handleAck crash

[patmalt]

Crashed Thread 3 :
--
0 | SocketIO | 0x103298e74 | handleAck () (<compiler-generated>:0)
1 | SocketIO | 0x103298e74 | handleAck () (<compiler-generated>:0)
2 | SocketIO | 0x10329969c | handlePacket () (SocketIOClient.swift:387)
3 | SocketIO | 0x1032abb4c | _parseEngineMessage () (SocketManager.swift:415)
4 | SocketIO | 0x1032aad14 | SocketIO + 224532
5 | SocketIO | 0x10327c2f8 | (unknown) (<compiler-generated>:0)

Has anyone else seen this crash before?

Should the SocketAckManager handle everything (including insert) on the socket client's handleQueue?

[patmalt]

This comment from SocketIOClient.swift makes me thing so...

**NOTE**: The client is not thread/queue safe, all interaction with the socket should be done on the `manager.handleQueue`

[kasyrm]

I'm having a similar problem. The crash accours very rarely and randomly. I was not able to reproduce it on purpose.

Crashed: com.XYZ.socket
0  SocketIO                    	0x10194c9d4 specialized Set._Variant.insert(_:) (<compiler-generated>)
1  SocketIO                     	 0x10194b918 OnAckCallback.timingOut(after:callback:) + 66 (SocketAckManager.swift:66)
2  XYZ                       	0x100171ee8 specialized SocketModule.performMethod<A>(_:request:params:dispatchQueue:handler:) + 105 (<compiler-generated>:105)
3  XYZ                      	0x1002558d8 specialized static Api.fetchUserProfile(reloadHandler:) + 89 (AppState.swift:89)
4  XYZ                       	0x10032be00 XYZSocketManager.emitClient() (AppState.swift)
5  XYZ                       	0x10032a220 closure #1 in XYZSocketManager.registerServer() + 207 (XYZSocketManager.swift:207)
6  SocketIO                      0x10196cf44 specialized SocketIOClient.handleEvent(_:data:isInternalMessage:withAck:) (SocketIOClient.swift)
7  SocketIO                       0x101969d34 SocketIOClient.handlePacket(_:) (<compiler-generated>)
8  SocketIO                       0x10197bf7c specialized SocketManager._parseEngineMessage(_:) + 416 (SocketManager.swift:416)
9  SocketIO                       0x10197b144 partial apply for closure #1 in SocketManager.engineDidClose(reason:) + 4389892420
10 SocketIO                       0x10194bda4 thunk for @escaping @callee_guaranteed () -> () (<compiler-generated>)
11 libdispatch.dylib              0x18c550a38 _dispatch_call_block_and_release + 24
12 libdispatch.dylib              0x18c5517d4 _dispatch_client_callout + 16
13 libdispatch.dylib              0x18c52cdec _dispatch_lane_serial_drain$VARIANT$armv81 + 548
14 libdispatch.dylib              0x18c52d92c _dispatch_lane_invoke$VARIANT$armv81 + 408
15 libdispatch.dylib              0x18c535e08 _dispatch_workloop_worker_thread + 584
16 libsystem_pthread.dylib        0x18c731114 _pthread_wqthread + 304
17 libsystem_pthread.dylib        0x18c733cd4 start_wqthread + 4

[patmalt]

@kasyrm Please see my comment above. We were able to solve this crash by dispatching any interaction with an instance of SocketIOClient onto the manager.handleQueue.

[kasyrm]

It seems it works, thanks!

[aidevpk]

@patmalt Can you give me an example on how to actually use it. Do you mean it like this:

self.manager?.handleQueue.async {
            if self.socket?.status != .connected {
                self.connectSocket(handler: {
                    self.emitWithACK(withTimeoutAfter: 15, event: event, params: nil, array: array)
                })
            } else {
                self.emitWithACK(withTimeoutAfter: 15, event: event, params: nil, array : array)
            }
        }

Do I need to to perform this only for my emit calls? @kasyrm Can you help ?

[patmalt]

Yes, that's correct. We put EVERY interaction with the socket on the manager's queue. Did it help?

[aidevpk]

func emit(with event: String , _ params : JSONDictionary?, timeoutAfter: Double = 15.0, ackHandler: (([Any]) -> Void)? = nil){
        self.manager?.handleQueue.async {
            self.connectSocket(handler: {
                self.emitWithACK(withTimeoutAfter: timeoutAfter, event: event, params: params, array: nil) {
                    ack in
                    ackHandler?(ack)
                }
            })
        }
    }

@patmalt Please confirm this method now. So I have a singleton class with this method. I am calling this emit method from different threads. is it okay ? and also let me know if I can do all my emits on Main Thread or will it impact the performance significantly ?

[kasyrm]

To make it work I did all the emits on manager.handleQueue and then I would dispatch a response to whatever queue I needed.