From 20f1f62d9b5a2eee0c845da63db7670f29f8809e Mon Sep 17 00:00:00 2001
From: Fabrizio Cucci <fabriziocucci@meta.com>
Date: Tue, 12 Mar 2024 10:44:37 -0700
Subject: [PATCH] Synchronize access to LongLivedObjectCollection instances

Summary:
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
---
 .../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 64a93c1b7ec5..9c6d7c38d86f 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()) {