PeerConnectionClient thread safety.

Signal/src/call/CallService.swift

@@ -449,9 +449,8 @@ private class SignalCallData: NSObject {
             self.handleFailedCall(failedCall: call, error: .obsoleteCall(description:"obsolete call in \(#function)"))
             return
         }
-
         guard callData.call == call else {
-            self.handleFailedCall(failedCall: call, error: .obsoleteCall(description:"obsolete call in \(#function)"))
+            Logger.warn("\(self.logTag) ignoring \(#function) for call other than current call")
             return
         }
 
@@ -746,6 +745,7 @@ private class SignalCallData: NSObject {
      * Remote client (could be caller or callee) sent us a connectivity update
      */
     public func handleRemoteAddedIceCandidate(thread: TSContactThread, callId: UInt64, sdp: String, lineIndex: Int32, mid: String) {
+        SwiftAssertIsOnMainThread(#function)
         Logger.verbose("\(logTag) \(#function) callId: \(callId)")
 
         guard let callData = self.callData else {
@@ -1001,7 +1001,7 @@ private class SignalCallData: NSObject {
         Logger.info("\(self.logTag) in \(#function)")
         SwiftAssertIsOnMainThread(#function)
 
-        guard let peerConnectionClient = self.peerConnectionClient else {
+        guard let peerConnectionClient = callData.peerConnectionClient else {
             OWSProdError(OWSAnalyticsEvents.callServicePeerConnectionMissing(), file: #file, function: #function, line: #line)
             handleFailedCall(failedCall: call, error: CallError.assertionError(description: "\(self.logTag) peerConnectionClient unexpectedly nil in \(#function)"))
             return

Signal/src/call/PeerConnectionClient.swift

@@ -412,7 +412,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
             }
 
             peerConnection.offer(for: strongSelf.defaultOfferConstraints, completionHandler: { (sdp: RTCSessionDescription?, error: Error?) in
-                PeerConnectionClient.signalingQueue.async {
+                PeerConnectionClient.signalingQueue.async { [weak self] in
                     completion(sdp, error)
                 }
             })
@@ -549,7 +549,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
             Logger.debug("\(strongSelf.logTag) negotiating answer session.")
 
             peerConnection.answer(for: constraints, completionHandler: { (sdp: RTCSessionDescription?, error: Error?) in
-                PeerConnectionClient.signalingQueue.async {
+                PeerConnectionClient.signalingQueue.async { [weak self] in
                     completion(sdp, error)
                 }
             })
@@ -608,6 +608,10 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
         localVideoTrack?.isEnabled = false
         remoteVideoTrack?.isEnabled = false
 
+        if let dataChannel = self.dataChannel {
+            dataChannel.delegate = nil
+        }
+
         dataChannel = nil
         audioSender = nil
         audioTrack = nil
@@ -701,7 +705,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
                 return
             }
 
-            DispatchQueue.main.async {
+            DispatchQueue.main.async { [weak self] in
                 completion(dataChannelMessage)
             }
         }
@@ -751,7 +755,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
 
             strongSelf.remoteVideoTrack = remoteVideoTrack
 
-            DispatchQueue.main.async {
+            DispatchQueue.main.async { [weak self] in
                 completion(remoteVideoTrack)
             }
         }
@@ -842,7 +846,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
                 return
             }
             Logger.info("\(strongSelf.logTag) adding local ICE candidate:\(candidate.sdp)")
-            DispatchQueue.main.async {
+            DispatchQueue.main.async { [weak self] in
                 completion(candidate)
             }
         }
@@ -883,7 +887,7 @@ class PeerConnectionClient: NSObject, RTCPeerConnectionDelegate, RTCDataChannelD
 
             let pendingMessages = strongSelf.pendingDataChannelMessages
             strongSelf.pendingDataChannelMessages = []
-            DispatchQueue.main.async {
+            DispatchQueue.main.async { [weak self] in
                 completion(pendingMessages)
             }
         }