Stage 2: Add optional UniTask surface behind LIVEKIT_UNITASK

Runtime/Scripts/UniTask/YieldInstructionUniTaskExtensions.cs

@@ -0,0 +1,93 @@
+#if LIVEKIT_UNITASK
+using System.Threading;
+using Cysharp.Threading.Tasks;
+
+namespace LiveKit
+{
+    /// <summary>
+    /// Bridges the SDK's <see cref="YieldInstruction"/> / <see cref="StreamYieldInstruction"/>
+    /// surface to UniTask, adding <see cref="CancellationToken"/> support. Available only when
+    /// the <c>com.cysharp.unitask</c> package is installed; the assembly is otherwise excluded
+    /// via a defineConstraint on <c>LIVEKIT_UNITASK</c>.
+    /// </summary>
+    public static class YieldInstructionUniTaskExtensions
+    {
+        /// <summary>
+        /// Wraps the instruction as a <see cref="UniTask"/>. The task completes when the
+        /// instruction's <see cref="YieldInstruction.IsDone"/> transitions to true, or
+        /// faults with <see cref="System.OperationCanceledException"/> if the token fires
+        /// first.
+        /// </summary>
+        /// <remarks>
+        /// Cancellation has "abandon awaiter" semantics: the underlying FFI request keeps
+        /// running and any result is discarded. Wire-level cancellation is not yet
+        /// supported. Error inspection stays on the instruction itself — the awaiter does
+        /// not throw on <see cref="YieldInstruction.IsError"/>, matching the existing
+        /// <c>yield return</c> / <c>await</c> behavior.
+        /// </remarks>
+        public static UniTask AsUniTask(this YieldInstruction instruction, CancellationToken cancellationToken = default)
+        {
+            if (instruction == null) throw new System.ArgumentNullException(nameof(instruction));
+            if (instruction.IsDone) return UniTask.CompletedTask;
+            if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled(cancellationToken);
+
+            var source = new UniTaskCompletionSource();
+            CancellationTokenRegistration registration = default;
+
+            if (cancellationToken.CanBeCanceled)
+            {
+                registration = cancellationToken.Register(static state =>
+                {
+                    var s = (UniTaskCompletionSource)state;
+                    s.TrySetCanceled();
+                }, source);
+            }
+
+            // YieldInstruction.RegisterContinuation fires the callback exactly once and is
+            // race-safe between FFI-thread completion and main-thread registration. Either
+            // TrySetResult or TrySetCanceled wins; the loser is a no-op.
+            instruction.GetAwaiter().OnCompleted(() =>
+            {
+                registration.Dispose();
+                source.TrySetResult();
+            });
+
+            return source.Task;
+        }
+
+        /// <summary>
+        /// UniTask-bridged equivalent of awaiting a <see cref="StreamYieldInstruction"/> once.
+        /// Call <see cref="StreamYieldInstruction.Reset"/> between chunks; each
+        /// <c>AsUniTask</c> call awaits the next chunk or end-of-stream.
+        /// </summary>
+        public static UniTask AsUniTask(this StreamYieldInstruction instruction, CancellationToken cancellationToken = default)
+        {
+            if (instruction == null) throw new System.ArgumentNullException(nameof(instruction));
+            // GetAwaiter().IsCompleted folds together IsCurrentReadDone || IsEos and is
+            // the only public way to check the combined state from outside the LiveKit asm.
+            if (instruction.GetAwaiter().IsCompleted) return UniTask.CompletedTask;
+            if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled(cancellationToken);
+
+            var source = new UniTaskCompletionSource();
+            CancellationTokenRegistration registration = default;
+
+            if (cancellationToken.CanBeCanceled)
+            {
+                registration = cancellationToken.Register(static state =>
+                {
+                    var s = (UniTaskCompletionSource)state;
+                    s.TrySetCanceled();
+                }, source);
+            }
+
+            instruction.GetAwaiter().OnCompleted(() =>
+            {
+                registration.Dispose();
+                source.TrySetResult();
+            });
+
+            return source.Task;
+        }
+    }
+}
+#endif

Runtime/Scripts/UniTask/livekit.unity.Runtime.UniTask.asmdef

@@ -0,0 +1,25 @@
+{
+    "name": "LiveKit.UniTask",
+    "rootNamespace": "LiveKit.UniTaskExtensions",
+    "references": [
+        "LiveKit",
+        "UniTask"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [
+        "LIVEKIT_UNITASK"
+    ],
+    "versionDefines": [
+        {
+            "name": "com.cysharp.unitask",
+            "expression": "2.0.0",
+            "define": "LIVEKIT_UNITASK"
+        }
+    ],
+    "noEngineReferences": false
+}

Samples~/Meet/Assets/Runtime/MeetManager.cs

@@ -1,5 +1,6 @@
-using System.Collections;
 using System.Collections.Generic;
+using System.Threading;
+using Cysharp.Threading.Tasks;
 using UnityEngine;
 using UnityEngine.UI;
 using LiveKit;
@@ -97,9 +98,14 @@ private void OnDestroy()
 
     #region UI Callbacks
 
+    // Action-compatible button handlers; the async work fires-and-forgets via Forget()
+    // so exceptions are surfaced through UniTask's tracker instead of swallowed by
+    // async void. Cancellation is tied to the MonoBehaviour lifetime via
+    // GetCancellationTokenOnDestroy so scene change / app quit aborts in-flight FFI awaits.
+
     private void OnStartCall()
     {
-        StartCoroutine(ConnectToRoom());
+        ConnectToRoom(this.GetCancellationTokenOnDestroy()).Forget();
     }
 
     private void OnEndCall()
@@ -116,7 +122,7 @@ private void OnEndCall()
     private void OnToggleCamera()
     {
         if (!_cameraActive)
-            StartCoroutine(PublishLocalCamera());
+            PublishLocalCamera(this.GetCancellationTokenOnDestroy()).Forget();
         else
             UnpublishLocalCamera();
     }
@@ -125,7 +131,7 @@ private void OnToggleMicrophone()
     {
         if (!_microphoneActive)
         {
-            StartCoroutine(PublishLocalMicrophone());
+            PublishLocalMicrophone(this.GetCancellationTokenOnDestroy()).Forget();
             buttonBar.SetMicrophoneOn(true);
         }
         else
@@ -147,17 +153,17 @@ private void OnPublishData()
 
     #region Connection
 
-    private IEnumerator ConnectToRoom()
+    private async UniTask ConnectToRoom(CancellationToken cancellationToken)
     {
-        if (_room != null) yield break;
+        if (_room != null) return;
 
         var fetch = _tokenSourceComponent.FetchConnectionDetails(new TokenSourceFetchOptions());
-        yield return fetch;
+        await fetch.AsUniTask(cancellationToken);
 
         if (fetch.IsError)
         {
             Debug.LogError($"Failed to fetch connection details: {fetch.Exception?.Message}");
-            yield break;
+            return;
         }
 
         var details = fetch.Result;
@@ -172,13 +178,13 @@ private IEnumerator ConnectToRoom()
         _room.DataReceived += OnDataReceived;
 
         var connect = _room.Connect(details.ServerUrl, details.ParticipantToken, new RoomOptions());
-        yield return connect;
+        await connect.AsUniTask(cancellationToken);
 
         if (connect.IsError)
         {
             Debug.LogError("LiveKit connection failed");
             _room = null;
-            yield break;
+            return;
         }
 
         Debug.Log($"Connected to {_room.Name}");
@@ -390,14 +396,19 @@ private void OnTrackUnmuted(TrackPublication publication, Participant participan
 
     #region Local Camera
 
-    private IEnumerator PublishLocalCamera()
+    private async UniTask PublishLocalCamera(CancellationToken cancellationToken)
     {
-        if (_cameraActive) yield break;
+        if (_cameraActive) return;
 
         if (_webCamTexture == null)
-            yield return CameraDeviceProvider.Open(frameRate, t => _webCamTexture = t);
+        {
+            // CameraDeviceProvider.Open is still a plain IEnumerator (it touches Unity's
+            // WebCamTexture lifecycle), so bridge it through UniTask's IEnumerator adapter.
+            await CameraDeviceProvider.Open(frameRate, t => _webCamTexture = t)
+                .ToUniTask(cancellationToken: cancellationToken);
+        }
 
-        if (_webCamTexture == null) yield break;
+        if (_webCamTexture == null) return;
 
         EnsureParticipantTile(_localId);
         var tile = _participantTiles[_localId];
@@ -414,9 +425,9 @@ private IEnumerator PublishLocalCamera()
         };
 
         var publish = _room.LocalParticipant.PublishTrack(_localVideoTrack, options);
-        yield return publish;
+        await publish.AsUniTask(cancellationToken);
 
-        if (publish.IsError) yield break;
+        if (publish.IsError) return;
 
         source.TextureReceived += tex =>
         {
@@ -427,6 +438,7 @@ private IEnumerator PublishLocalCamera()
         _cameraActive = true;
         _localRtcVideoSource = source;
         source.Start();
+        // Long-running per-frame pump — keep on the coroutine driver, not awaitable.
         StartCoroutine(source.Update());
 
         buttonBar.SetCameraOn(true);
@@ -449,9 +461,9 @@ private void UnpublishLocalCamera()
 
     #region Local Microphone
 
-    private IEnumerator PublishLocalMicrophone()
+    private async UniTask PublishLocalMicrophone(CancellationToken cancellationToken)
     {
-        if (_audioObjects.ContainsKey(LocalAudioTrackName)) yield break;
+        if (_audioObjects.ContainsKey(LocalAudioTrackName)) return;
 
         Microphone.Start(null, true, 10, 44100);
 
@@ -469,9 +481,9 @@ private IEnumerator PublishLocalMicrophone()
         };
 
         var publish = _room.LocalParticipant.PublishTrack(_localAudioTrack, options);
-        yield return publish;
+        await publish.AsUniTask(cancellationToken);
 
-        if (publish.IsError) yield break;
+        if (publish.IsError) return;
 
         _microphoneActive = true;
         _audioObjects[LocalAudioTrackName] = audioObject;

Samples~/Meet/Packages/manifest.json

@@ -1,5 +1,6 @@
 {
   "dependencies": {
+    "com.cysharp.unitask": "https://github.com/Cysharp/UniTask.git?path=src/UniTask/Assets/Plugins/UniTask",
     "com.unity.collab-proxy": "2.2.0",
     "com.unity.feature.2d": "2.0.0",
     "com.unity.ide.rider": "3.0.27",

Samples~/Meet/Packages/packages-lock.json

@@ -1,5 +1,12 @@
 {
   "dependencies": {
+    "com.cysharp.unitask": {
+      "version": "https://github.com/Cysharp/UniTask.git?path=src/UniTask/Assets/Plugins/UniTask",
+      "depth": 0,
+      "source": "git",
+      "dependencies": {},
+      "hash": "e5acc106ee196bc5a32fb14cdf2987b0f96d11e0"
+    },
     "com.unity.2d.animation": {
       "version": "9.1.0",
       "depth": 1,

Tests/PlayMode/UniTask/LiveKit.PlayModeTests.UniTask.asmdef

@@ -0,0 +1,31 @@
+{
+    "name": "PlayModeTests.UniTask",
+    "rootNamespace": "LiveKit.PlayModeTests.UniTask",
+    "references": [
+        "UnityEngine.TestRunner",
+        "UnityEditor.TestRunner",
+        "LiveKit",
+        "LiveKit.UniTask",
+        "UniTask"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": true,
+    "precompiledReferences": [
+        "nunit.framework.dll"
+    ],
+    "autoReferenced": false,
+    "defineConstraints": [
+        "UNITY_INCLUDE_TESTS",
+        "LIVEKIT_UNITASK"
+    ],
+    "versionDefines": [
+        {
+            "name": "com.cysharp.unitask",
+            "expression": "2.0.0",
+            "define": "LIVEKIT_UNITASK"
+        }
+    ],
+    "noEngineReferences": false
+}