GLSP Server Error when closing GLSP Eclipse Editor #556

[jfaltermeier]

This is a proposed fix for eclipse-glsp/glsp#556

The idea behind the fix is to a) make access to the clientidToDiagramEditor Map thread safe and b) to turn off the ActionDispatcher when the editor is about to be closed. This way any actions that are still sent from the client are ignored after the editor was removed from the GLSPEditorRegistry.

[jfaltermeier]

@tortmayr Could you please have a look at this fix? Is there a better way to dispose communication when the editor is closed?

[tortmayr]

Thanks, in general the changes look good to me.
However, I would not just dispose the ActionDispatcher in the notifyAboutToBeDisposed method. The cleaner solution would be to correctly dispose the client session here using the ClientSessionManager:

   public void notifyAboutToBeDisposed() {
      // we are about to be disposed. don't send and accept actions anymore
      getClientSessionManager().thenAccept(sessionManager -> sessionManager.disposeClientSession(getClientId()));
   }

   protected CompletableFuture<ClientSessionManager> getClientSessionManager() {
      return getInstance(ClientSessionManager.class);
   }

This will dispose the action dispatcher and any other running threads (e.g. the ModelSourceWatcher)

[tortmayr]

LGTM 👍 Thanks!