0;
+static int channel_polling_thread_started = 0;
 
 /* Destroys Channel instances. */
 static void grpc_rb_channel_free(void *p) {
@@ -166,6 +170,11 @@ static VALUE grpc_rb_channel_init(int argc, VALUE *argv, VALUE self) {
   grpc_channel_args args;
   MEMZERO(&args, grpc_channel_args, 1);
 
+  grpc_ruby_once_init();
+  rb_thread_call_without_gvl(
+      wait_until_channel_polling_thread_started_no_gil, NULL,
+      wait_until_channel_polling_thread_started_unblocking_func, NULL);
+
   /* "3" == 3 mandatory args */
   rb_scan_args(argc, argv, "3", &target, &channel_args, &credentials);
 
@@ -440,6 +449,7 @@ static void grpc_rb_channel_try_register_connection_polling(
   }
   gpr_mu_lock(&global_connection_polling_mu);
 
+  GPR_ASSERT(channel_polling_thread_started || abort_channel_polling);
   conn_state = grpc_channel_check_connectivity_state(wrapper->wrapped, 0);
   if (conn_state != wrapper->current_connectivity_state) {
     wrapper->current_connectivity_state = conn_state;
@@ -473,7 +483,7 @@ static void grpc_rb_channel_safe_destroy(grpc_rb_channel *wrapper) {
 }
 
 // Note this loop breaks out with a single call of
-// "grpc_rb_event_unblocking_func".
+// "run_poll_channels_loop_no_gil".
 // This assumes that a ruby call the unblocking func
 // indicates process shutdown.
 // In the worst case, this stops polling channel connectivity
@@ -481,6 +491,14 @@ static void grpc_rb_channel_safe_destroy(grpc_rb_channel *wrapper) {
 static void *run_poll_channels_loop_no_gil(void *arg) {
   grpc_event event;
   (void)arg;
+  gpr_log(GPR_DEBUG, "GRPC_RUBY: run_poll_channels_loop_no_gil - begin");
+
+  gpr_mu_lock(&global_connection_polling_mu);
+  GPR_ASSERT(!channel_polling_thread_started);
+  channel_polling_thread_started = 1;
+  gpr_cv_broadcast(&global_connection_polling_cv);
+  gpr_mu_unlock(&global_connection_polling_mu);
+
   for (;;) {
     event = grpc_completion_queue_next(
         channel_polling_cq, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
@@ -500,7 +518,7 @@ static void *run_poll_channels_loop_no_gil(void *arg) {
 }
 
 // Notify the channel polling loop to cleanup and shutdown.
-static void grpc_rb_event_unblocking_func(void *arg) {
+static void run_poll_channels_loop_unblocking_func(void *arg) {
   (void)arg;
   gpr_mu_lock(&global_connection_polling_mu);
   gpr_log(GPR_DEBUG,
@@ -518,10 +536,37 @@ static VALUE run_poll_channels_loop(VALUE arg) {
       GPR_DEBUG,
       "GRPC_RUBY: run_poll_channels_loop - create connection polling thread");
   rb_thread_call_without_gvl(run_poll_channels_loop_no_gil, NULL,
-                             grpc_rb_event_unblocking_func, NULL);
+                             run_poll_channels_loop_unblocking_func, NULL);
+
   return Qnil;
 }
 
+static void *wait_until_channel_polling_thread_started_no_gil(void *arg) {
+  (void)arg;
+  gpr_log(GPR_DEBUG, "GRPC_RUBY: wait for channel polling thread to start");
+  gpr_mu_lock(&global_connection_polling_mu);
+  while (!channel_polling_thread_started && !abort_channel_polling) {
+    gpr_cv_wait(&global_connection_polling_cv, &global_connection_polling_mu,
+                gpr_inf_future(GPR_CLOCK_REALTIME));
+  }
+  gpr_mu_unlock(&global_connection_polling_mu);
+
+  return NULL;
+}
+
+static void wait_until_channel_polling_thread_started_unblocking_func(
+    void *arg) {
+  (void)arg;
+  gpr_mu_lock(&global_connection_polling_mu);
+  gpr_log(GPR_DEBUG,
+          "GRPC_RUBY: "
+          "wait_until_channel_polling_thread_started_unblocking_func - begin "
+          "aborting connection polling");
+  abort_channel_polling = 1;
+  gpr_cv_broadcast(&global_connection_polling_cv);
+  gpr_mu_unlock(&global_connection_polling_mu);
+}
+
 /* Temporary fix for
  * https://github.com/GoogleCloudPlatform/google-cloud-ruby/issues/899.
  * Transports in idle channels can get destroyed. Normally c-core re-connects,
@@ -532,11 +577,26 @@ static VALUE run_poll_channels_loop(VALUE arg) {
  * calls - so that c-core can reconnect if needed, when there aren't any RPC's.
  * TODO(apolcyn) remove this when core handles new RPCs on dead connections.
  */
-static void start_poll_channels_loop() {
-  channel_polling_cq = grpc_completion_queue_create_for_next(NULL);
+void grpc_rb_channel_polling_thread_start() {
+  VALUE background_thread = Qnil;
+
+  GPR_ASSERT(!abort_channel_polling);
+  GPR_ASSERT(!channel_polling_thread_started);
+  GPR_ASSERT(channel_polling_cq == NULL);
+
   gpr_mu_init(&global_connection_polling_mu);
-  abort_channel_polling = 0;
-  rb_thread_create(run_poll_channels_loop, NULL);
+  gpr_cv_init(&global_connection_polling_cv);
+
+  channel_polling_cq = grpc_completion_queue_create_for_next(NULL);
+  background_thread = rb_thread_create(run_poll_channels_loop, NULL);
+
+  if (!RTEST(background_thread)) {
+    gpr_log(GPR_DEBUG, "GRPC_RUBY: failed to spawn channel polling thread");
+    gpr_mu_lock(&global_connection_polling_mu);
+    abort_channel_polling = 1;
+    gpr_cv_broadcast(&global_connection_polling_cv);
+    gpr_mu_unlock(&global_connection_polling_mu);
+  }
 }
 
 static void Init_grpc_propagate_masks() {
@@ -608,7 +668,6 @@ void Init_grpc_channel() {
   id_insecure_channel = rb_intern("this_channel_is_insecure");
   Init_grpc_propagate_masks();
   Init_grpc_connectivity_states();
-  start_poll_channels_loop();
 }
 
 /* Gets the wrapped channel from the ruby wrapper */