Room::disconnect() blocks and triggers reconnect/crash when offline

[tomakor549]

LiveKit C++ SDK Version

v1.4.0

Platform

Linux x86_64

OS Version

Ubuntu 26

Compiler & Version

g++ 15.2.0

CMake Version

4.2.3

How are you using the SDK?

Building from source (build.sh / build.cmd)

Issue Description

Calling Room::disconnect(DisconnectReason::ClientInitiated) while the network is down blocks the calling thread. When connectivity returns, internal rtc_engine attempts reconnect, fails with StateMismatch, and the process can crash.

shutdown function part:

void LiveKitService::shutdown() {
//...
qCInfo(LiveKitLog) << "_livekit_audio_source.reset()...";
_livekit_audio_source.reset();
qCInfo(LiveKitLog) << "_livekit_video_source.reset()...";
_livekit_video_source.reset();
qCInfo(LiveKitLog) << "_delegate.reset()...";
_delegate.reset();

if (_livekit_initialized.exchange(false)) {
qCInfo(LiveKitLog) << "_room.disconnect...";
_room.disconnect(DisconnectReason::ClientInitiated);
}
}

Steps to Reproduce

1. Connect to a LiveKit room
2. Disable network (or unplug)
3. Call _room.disconnect(DisconnectReason::ClientInitiated)
4. Observe: thread blocks
5. Re-enable network
6. Disconnect unblocks, then reconnect errors appear; crash may follow

Logs

##Example LOGS
[2026-07-28 19:22:34.077][LiveKitLog][INFO][53865][livekit::LiveKitService::shutdown:165]: _room.disconnect...
[2026-07-28T17:22:49Z ERROR livekit_api::signal_client::signal_stream] unhandled websocket message Err(Io(Os { code: 104, kind: ConnectionReset, message: "Connection reset by peer" }))
[2026-07-28T17:22:49Z ERROR livekit::rtc_engine] resuming connection failed: signal failure: server sent leave during reconnect: reason=StateMismatch, action=Reconnect
[2026-07-28T17:22:49Z ERROR livekit::rtc_engine] failed to reconnect to the livekit room
19:22:50: The command "..." terminated abnormally.

[alan-george-lk]

Thanks for flagging this -- will get back to you ASAP.

[tomakor549]

There is a similar problem with unpublishTrack. After internet disconnection, calling unpublishTrack blocks the calling thread indefinitely and never returns.

videoTrack is a std::shared_ptr<livekit::LocalVideoTrack> (local video track).

try {
  if (auto participant = _room.localParticipant().lock()) {
    for (const auto& [sid, pub] : participant->trackPublications()) {
      if (pub->name() == videoTrack->name()) {
        participant->unpublishTrack(sid);  // ← hangs here after network drop
        break;
      }
    }
  }
} catch (const std::exception& e) {
  qCWarning(LiveKitLog()) << "Error during unpublishing track:" << e.what();
}