delay discovered ice candidates until JingleRtpConnection is ready to receive

otherwise setLocalDescription and the arrival of first candidates might race
the rtpContentDescription being set

src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java

@@ -34,6 +34,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 
@@ -567,6 +568,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         final SessionDescription sessionDescription = SessionDescription.parse(webRTCSessionDescription.description);
         final RtpContentMap respondingRtpContentMap = RtpContentMap.of(sessionDescription);
         this.responderRtpContentMap = respondingRtpContentMap;
+        webRTCWrapper.setIsReadyToReceiveIceCandidates(true);
         final ListenableFuture<RtpContentMap> outgoingContentMapFuture = prepareOutgoingContentMap(respondingRtpContentMap);
         Futures.addCallback(outgoingContentMapFuture,
                 new FutureCallback<RtpContentMap>() {
@@ -872,6 +874,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         final SessionDescription sessionDescription = SessionDescription.parse(webRTCSessionDescription.description);
         final RtpContentMap rtpContentMap = RtpContentMap.of(sessionDescription);
         this.initiatorRtpContentMap = rtpContentMap;
+        this.webRTCWrapper.setIsReadyToReceiveIceCandidates(true);
         final ListenableFuture<RtpContentMap> outgoingContentMapFuture = encryptSessionInitiate(rtpContentMap);
         Futures.addCallback(outgoingContentMapFuture, new FutureCallback<RtpContentMap>() {
             @Override
@@ -1339,7 +1342,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
 
     @Override
     public void onConnectionChange(final PeerConnection.PeerConnectionState newState) {
-        Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": PeerConnectionState changed to" + newState);
+        Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": PeerConnectionState changed to " + newState);
         this.stateHistory.add(newState);
         if (newState == PeerConnection.PeerConnectionState.CONNECTED) {
             this.sessionDuration.start();
@@ -1348,7 +1351,10 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         }
 
         final boolean neverConnected = !this.stateHistory.contains(PeerConnection.PeerConnectionState.CONNECTED);
-        final boolean failedOrDisconnected = Arrays.asList(PeerConnection.PeerConnectionState.FAILED, PeerConnection.PeerConnectionState.DISCONNECTED).contains(newState);
+        final boolean failedOrDisconnected = Arrays.asList(
+                PeerConnection.PeerConnectionState.FAILED,
+                PeerConnection.PeerConnectionState.DISCONNECTED
+        ).contains(newState);
 
 
         if (neverConnected && failedOrDisconnected) {
@@ -1356,7 +1362,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
                 Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": not sending session-terminate after connectivity error because session is already in state " + this.state);
                 return;
             }
-            new Thread(this::closeWebRTCSessionAfterFailedConnection).start();
+            webRTCWrapper.execute(this::closeWebRTCSessionAfterFailedConnection);
         } else if (newState == PeerConnection.PeerConnectionState.FAILED) {
             Log.d(Config.LOGTAG, "attempting to restart ICE");
             webRTCWrapper.restartIce();
@@ -1367,6 +1373,33 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
     @Override
     public void onRenegotiationNeeded() {
         Log.d(Config.LOGTAG, "onRenegotiationNeeded()");
+        this.webRTCWrapper.execute(this::renegotiate);
+    }
+
+    private void renegotiate() {
+        this.webRTCWrapper.setIsReadyToReceiveIceCandidates(false);
+        try {
+            final SessionDescription sessionDescription = setLocalSessionDescription();
+            final RtpContentMap rtpContentMap = RtpContentMap.of(sessionDescription);
+            setRenegotiatedContentMap(rtpContentMap);
+            this.webRTCWrapper.setIsReadyToReceiveIceCandidates(true);
+        } catch (final Exception e) {
+            Log.d(Config.LOGTAG, "failed to renegotiate", e);
+            //TODO send some sort of failure (comparable to when initiating)
+        }
+    }
+
+    private void setRenegotiatedContentMap(final RtpContentMap rtpContentMap) {
+        if (isInitiator()) {
+            this.initiatorRtpContentMap = rtpContentMap;
+        } else {
+            this.responderRtpContentMap = rtpContentMap;
+        }
+    }
+
+    private SessionDescription setLocalSessionDescription() throws ExecutionException, InterruptedException {
+        final org.webrtc.SessionDescription sessionDescription = this.webRTCWrapper.setLocalDescription().get();
+        return SessionDescription.parse(sessionDescription.description);
     }
 
     private void closeWebRTCSessionAfterFailedConnection() {

src/main/java/eu/siacs/conversations/xmpp/jingle/WebRTCWrapper.java

@@ -45,8 +45,13 @@ import org.webrtc.voiceengine.WebRtcAudioEffects;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
+import java.util.Queue;
 import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -59,6 +64,8 @@ public class WebRTCWrapper {
 
     private static final String EXTENDED_LOGGING_TAG = WebRTCWrapper.class.getSimpleName();
 
+    private final ExecutorService executorService = Executors.newSingleThreadExecutor();
+
     //we should probably keep this in sync with: https://github.com/signalapp/Signal-Android/blob/master/app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java#L296
     private static final Set<String> HARDWARE_AEC_BLACKLIST = new ImmutableSet.Builder<String>()
             .add("Pixel")
@@ -79,6 +86,8 @@ public class WebRTCWrapper {
     private static final int CAPTURING_MAX_FRAME_RATE = 30;
 
     private final EventCallback eventCallback;
+    private final AtomicBoolean readyToReceivedIceCandidates = new AtomicBoolean(false);
+    private final Queue<IceCandidate> iceCandidates = new LinkedList<>();
     private final AppRTCAudioManager.AudioManagerEvents audioManagerEvents = new AppRTCAudioManager.AudioManagerEvents() {
         @Override
         public void onAudioDeviceChanged(AppRTCAudioManager.AudioDevice selectedAudioDevice, Set<AppRTCAudioManager.AudioDevice> availableAudioDevices) {
@@ -125,7 +134,11 @@ public class WebRTCWrapper {
 
         @Override
         public void onIceCandidate(IceCandidate iceCandidate) {
+            if (readyToReceivedIceCandidates.get()) {
                 eventCallback.onIceCandidate(iceCandidate);
+            } else {
+                iceCandidates.add(iceCandidate);
+            }
         }
 
         @Override
@@ -294,7 +307,14 @@ public class WebRTCWrapper {
     }
 
     void restartIce() {
-        requirePeerConnection().restartIce();
+        executorService.execute(()-> requirePeerConnection().restartIce());
+    }
+
+    public void setIsReadyToReceiveIceCandidates(final boolean ready) {
+        readyToReceivedIceCandidates.set(ready);
+        while(ready && iceCandidates.peek() != null) {
+            eventCallback.onIceCandidate(iceCandidates.poll());
+        }
     }
 
     synchronized void close() {
@@ -528,6 +548,10 @@ public class WebRTCWrapper {
         return appRTCAudioManager;
     }
 
+    void execute(final Runnable command) {
+        executorService.execute(command);
+    }
+
     public interface EventCallback {
         void onIceCandidate(IceCandidate iceCandidate);