Memory Leak in LiveKitWebRTC when streaming via BufferCapturer

[Mt-Perazim]

Hi @pblazej and @hiroshihorie , this is a follow-up to my previous report:
Previous issue: Memory Leaking - High memory after Room.disconnect #827

I can now provide a minimal, runnable LiveKit + ARKit reproduction project that isolates the leak.
This project contains only the essential components from the LiveKit example plus a minimal custom AR → BufferCapturer bridge.
This issue focuses exclusively on internal leaks.

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Summary

The minimal project supports two Room lifecycle modes:

• Global shared Room instance (matching the original LiveKit Example)
  → Reproduces one leak(LiveKitWebRTC)

• Per-connection mode (fresh Room() for each join)
  → After a leave + rejoin, Instruments reports more than 24 leaks

In the per-connection mode, the previous Room instance becomes unreachable from the app side (replaced by a new placeholder Room), but internal LiveKit objects remain alive and are reported as leaks.

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Minimal Reproduction Project

@pblazej and @hiroshihorie, I invited you to the private GitHub project.

The project is a very small SwiftUI app based on these components from the official LiveKit examples:

• RoomSwitchView
• RoomContextView
• ParticipantView
• ConnectView
• LKButton, LKTextField
• SecureStore
• Participant+Helper
• ExampleRoomMessage
• ConnectionHistory
• Bundle helper

Added on top:

• A minimal ARKit → BufferCapturer bridge (ARVideoCapturer) publishing AR frames as a LocalVideoTrack.

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How to Run the Minimal Setup

1. Clone the provided sample project.

2. Configure your LiveKit server URL and token in RoomContext (file: RoomContext.swift):

   url = "wss://<your-livekit-host>.livekit.cloud"
   token = "<your-jwt-token>"
   

3. Open LiveKit_ARKit_MinimalSetupApp.swift.

4. Choose one of the two lifecycle configurations:

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A. Global shared instance (original example behavior)

RoomContextView(lifecycleMode: .globalSharedInstance)

→ Produces one reproducible leak after leaving the room.

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B. New Room per join (perConnectionNewInstance)

RoomContextView(lifecycleMode: .perConnectionNewInstance)

→ Produces more than 24 leaks after rejoining a session.

In this mode:

• connect() creates a fresh Room().
• After disconnect(), the previous Room is replaced by a new placeholder Room
  (alternatively it could be set to nil, but that's not required for the repro).

5. Run the application
6. Join a session
7. Activate the camera (top right corner)
8. Leave the session
9. Repeat joining a session

However, the previous Room instance is no longer referenced anywhere in the app.
Despite that, Instruments shows multiple LiveKit internal structures as leaked
(DataChannel / Async / Delegate / StateSync objects, etc.).