From 6ab062dfec990ec4915b2ca4514fbddff9bbd9a3 Mon Sep 17 00:00:00 2001
From: Xin Chen <xch@meta.com>
Date: Tue, 1 Aug 2023 12:19:17 -0700
Subject: [PATCH] Fix concurrent consumers issue with ReactMarker (#38710)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/38710

Fix a race condition when multiple consumers try to access ReactMarker and trigger calls to native module. Even though ReactMarker uses `ConcurrentLinkedQueue`, the loop itself could race and cause NPE.

Changelog:
[Android][Fixed] - Fix race condition with ReactMarker calls to its native module

Reviewed By: rshest

Differential Revision: D47933993

fbshipit-source-id: a56e5e4f3564922d534235991da5b6842248bf24
---
 .../src/main/java/com/facebook/react/bridge/ReactMarker.java  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactMarker.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactMarker.java
index ebfd755f8f7029..bf754a14952b6f 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactMarker.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactMarker.java
@@ -193,8 +193,8 @@ private static void notifyNativeMarker(ReactMarkerConstants name, @Nullable Long
       nativeLogMarker(name.name(), now);
 
       // Then send all cached native ReactMarkers
-      while (!sNativeReactMarkerQueue.isEmpty()) {
-        ReactMarkerRecord record = sNativeReactMarkerQueue.poll();
+      ReactMarkerRecord record;
+      while ((record = sNativeReactMarkerQueue.poll()) != null) {
         nativeLogMarker(record.getMarkerName(), record.getMarkerTime());
       }
     } else {