Events Being Dropped on Connection

[stephen-derosa]

Overview

• Adds integration tests to validate events after connection
• RoomReadyEventRequest which gets called after ffi handle is created

Testing

• new integration test
• manual addition of a sleep before the making the request shows that we still get the events

[xianshijing-lk]

lgtm.

can you search FfiClient::instance().AddListener() in our code base, and make sure we are using the same patter for all use cases ?

[stephen-derosa]

lgtm.

can you search FfiClient::instance().AddListener() in our code base, and make sure we are using the same patter for all use cases ?

@xianshijing-lk :
Done. The production call sites are Room, AudioStream, VideoStream, and DataTrackStream.
AudioStream and VideoStream already install their FFI listener before sending the FFI request that creates the stream, then remove it in close()/destruction. DataTrackStream receives an existing subscription handle, then installs the listener before read() starts requesting frames. Room now follows the same event-safety pattern by installing the listener before connectAsync(), and it removes the listener on failed Connect() so reconnect does not leave duplicate callbacks.
I didn’t find any other AddListener() usage that needs a matching change.

[stephen-derosa]

new unit tests shows that the race condition does still exist. We are going to move forward with a "ready" signal from the client sdk to the rust sdk which signals to rust that the client is ready for room events. see this slack thread for discussion: https://live-kit.slack.com/archives/C02EWQYP4KE/p1778708015361339?thread_ts=1778285077.084319&cid=C02EWQYP4KE

[Copilot]

Pull request overview

This PR addresses a connection-time race where room events can be dropped by registering the FFI event listener earlier in Room::Connect() and explicitly notifying the Rust core when the C++ room is ready to receive/flush room events. It also adds new integration/stress coverage focused on listener cleanup and late-join publication callbacks.

Changes:

• Register the FFI listener before connectAsync() and send a new ready_for_room_event request after the room handle/state is fully initialized.
• Add integration tests validating that failed/invalid connects and reconnect flows don’t leave duplicate listeners (no duplicate participant callbacks).
• Add integration/stress tests validating late-join publication/subscription callback ordering and a concurrent reconnect/publish stress scenario.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/room.cpp	Installs the FFI listener earlier and sends a “ready” request to flush room events once initialization completes; improves failure cleanup.
src/ffi_client.cpp	Minor formatting cleanup.
src/tests/stress/test_room_listener_race_stress.cpp	New stress test for concurrent failed connect/destroy/reconnect and data track publishing.
src/tests/integration/test_room_listener_cleanup.cpp	New integration tests to ensure failed/invalid connects don’t leak/duplicate listeners and callbacks.
src/tests/integration/test_late_join_track_publication.cpp	New parameterized integration tests validating late-join publication/subscription callback invariants for audio/video/data tracks.
AGENTS.md	Adds guidance about not updating generated code (spelling nit present).
.gitignore	Ignores user_stories.

Comments suppressed due to low confidence (2)

src/tests/integration/test_room_listener_cleanup.cpp:115

• Tests should skip (GTEST_SKIP / skipIfNotConfigured) when LIVEKIT_* env vars are not set, rather than throwing. Throwing here will fail the entire integration test run in environments without credentials.

  if (!config_.available) {
    throw std::runtime_error("LIVEKIT_URL, LIVEKIT_TOKEN_A, and LIVEKIT_TOKEN_B not set");
  }

src/tests/integration/test_room_listener_cleanup.cpp:123

• Tests should skip (GTEST_SKIP / skipIfNotConfigured) when LIVEKIT_* env vars are not set, rather than throwing. Throwing here will fail the entire integration test run in environments without credentials.

  if (!config_.available) {
    throw std::runtime_error("LIVEKIT_URL, LIVEKIT_TOKEN_A, and LIVEKIT_TOKEN_B not set");
  }

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