fix(whisper): Fixes synchronization issue.

Sending audio while closing:

2025-05-12 19:52:17.247 SEVERE: [49476] WhisperWebsocket.onClose#280: [ctx=1747078888901486844622] Websocket closed: 1012 reason:null
2025-05-12 19:52:17.248 INFO: [205] org.eclipse.jetty.util.component.Graceful.shutdown: Shutdown WebSocketClient@15bc7f4b[coreClient=WebSocketCoreClient@2796144a{STARTED},openSessions.size=1]
2025-05-12 19:52:18.009 SEVERE: [49537] net.java.sip.communicator.util.UtilActivator.uncaughtException: An uncaught exception occurred in thread=Thread[pool-51-thread-1,5,main], and message was: Cannot invoke "java.util.Map.containsKey(Object)" because "this.participants" is null
java.lang.NullPointerException: Cannot invoke "java.util.Map.containsKey(Object)" because "this.participants" is null
        at org.jitsi.jigasi.transcription.WhisperWebsocket.addParticipantIfNotExists(WhisperWebsocket.java:522)
        at org.jitsi.jigasi.transcription.WhisperWebsocket.addListener(WhisperWebsocket.java:533)
        at org.jitsi.jigasi.transcription.WhisperTranscriptionService$WhisperWebsocketStreamingSession.addTranscriptionListener(WhisperTranscriptionService.java:193)
        at org.jitsi.jigasi.transcription.Participant.lambda$sendRequest$1(Participant.java:717)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:840)
2025-05-12 19:52:19.470 SEVERE: [49680] net.java.sip.communicator.util.UtilActivator.uncaughtException: An uncaught exception occurred in thread=Thread[p

Author: damencho

src/main/java/org/jitsi/jigasi/transcription/WhisperWebsocket.java

@@ -260,7 +260,7 @@ private synchronized void reconnect()
     }
 
     @OnWebSocketClose
-    public void onClose(int statusCode, String reason)
+    public synchronized void onClose(int statusCode, String reason)
     {
         logger.error("Websocket closed: " + statusCode + " reason:" + reason
             + " isRunning: " + isRunning() + " isOpen:" + (wsSession != null && wsSession.isOpen()));
@@ -438,14 +438,14 @@ public void disconnectParticipant(String participantId, Consumer<Boolean> callba
 
     private void disconnectParticipantInternal(String participantId, Consumer<Boolean> callback)
     {
-        if (ended() && !isRunning())
-        {
-            callback.accept(true);
-            return;
-        }
-
         synchronized (this)
         {
+            if (ended() && !isRunning())
+            {
+                callback.accept(true);
+                return;
+            }
+
             if (participants.containsKey(participantId))
             {
                 participants.remove(participantId);