[iOS][FIXED] Data race related to read/write on ReactMarker::logTaggedMarkerImpl

packages/react-native/React/CxxBridge/RCTCxxBridge.mm

@@ -162,11 +162,13 @@ static void mapReactMarkerToPerformanceLogger(
 
 static void registerPerformanceLoggerHooks(RCTPerformanceLogger *performanceLogger)
 {
+  std::unique_lock lock(ReactMarker::logTaggedMarkerImplMutex);
   __weak RCTPerformanceLogger *weakPerformanceLogger = performanceLogger;
-  ReactMarker::logTaggedMarkerImpl = [weakPerformanceLogger](
+  ReactMarker::LogTaggedMarker newMarker = [weakPerformanceLogger](
                                          const ReactMarker::ReactMarkerId markerId, const char *tag) {
     mapReactMarkerToPerformanceLogger(markerId, weakPerformanceLogger, tag);
   };
+  ReactMarker::logTaggedMarkerImpl = newMarker;
 }
 
 @interface RCTCxxBridge () <RCTModuleDataCallInvokerProvider>

packages/react-native/ReactAndroid/src/main/jni/react/jni/JReactMarker.cpp

@@ -16,6 +16,7 @@ namespace facebook::react {
 void JReactMarker::setLogPerfMarkerIfNeeded() {
   static std::once_flag flag{};
   std::call_once(flag, []() {
+    std::unique_lock lock(ReactMarker::logTaggedMarkerImplMutex);
     ReactMarker::logTaggedMarkerImpl = JReactMarker::logPerfMarker;
     ReactMarker::logTaggedMarkerBridgelessImpl =
         JReactMarker::logPerfMarkerBridgeless;

packages/react-native/ReactCommon/cxxreact/ReactMarker.cpp

@@ -16,8 +16,9 @@ namespace ReactMarker {
 #pragma clang diagnostic ignored "-Wglobal-constructors"
 #endif
 
-LogTaggedMarker logTaggedMarkerImpl = nullptr;
 LogTaggedMarker logTaggedMarkerBridgelessImpl = nullptr;
+LogTaggedMarker logTaggedMarkerImpl = nullptr;
+std::shared_mutex logTaggedMarkerImplMutex;
 
 #if __clang__
 #pragma clang diagnostic pop
@@ -28,7 +29,14 @@ void logMarker(const ReactMarkerId markerId) {
 }
 
 void logTaggedMarker(const ReactMarkerId markerId, const char* tag) {
-  logTaggedMarkerImpl(markerId, tag);
+  LogTaggedMarker marker = nullptr;
+  {
+    std::shared_lock lock(logTaggedMarkerImplMutex);
+    marker = logTaggedMarkerImpl;
+  }
+  if (marker) {
+    marker(markerId, tag);
+  }
 }
 
 void logMarkerBridgeless(const ReactMarkerId markerId) {

packages/react-native/ReactCommon/cxxreact/ReactMarker.h

@@ -8,6 +8,7 @@
 #pragma once
 
 #include <cmath>
+#include <shared_mutex>
 
 #ifdef __APPLE__
 #include <functional>
@@ -51,7 +52,9 @@ typedef void (*LogTaggedMarkerBridgeless)(const ReactMarkerId, const char* tag);
 #define RN_EXPORT __attribute__((visibility("default")))
 #endif
 
-extern RN_EXPORT LogTaggedMarker logTaggedMarkerImpl; // Bridge only
+extern RN_EXPORT std::shared_mutex logTaggedMarkerImplMutex;
+/// - important: To ensure this gets read and written to in a thread safe manner, make use of `logTaggedMarkerImplMutex`.
+extern RN_EXPORT LogTaggedMarker logTaggedMarkerImpl;
 extern RN_EXPORT LogTaggedMarker logTaggedMarkerBridgelessImpl;
 
 extern RN_EXPORT void logMarker(const ReactMarkerId markerId); // Bridge only

packages/react-native/ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp

@@ -139,8 +139,11 @@ void JSIExecutor::initializeRuntime() {
   if (runtimeInstaller_) {
     runtimeInstaller_(*runtime_);
   }
-
-  bool hasLogger(ReactMarker::logTaggedMarkerImpl);
+  bool hasLogger = false;
+  {
+    std::shared_lock lock(ReactMarker::logTaggedMarkerImplMutex);
+    hasLogger = ReactMarker::logTaggedMarkerImpl != nullptr;
+  }
   if (hasLogger) {
     ReactMarker::logMarker(ReactMarker::CREATE_REACT_CONTEXT_STOP);
   }
@@ -150,8 +153,11 @@ void JSIExecutor::loadBundle(
     std::unique_ptr<const JSBigString> script,
     std::string sourceURL) {
   SystraceSection s("JSIExecutor::loadBundle");
-
-  bool hasLogger(ReactMarker::logTaggedMarkerImpl);
+  bool hasLogger = false;
+  {
+    std::shared_lock lock(ReactMarker::logTaggedMarkerImplMutex);
+    hasLogger = ReactMarker::logTaggedMarkerImpl != nullptr;
+  }
   std::string scriptName = simpleBasename(sourceURL);
   if (hasLogger) {
     ReactMarker::logTaggedMarker(

packages/react-native/ReactCommon/jsiexecutor/jsireact/JSINativeModules.cpp

@@ -67,7 +67,11 @@ void JSINativeModules::reset() {
 std::optional<Object> JSINativeModules::createModule(
     Runtime& rt,
     const std::string& name) {
-  bool hasLogger(ReactMarker::logTaggedMarkerImpl);
+  bool hasLogger = false;
+  {
+    std::shared_lock lock(ReactMarker::logTaggedMarkerImplMutex);
+    hasLogger = ReactMarker::logTaggedMarkerImpl != nullptr;
+  }
   if (hasLogger) {
     ReactMarker::logTaggedMarker(
         ReactMarker::NATIVE_MODULE_SETUP_START, name.c_str());