Merge pull request #12808 from sreecha/cq_stats

Counter for number of trylocks (successes/failures) and transient pop-failures in cq

1 files changed, 14 insertions, 1 deletions

diff --git a/src/core/lib/surface/completion_queue.cc b/src/core/lib/surface/completion_queue.cc
index 36b4b835f8..21664f03c8 100644
--- a/src/core/lib/surface/completion_queue.cc
+++ b/src/core/lib/surface/completion_queue.cc
@@ -362,11 +362,24 @@ static bool cq_event_queue_push(grpc_cq_event_queue *q, grpc_cq_completion *c) {
 
 static grpc_cq_completion *cq_event_queue_pop(grpc_cq_event_queue *q) {
   grpc_cq_completion *c = NULL;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
   if (gpr_spinlock_trylock(&q->queue_lock)) {
-    c = (grpc_cq_completion *)gpr_mpscq_pop(&q->queue);
+    GRPC_STATS_INC_CQ_EV_QUEUE_TRYLOCK_SUCCESSES(&exec_ctx);
+
+    bool is_empty = false;
+    c = (grpc_cq_completion *)gpr_mpscq_pop_and_check_end(&q->queue, &is_empty);
     gpr_spinlock_unlock(&q->queue_lock);
+
+    if (c == NULL && !is_empty) {
+      GRPC_STATS_INC_CQ_EV_QUEUE_TRANSIENT_POP_FAILURES(&exec_ctx);
+    }
+  } else {
+    GRPC_STATS_INC_CQ_EV_QUEUE_TRYLOCK_FAILURES(&exec_ctx);
   }
 
+  grpc_exec_ctx_finish(&exec_ctx);
+
   if (c) {
     gpr_atm_no_barrier_fetch_add(&q->num_queue_items, -1);
   }