From 41b63719409f373a4b4f0cfc1de7d3ff95c74fd4 Mon Sep 17 00:00:00 2001
From: Fabrizio Cucci <fabriziocucci@meta.com>
Date: Tue, 12 Mar 2024 13:18:25 -0700
Subject: [PATCH] Synchronize access to LongLivedObjectCollection instances
 (#43450)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/43450

Changelog: [Internal]

This is just to make sure that all instances of `LongLivedObjectCollection` map can be safely accessed by multiple threads.

Reviewed By: RSNara

Differential Revision: D54801015

fbshipit-source-id: e0b15bfbeac9ce3a1051f83a59c5513a90ba2a4b
---
 .../ReactCommon/react/bridging/LongLivedObject.cpp             | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/react-native/ReactCommon/react/bridging/LongLivedObject.cpp b/packages/react-native/ReactCommon/react/bridging/LongLivedObject.cpp
index 64a93c1b7ec508..9c6d7c38d86fb2 100644
--- a/packages/react-native/ReactCommon/react/bridging/LongLivedObject.cpp
+++ b/packages/react-native/ReactCommon/react/bridging/LongLivedObject.cpp
@@ -16,6 +16,9 @@ LongLivedObjectCollection& LongLivedObjectCollection::get(
     jsi::Runtime& runtime) {
   static std::unordered_map<void*, std::shared_ptr<LongLivedObjectCollection>>
       instances;
+  static std::mutex instancesMutex;
+
+  std::scoped_lock lock(instancesMutex);
   void* key = static_cast<void*>(&runtime);
   auto entry = instances.find(key);
   if (entry == instances.end()) {