From c7fcebe75011567b3ac1a100cbacb82105c902b6 Mon Sep 17 00:00:00 2001
From: Alexander Polcyn <apolcyn@google.com>
Date: Sat, 15 Apr 2017 16:37:44 -0700
Subject: [PATCH] fix bug in which gc of channel sleeps on cv before bg thread
signaling has started
---
src/ruby/ext/grpc/rb_channel.c | 45 +++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index 6d12ff9ebd..aead45c082 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -92,7 +92,9 @@ static void grpc_rb_channel_safe_destroy(grpc_rb_channel *wrapper);
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) {
@@ -479,6 +481,14 @@ 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_signal(&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);
@@ -510,9 +520,24 @@ static VALUE run_poll_channels_loop(VALUE arg) {
gpr_log(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);
+
return Qnil;
}
+static void *grpc_rb_wait_until_channel_polling_thread_started(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;
+}
+
+
/* Temporary fix for
* https://github.com/GoogleCloudPlatform/google-cloud-ruby/issues/899.
* Transports in idle channels can get destroyed. Normally c-core re-connects,
@@ -524,12 +549,30 @@ static VALUE run_poll_channels_loop(VALUE arg) {
* TODO(apolcyn) remove this when core handles new RPCs on dead connections.
*/
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);
+ gpr_cv_init(&global_connection_polling_cv);
+
channel_polling_cq = grpc_completion_queue_create(NULL);
- rb_thread_create(run_poll_channels_loop, 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_mu_unlock(&global_connection_polling_mu);
+ return;
+ }
+
+ // Drop the gil before sleeping on a gpr_cv so that the background thread
+ // signaling it can acquire the gil and then start, if it hasn't already.
+ rb_thread_call_without_gvl(grpc_rb_wait_until_channel_polling_thread_started, NULL,
+ grpc_rb_event_unblocking_func, NULL);
}
static void Init_grpc_propagate_masks() {
--
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