| 1 | UniTask is a readonly partial struct (value type). Once awaited, its IUniTaskSource is recycled; awaiting the same UniTask variable twice throws. Use .Preserve() to obtain a memoized copy that can be awaited multiple times. | UniTask.cs:34, UniTask.cs:103-113 |
| 2 | A UniTask returned by a method must be either awaited, .Forget()ed, or .AttachExternalCancellation(token)ed. Orphan UniTasks silently swallow exceptions into UniTaskScheduler.UnobservedTaskException. | UniTaskScheduler.cs:13, UniTaskVoid.cs:11-17 |
| 3 | PlayerLoopTiming defines 16 timing slots (2020.2+; 14 on older Unity). Default UniTask.Yield() / UniTask.Delay uses PlayerLoopTiming.Update. Mixing LastPostLateUpdate with legacy WaitForEndOfFrame coroutines changes observed frame ordering. | PlayerLoopHelper.cs:71-99 |
| 4 | UniTask.Delay(int ms, DelayType, PlayerLoopTiming, CancellationToken, bool cancelImmediately) accepts DelayType.DeltaTime / UnscaledDeltaTime / Realtime. The old bool ignoreTimeScale overload still exists but mixes semantics — prefer the DelayType overload for new code. | UniTask.Delay.cs:12-20, UniTask.Delay.cs:147-165 |
| 5 | this.GetCancellationTokenOnDestroy() is defined for MonoBehaviour, GameObject, and Component in AsyncTriggerExtensions. Plain C# classes do NOT receive this extension — they must own a CancellationTokenSource explicitly. | Triggers/AsyncTriggerExtensions.cs:14,22,28 |
| 6 | UniTask.WhenAll(params UniTask[] tasks) and the IEnumerable<UniTask> overload both exist. Semantically match Task.WhenAll but are zero-alloc when tasks are UniTask-native. WhenAny returns (winnerIndex, result) tuple for UniTask<T>. | UniTask.WhenAll.cs:12,22,31,41, UniTask.WhenAny.cs |
| 7 | AsyncOperation.ToUniTask(IProgress<float>, PlayerLoopTiming, CancellationToken) is the canonical adapter. await operation works too but silently leaks the progress callback if you also set operation.completed += …. | UnityAsyncExtensions.cs |
| 8 | UniTaskCompletionSource and UniTaskCompletionSource<T> support TrySetResult / TrySetException / TrySetCanceled. Once any of the three succeeds, subsequent calls return false — they do not throw. | UniTaskCompletionSource.cs:573,610,754,792 |
| 9 | UniTask.SwitchToThreadPool() and UniTask.Run(...) are compile-time available on all platforms BUT throw NotSupportedException at runtime on WebGL. Guard with `#if !UNITY_WEBGL | |
| 10 | Returning async UniTaskVoid is the fire-and-forget idiom that lets await be used INSIDE the method. async void methods cannot return UniTask — a common compile error when porting from Task. | UniTaskVoid.cs:11-17, UniTask.Factory.cs:112-131 |
