Unref global backup poller under its lock

1 files changed, 3 insertions, 1 deletions

diff --git a/src/core/ext/filters/client_channel/backup_poller.cc b/src/core/ext/filters/client_channel/backup_poller.cc
index ed437d255c..5b86e8631f 100644
--- a/src/core/ext/filters/client_channel/backup_poller.cc
+++ b/src/core/ext/filters/client_channel/backup_poller.cc
@@ -83,8 +83,8 @@ static void done_poller(grpc_exec_ctx* exec_ctx, void* arg, grpc_error* error) {
 }
 
 static void g_poller_unref(grpc_exec_ctx* exec_ctx) {
+  gpr_mu_lock(&g_poller_mu);
   if (gpr_unref(&g_poller->refs)) {
-    gpr_mu_lock(&g_poller_mu);
     backup_poller* p = g_poller;
     g_poller = nullptr;
     gpr_mu_unlock(&g_poller_mu);
@@ -95,6 +95,8 @@ static void g_poller_unref(grpc_exec_ctx* exec_ctx) {
                                             p, grpc_schedule_on_exec_ctx));
     gpr_mu_unlock(p->pollset_mu);
     grpc_timer_cancel(exec_ctx, &p->polling_timer);
+  } else {
+    gpr_mu_unlock(&g_poller_mu);
   }
 }