From d10b2a677dc5a34595cf8338c99f2d772c2047a7 Mon Sep 17 00:00:00 2001
From: "Denny C. Dai" <dennycd@google.com>
Date: Tue, 24 Aug 2021 14:13:52 -0700
Subject: [PATCH] [gRPC-ObjC] Fix potential over releasing crash for grp
 channel (#27061)

---
 src/objective-c/GRPCClient/private/GRPCCore/GRPCChannel.m | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/objective-c/GRPCClient/private/GRPCCore/GRPCChannel.m b/src/objective-c/GRPCClient/private/GRPCCore/GRPCChannel.m
index 5ad1cb462d4..5727f01c96a 100644
--- a/src/objective-c/GRPCClient/private/GRPCCore/GRPCChannel.m
+++ b/src/objective-c/GRPCClient/private/GRPCCore/GRPCChannel.m
@@ -291,8 +291,11 @@
 }
 
 - (void)dealloc {
-  if (_unmanagedChannel) {
-    grpc_channel_destroy(_unmanagedChannel);
+  @synchronized(self) {
+    if (_unmanagedChannel) {
+      grpc_channel_destroy(_unmanagedChannel);
+      _unmanagedChannel = NULL;
+    }
   }
 }