升级React Native 0.54.2后iOS应用闲置冻结，报RCTSRWebSocketErrorDomain错误求助

Hey, I’ve dealt with this exact frustrating freeze problem after upgrading to React Native 0.54.2—my iOS app would lock up solid after sitting idle for a few minutes, and the crash logs pointed straight to RCTSRWebSocket.m too. Here’s what worked for me and what I learned from the dev community:

Common Root Cause #

This is a known deadlock bug in the RCTSRWebSocket implementation included in RN 0.54.2. The issue happens when the WebSocket’s idle cleanup/heartbeat logic gets stuck on a synchronized lock, blocking the main thread entirely.

Quick Fixes to Try #

1. Patch the RCTSRWebSocket.m File #

You can manually fix the deadlock by adjusting the lock handling in the _closeWithCode:reason: method:

• Open your project’s RCTWebSocket.xcodeproj → RCTSRWebSocket.m
• Find the method - (void)_closeWithCode:(NSInteger)code reason:(NSString *)reason
• Replace the @synchronized(self) block with a serial dispatch queue to avoid lock contention. For example:

  static dispatch_queue_t rctSRWebSocketCloseQueue;
  static dispatch_once_t onceToken;
  dispatch_once(&onceToken, ^{
      rctSRWebSocketCloseQueue = dispatch_queue_create("com.facebook.react.WebSocketCloseQueue", DISPATCH_QUEUE_SERIAL);
  });
  
  dispatch_sync(rctSRWebSocketCloseQueue, ^{
      // Move all the code from the original @synchronized(self) block here
      if (_closeCode == RCTSRWebSocketCloseCodeNotInitialized) {
          _closeCode = code;
          _closeReason = [reason copy];
          [self _performClose];
      }
  });
  

• Clean your Xcode build (Cmd+Shift+K) and rebuild the app.

2. Upgrade to a Newer React Native Version #

The RN team fixed this WebSocket deadlock in versions 0.55.0 and later. If you can afford to upgrade, that’s the most sustainable solution. Just run:

react-native upgrade 0.55.0

(Note: You’ll need to handle any breaking changes between 0.54.2 and 0.55.0, but the fix is worth it.)

3. Disable Unnecessary WebSocket Connections #

If you’re using third-party libraries that use WebSockets (like chat SDKs, push services, or analytics tools), temporarily disable them to see if the freeze stops. Sometimes these libraries can clash with RN’s built-in WebSocket implementation in this version.

Troubleshooting Steps to Confirm the Issue #

• Use Xcode’s Debug Navigator when the app freezes: Check the main thread’s call stack—you’ll likely see it stuck on objc_sync_enter within RCTSRWebSocket.
• Run Instruments to check for WebSocket instance leaks: If old WebSocket connections aren’t being properly released, they can pile up and trigger the deadlock faster.

内容的提问来源于stack exchange，提问作者Friendly-Robot