Consistent acq/rel semantics for pending_events atomic

src/core/lib/surface/completion_queue.c

@@ -444,7 +444,7 @@ grpc_completion_queue *grpc_completion_queue_create_internal(
 static void cq_init_next(void *ptr) {
   cq_next_data *cqd = (cq_next_data *)ptr;
   /* Initial count is dropped by grpc_completion_queue_shutdown */
-  gpr_atm_no_barrier_store(&cqd->pending_events, 1);
+  gpr_atm_rel_store(&cqd->pending_events, 1);
   cqd->shutdown_called = false;
   gpr_atm_no_barrier_store(&cqd->things_queued_ever, 0);
   cq_event_queue_init(&cqd->queue);
@@ -459,7 +459,7 @@ static void cq_destroy_next(void *ptr) {
 static void cq_init_pluck(void *ptr) {
   cq_pluck_data *cqd = (cq_pluck_data *)ptr;
   /* Initial count is dropped by grpc_completion_queue_shutdown */
-  gpr_atm_no_barrier_store(&cqd->pending_events, 1);
+  gpr_atm_rel_store(&cqd->pending_events, 1);
   cqd->completed_tail = &cqd->completed_head;
   cqd->completed_head.next = (uintptr_t)cqd->completed_tail;
   gpr_atm_no_barrier_store(&cqd->shutdown, 0);
@@ -560,13 +560,13 @@ static void cq_check_tag(grpc_completion_queue *cq, void *tag, bool lock_cq) {}
  * true if the increment was successful; false if the counter is zero */
 static bool atm_inc_if_nonzero(gpr_atm *counter) {
   while (true) {
-    gpr_atm count = gpr_atm_no_barrier_load(counter);
+    gpr_atm count = gpr_atm_acq_load(counter);
     /* If zero, we are done. If not, we must to a CAS (instead of an atomic
      * increment) to maintain the contract: do not increment the counter if it
      * is zero. */
     if (count == 0) {
       return false;
-    } else if (gpr_atm_no_barrier_cas(counter, count, count + 1)) {
+    } else if (gpr_atm_full_cas(counter, count, count + 1)) {
       break;
     }
   }
@@ -638,8 +638,7 @@ static void cq_end_op_for_next(grpc_exec_ctx *exec_ctx,
   /* Add the completion to the queue */
   bool is_first = cq_event_queue_push(&cqd->queue, storage);
   gpr_atm_no_barrier_fetch_add(&cqd->things_queued_ever, 1);
-  bool will_definitely_shutdown =
-      gpr_atm_no_barrier_load(&cqd->pending_events) == 1;
+  bool will_definitely_shutdown = gpr_atm_acq_load(&cqd->pending_events) == 1;
 
   if (!will_definitely_shutdown) {
     /* Only kick if this is the first item queued */
@@ -883,7 +882,7 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
       }
     }
 
-    if (gpr_atm_no_barrier_load(&cqd->pending_events) == 0) {
+    if (gpr_atm_acq_load(&cqd->pending_events) == 0) {
       /* Before returning, check if the queue has any items left over (since
          gpr_mpscq_pop() can sometimes return NULL even if the queue is not
          empty. If so, keep retrying but do not return GRPC_QUEUE_SHUTDOWN */
@@ -929,7 +928,7 @@ static grpc_event cq_next(grpc_completion_queue *cq, gpr_timespec deadline,
   }
 
   if (cq_event_queue_num_items(&cqd->queue) > 0 &&
-      gpr_atm_no_barrier_load(&cqd->pending_events) > 0) {
+      gpr_atm_acq_load(&cqd->pending_events) > 0) {
     gpr_mu_lock(cq->mu);
     cq->poller_vtable->kick(POLLSET_FROM_CQ(cq), NULL);
     gpr_mu_unlock(cq->mu);
@@ -956,7 +955,7 @@ static void cq_finish_shutdown_next(grpc_exec_ctx *exec_ctx,
   cq_next_data *cqd = DATA_FROM_CQ(cq);
 
   GPR_ASSERT(cqd->shutdown_called);
-  GPR_ASSERT(gpr_atm_no_barrier_load(&cqd->pending_events) == 0);
+  GPR_ASSERT(gpr_atm_acq_load(&cqd->pending_events) == 0);
 
   cq->poller_vtable->shutdown(exec_ctx, POLLSET_FROM_CQ(cq),
                               &cq->pollset_shutdown_done);