From 6c385c64334c1499a025b61c9b5dc2d2c093c040 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@meta.com>
Date: Thu, 27 Apr 2023 04:23:57 -0700
Subject: [PATCH] Fix race condition in SurfaceHandler (#37088)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/37088

changelog: [internal]

This is a race condition. parameters need to be copied out, otherwise they might be changed during read.

Reviewed By: luluwu2032

Differential Revision: D45272086

fbshipit-source-id: 9043762dfaaf61d08e187c0d83f743e991a94ed1
---
 .../react/renderer/scheduler/SurfaceHandler.cpp        | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp b/packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
index da00fd874bf..19f5e4476d9 100644
--- a/packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/scheduler/SurfaceHandler.cpp
@@ -112,6 +112,7 @@ void SurfaceHandler::stop() const noexcept {
 }
 
 void SurfaceHandler::setDisplayMode(DisplayMode displayMode) const noexcept {
+  auto parameters = Parameters{};
   {
     std::unique_lock lock(parametersMutex_);
     if (parameters_.displayMode == displayMode) {
@@ -119,6 +120,7 @@ void SurfaceHandler::setDisplayMode(DisplayMode displayMode) const noexcept {
     }
 
     parameters_.displayMode = displayMode;
+    parameters = parameters_;
   }
 
   {
@@ -129,10 +131,10 @@ void SurfaceHandler::setDisplayMode(DisplayMode displayMode) const noexcept {
     }
 
     link_.uiManager->setSurfaceProps(
-        parameters_.surfaceId,
-        parameters_.moduleName,
-        parameters_.props,
-        parameters_.displayMode);
+        parameters.surfaceId,
+        parameters.moduleName,
+        parameters.props,
+        parameters.displayMode);
 
     applyDisplayMode(displayMode);
   }