3.15 socketio disconnect socket will crash！ High probability,

[huangapple]

cocos's tests/cpp-tests will crash. 3.15 socketio disconnect socket will crash！ High probability,

[continuemycoding]

@minggo @dumganhar 3.15版本的WebSocket关闭时有死锁问题，出现概率非常非常高。我是这样修复的，有更好的方案？

[minggo]

I have asked @dumganhar to take a look.

[dumganhar]

@gdboy WebSocket::close is a synchronous method. Therefore, it has to wait the WebSocket thread to receive closed event. So your patch changes the logic of WebSocket::close. Currently, we provide WebSocket::closeAsync interface for closing websocket asynchronously.

Could you tell us how did you reproduce the dead lock issue ? Is there an easy way to reproduce it?

[dumganhar]

BTW, I think dead lock should not cause crash issue. So @gdboy 's issue isn't relative to this one.

[continuemycoding]

@dumganhar 在截图中的这个测试样例，只要open close就会出现死锁，我测试来看，这个bug三次至少出现一次。死锁时界面卡死不动，跟崩溃是一样的。我那样改也是有用锁进行同步等待，我看你们原先的代码是有逻辑问题。

[continuemycoding]

@dumganhar 英文只有阅读的能力，中文回复勿怪。

[dumganhar]

@gdboy , but your _closeCondition.wait() is in the onConnectionClosed which is invoked in sub-thread rather than cocos's thread. I will make no sense. And the WebSocket::close will return without waiting websocket instance to be closed.

[continuemycoding]

@dumganhar onConnectionClosed 顾名思义应该是在close完成的时候回调的？onConnectionClosed 应该是等待 WebSocket::close 才对吧？而且那样改之后确实解决了死锁问题，之前死锁大概率发生，需要等个十几秒至几十秒才能满足等待锁的条件。

[dumganhar]

@gdboy websocket close event will be triggered by websocket server so it probably should wait some time for receive that event. You could use WebSocket::closeAsync for close the websocket asynchronously. Yep, yep, SocketIO currently has some issues that it's hard to be fixed. We need to do some refactor on that. and SocketIO::disconnect should invoke WebSocket::closeAsync instead for not blocking the user's thread.

[continuemycoding]

@dumganhar 如果不那样解决，那这个死锁问题怎么解决好？没试过WebSocket::closeAsync，但是WebSocket::close确实存在大概率死锁问题。

[continuemycoding]

@dumganhar disconnect里面调用的不是WebSocket::closeAsync而是WebSocket::close，原先代码死锁几乎必现。