diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
index 069ee5a..dc24ad0 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs
@@ -28,22 +28,15 @@ namespace Cysharp.Threading.Tasks
 
         public static UniTask WithCancellation(this AsyncOperation asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled(cancellationToken);
-                if (asyncOperation.isDone) return UniTask.CompletedTask;
-                return new UniTask(AsyncOperationCallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static UniTask ToUniTask(this AsyncOperation asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static UniTask ToUniTask(this AsyncOperation asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled(cancellationToken);
             if (asyncOperation.isDone) return UniTask.CompletedTask;
-            return new UniTask(AsyncOperationConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new UniTask(AsyncOperationConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct AsyncOperationAwaiter : ICriticalNotifyCompletion
@@ -86,106 +79,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class AsyncOperationCallbackHandlerSource : IUniTaskSource, ITaskPoolNode<AsyncOperationCallbackHandlerSource>
-        {
-            static TaskPool<AsyncOperationCallbackHandlerSource> pool;
-            AsyncOperationCallbackHandlerSource nextNode;
-            public ref AsyncOperationCallbackHandlerSource NextNode => ref nextNode;
-
-            static AsyncOperationCallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(AsyncOperationCallbackHandlerSource), () => pool.Size);
-            }
-
-            AsyncOperation asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<AsyncUnit> core;
-
-            AsyncOperationCallbackHandlerSource()
-            {
-            }
-
-            public static IUniTaskSource Create(AsyncOperation asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new AsyncOperationCallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (AsyncOperationCallbackHandlerSource)state;
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public void GetResult(short token)
-            {
-                try
-                {
-                    core.GetResult(token);
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-                core.TrySetResult(AsyncUnit.Default);
-            }
-        }
-
         sealed class AsyncOperationConfiguredSource : IUniTaskSource, IPlayerLoopItem, ITaskPoolNode<AsyncOperationConfiguredSource>
         {
             static TaskPool<AsyncOperationConfiguredSource> pool;
@@ -200,14 +93,18 @@ namespace Cysharp.Threading.Tasks
             AsyncOperation asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<AsyncUnit> core;
 
+            Action<AsyncOperation> continuationAction;
+
             AsyncOperationConfiguredSource()
             {
             }
 
-            public static IUniTaskSource Create(AsyncOperation asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static IUniTaskSource Create(AsyncOperation asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -222,6 +119,22 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (AsyncOperationConfiguredSource)state;
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -285,11 +198,33 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+                    else
+                    {
+                        core.TrySetResult(AsyncUnit.Default);
+                    }
+                }
+            }
         }
 
         #endregion
@@ -309,22 +244,15 @@ namespace Cysharp.Threading.Tasks
 
         public static UniTask<UnityEngine.Object> WithCancellation(this ResourceRequest asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityEngine.Object>(cancellationToken);
-                if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.asset);
-                return new UniTask<UnityEngine.Object>(ResourceRequestCallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static UniTask<UnityEngine.Object> ToUniTask(this ResourceRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static UniTask<UnityEngine.Object> ToUniTask(this ResourceRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityEngine.Object>(cancellationToken);
             if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.asset);
-            return new UniTask<UnityEngine.Object>(ResourceRequestConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new UniTask<UnityEngine.Object>(ResourceRequestConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct ResourceRequestAwaiter : ICriticalNotifyCompletion
@@ -371,110 +299,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class ResourceRequestCallbackHandlerSource : IUniTaskSource<UnityEngine.Object>, ITaskPoolNode<ResourceRequestCallbackHandlerSource>
-        {
-            static TaskPool<ResourceRequestCallbackHandlerSource> pool;
-            ResourceRequestCallbackHandlerSource nextNode;
-            public ref ResourceRequestCallbackHandlerSource NextNode => ref nextNode;
-
-            static ResourceRequestCallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(ResourceRequestCallbackHandlerSource), () => pool.Size);
-            }
-
-            ResourceRequest asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<UnityEngine.Object> core;
-
-            ResourceRequestCallbackHandlerSource()
-            {
-            }
-
-            public static IUniTaskSource<UnityEngine.Object> Create(ResourceRequest asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource<UnityEngine.Object>.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new ResourceRequestCallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (ResourceRequestCallbackHandlerSource)state;
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public UnityEngine.Object GetResult(short token)
-            {
-                try
-                {
-                    return core.GetResult(token);
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-            void IUniTaskSource.GetResult(short token)
-            {
-                GetResult(token);
-            }
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-                core.TrySetResult(asyncOperation.asset);
-            }
-        }
-
         sealed class ResourceRequestConfiguredSource : IUniTaskSource<UnityEngine.Object>, IPlayerLoopItem, ITaskPoolNode<ResourceRequestConfiguredSource>
         {
             static TaskPool<ResourceRequestConfiguredSource> pool;
@@ -489,14 +313,18 @@ namespace Cysharp.Threading.Tasks
             ResourceRequest asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<UnityEngine.Object> core;
 
+            Action<AsyncOperation> continuationAction;
+
             ResourceRequestConfiguredSource()
             {
             }
 
-            public static IUniTaskSource<UnityEngine.Object> Create(ResourceRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static IUniTaskSource<UnityEngine.Object> Create(ResourceRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -511,6 +339,22 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (ResourceRequestConfiguredSource)state;
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -578,11 +422,33 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.asset);
+                    }
+                }
+            }
         }
 
         #endregion
@@ -603,22 +469,15 @@ namespace Cysharp.Threading.Tasks
 
         public static UniTask<UnityEngine.Object> WithCancellation(this AssetBundleRequest asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityEngine.Object>(cancellationToken);
-                if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.asset);
-                return new UniTask<UnityEngine.Object>(AssetBundleRequestCallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static UniTask<UnityEngine.Object> ToUniTask(this AssetBundleRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static UniTask<UnityEngine.Object> ToUniTask(this AssetBundleRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityEngine.Object>(cancellationToken);
             if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.asset);
-            return new UniTask<UnityEngine.Object>(AssetBundleRequestConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new UniTask<UnityEngine.Object>(AssetBundleRequestConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct AssetBundleRequestAwaiter : ICriticalNotifyCompletion
@@ -665,110 +524,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class AssetBundleRequestCallbackHandlerSource : IUniTaskSource<UnityEngine.Object>, ITaskPoolNode<AssetBundleRequestCallbackHandlerSource>
-        {
-            static TaskPool<AssetBundleRequestCallbackHandlerSource> pool;
-            AssetBundleRequestCallbackHandlerSource nextNode;
-            public ref AssetBundleRequestCallbackHandlerSource NextNode => ref nextNode;
-
-            static AssetBundleRequestCallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(AssetBundleRequestCallbackHandlerSource), () => pool.Size);
-            }
-
-            AssetBundleRequest asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<UnityEngine.Object> core;
-
-            AssetBundleRequestCallbackHandlerSource()
-            {
-            }
-
-            public static IUniTaskSource<UnityEngine.Object> Create(AssetBundleRequest asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource<UnityEngine.Object>.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new AssetBundleRequestCallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (AssetBundleRequestCallbackHandlerSource)state;
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public UnityEngine.Object GetResult(short token)
-            {
-                try
-                {
-                    return core.GetResult(token);
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-            void IUniTaskSource.GetResult(short token)
-            {
-                GetResult(token);
-            }
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-                core.TrySetResult(asyncOperation.asset);
-            }
-        }
-
         sealed class AssetBundleRequestConfiguredSource : IUniTaskSource<UnityEngine.Object>, IPlayerLoopItem, ITaskPoolNode<AssetBundleRequestConfiguredSource>
         {
             static TaskPool<AssetBundleRequestConfiguredSource> pool;
@@ -783,14 +538,18 @@ namespace Cysharp.Threading.Tasks
             AssetBundleRequest asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<UnityEngine.Object> core;
 
+            Action<AsyncOperation> continuationAction;
+
             AssetBundleRequestConfiguredSource()
             {
             }
 
-            public static IUniTaskSource<UnityEngine.Object> Create(AssetBundleRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static IUniTaskSource<UnityEngine.Object> Create(AssetBundleRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -805,6 +564,22 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (AssetBundleRequestConfiguredSource)state;
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -872,11 +647,33 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.asset);
+                    }
+                }
+            }
         }
 
         #endregion
@@ -898,22 +695,15 @@ namespace Cysharp.Threading.Tasks
 
         public static UniTask<AssetBundle> WithCancellation(this AssetBundleCreateRequest asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<AssetBundle>(cancellationToken);
-                if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.assetBundle);
-                return new UniTask<AssetBundle>(AssetBundleCreateRequestCallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static UniTask<AssetBundle> ToUniTask(this AssetBundleCreateRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static UniTask<AssetBundle> ToUniTask(this AssetBundleCreateRequest asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<AssetBundle>(cancellationToken);
             if (asyncOperation.isDone) return UniTask.FromResult(asyncOperation.assetBundle);
-            return new UniTask<AssetBundle>(AssetBundleCreateRequestConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new UniTask<AssetBundle>(AssetBundleCreateRequestConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct AssetBundleCreateRequestAwaiter : ICriticalNotifyCompletion
@@ -960,110 +750,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class AssetBundleCreateRequestCallbackHandlerSource : IUniTaskSource<AssetBundle>, ITaskPoolNode<AssetBundleCreateRequestCallbackHandlerSource>
-        {
-            static TaskPool<AssetBundleCreateRequestCallbackHandlerSource> pool;
-            AssetBundleCreateRequestCallbackHandlerSource nextNode;
-            public ref AssetBundleCreateRequestCallbackHandlerSource NextNode => ref nextNode;
-
-            static AssetBundleCreateRequestCallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(AssetBundleCreateRequestCallbackHandlerSource), () => pool.Size);
-            }
-
-            AssetBundleCreateRequest asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<AssetBundle> core;
-
-            AssetBundleCreateRequestCallbackHandlerSource()
-            {
-            }
-
-            public static IUniTaskSource<AssetBundle> Create(AssetBundleCreateRequest asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource<AssetBundle>.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new AssetBundleCreateRequestCallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (AssetBundleCreateRequestCallbackHandlerSource)state;
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public AssetBundle GetResult(short token)
-            {
-                try
-                {
-                    return core.GetResult(token);
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-            void IUniTaskSource.GetResult(short token)
-            {
-                GetResult(token);
-            }
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-                core.TrySetResult(asyncOperation.assetBundle);
-            }
-        }
-
         sealed class AssetBundleCreateRequestConfiguredSource : IUniTaskSource<AssetBundle>, IPlayerLoopItem, ITaskPoolNode<AssetBundleCreateRequestConfiguredSource>
         {
             static TaskPool<AssetBundleCreateRequestConfiguredSource> pool;
@@ -1078,14 +764,18 @@ namespace Cysharp.Threading.Tasks
             AssetBundleCreateRequest asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<AssetBundle> core;
 
+            Action<AsyncOperation> continuationAction;
+
             AssetBundleCreateRequestConfiguredSource()
             {
             }
 
-            public static IUniTaskSource<AssetBundle> Create(AssetBundleCreateRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static IUniTaskSource<AssetBundle> Create(AssetBundleCreateRequest asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -1100,6 +790,22 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (AssetBundleCreateRequestConfiguredSource)state;
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -1167,11 +873,33 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.assetBundle);
+                    }
+                }
+            }
         }
 
         #endregion
@@ -1193,24 +921,10 @@ namespace Cysharp.Threading.Tasks
 
         public static UniTask<UnityWebRequest> WithCancellation(this UnityWebRequestAsyncOperation asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityWebRequest>(cancellationToken);
-                if (asyncOperation.isDone)
-                {
-                    if (asyncOperation.webRequest.IsError())
-                    {
-                        return UniTask.FromException<UnityWebRequest>(new UnityWebRequestException(asyncOperation.webRequest));
-                    }
-                    return UniTask.FromResult(asyncOperation.webRequest);
-                }
-                return new UniTask<UnityWebRequest>(UnityWebRequestAsyncOperationCallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static UniTask<UnityWebRequest> ToUniTask(this UnityWebRequestAsyncOperation asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static UniTask<UnityWebRequest> ToUniTask(this UnityWebRequestAsyncOperation asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<UnityWebRequest>(cancellationToken);
@@ -1222,7 +936,7 @@ namespace Cysharp.Threading.Tasks
                 }
                 return UniTask.FromResult(asyncOperation.webRequest);
             }
-            return new UniTask<UnityWebRequest>(UnityWebRequestAsyncOperationConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new UniTask<UnityWebRequest>(UnityWebRequestAsyncOperationConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct UnityWebRequestAsyncOperationAwaiter : ICriticalNotifyCompletion
@@ -1277,118 +991,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class UnityWebRequestAsyncOperationCallbackHandlerSource : IUniTaskSource<UnityWebRequest>, ITaskPoolNode<UnityWebRequestAsyncOperationCallbackHandlerSource>
-        {
-            static TaskPool<UnityWebRequestAsyncOperationCallbackHandlerSource> pool;
-            UnityWebRequestAsyncOperationCallbackHandlerSource nextNode;
-            public ref UnityWebRequestAsyncOperationCallbackHandlerSource NextNode => ref nextNode;
-
-            static UnityWebRequestAsyncOperationCallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(UnityWebRequestAsyncOperationCallbackHandlerSource), () => pool.Size);
-            }
-
-            UnityWebRequestAsyncOperation asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<UnityWebRequest> core;
-
-            UnityWebRequestAsyncOperationCallbackHandlerSource()
-            {
-            }
-
-            public static IUniTaskSource<UnityWebRequest> Create(UnityWebRequestAsyncOperation asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource<UnityWebRequest>.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new UnityWebRequestAsyncOperationCallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (UnityWebRequestAsyncOperationCallbackHandlerSource)state;
-                        source.asyncOperation.webRequest.Abort();
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public UnityWebRequest GetResult(short token)
-            {
-                try
-                {
-                    return core.GetResult(token);
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-            void IUniTaskSource.GetResult(short token)
-            {
-                GetResult(token);
-            }
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-                if (asyncOperation.webRequest.IsError())
-                {
-                    core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
-                }
-                else
-                {
-                    core.TrySetResult(asyncOperation.webRequest);
-                }
-            }
-        }
-
         sealed class UnityWebRequestAsyncOperationConfiguredSource : IUniTaskSource<UnityWebRequest>, IPlayerLoopItem, ITaskPoolNode<UnityWebRequestAsyncOperationConfiguredSource>
         {
             static TaskPool<UnityWebRequestAsyncOperationConfiguredSource> pool;
@@ -1403,14 +1005,18 @@ namespace Cysharp.Threading.Tasks
             UnityWebRequestAsyncOperation asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<UnityWebRequest> core;
 
+            Action<AsyncOperation> continuationAction;
+
             UnityWebRequestAsyncOperationConfiguredSource()
             {
             }
 
-            public static IUniTaskSource<UnityWebRequest> Create(UnityWebRequestAsyncOperation asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static IUniTaskSource<UnityWebRequest> Create(UnityWebRequestAsyncOperation asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -1425,6 +1031,23 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (UnityWebRequestAsyncOperationConfiguredSource)state;
+                            source.asyncOperation.webRequest.Abort();
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -1500,11 +1123,37 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+                    else if (asyncOperation.webRequest.IsError())
+                    {
+                        core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.webRequest);
+                    }
+                }
+            }
         }
 
         #endregion
diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
index f74fa0b..105893d 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt
@@ -56,28 +56,10 @@ namespace Cysharp.Threading.Tasks
 
         public static <#= ToUniTaskReturnType(t.returnType) #> WithCancellation(this <#= t.typeName #> asyncOperation, bool handleImmediately, CancellationToken cancellationToken)
         {
-            if (handleImmediately)
-            {
-                Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
-                if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<#= IsVoid(t) ? "" : "<" + t.returnType + ">" #>(cancellationToken);
-<# if(IsUnityWebRequest(t)) { #>
-                if (asyncOperation.isDone)
-                {
-                    if (asyncOperation.webRequest.IsError())
-                    {
-                        return UniTask.FromException<UnityWebRequest>(new UnityWebRequestException(asyncOperation.webRequest));
-                    }
-                    return UniTask.FromResult(asyncOperation.webRequest);
-                }
-<# } else { #>
-                if (asyncOperation.isDone) return <#= IsVoid(t) ? "UniTask.CompletedTask" : $"UniTask.FromResult(asyncOperation.{t.returnField})" #>;
-<# } #>
-                return new <#= ToUniTaskReturnType(t.returnType) #>(<#= t.typeName #>CallbackHandlerSource.Create(asyncOperation, cancellationToken, out var token), token);
-            }
-            return ToUniTask(asyncOperation, cancellationToken: cancellationToken);
+            return ToUniTask(asyncOperation, handleImmediately: handleImmediately, cancellationToken: cancellationToken);
         }
 
-        public static <#= ToUniTaskReturnType(t.returnType) #> ToUniTask(this <#= t.typeName #> asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, CancellationToken cancellationToken = default(CancellationToken))
+        public static <#= ToUniTaskReturnType(t.returnType) #> ToUniTask(this <#= t.typeName #> asyncOperation, IProgress<float> progress = null, PlayerLoopTiming timing = PlayerLoopTiming.Update, bool handleImmediately = false, CancellationToken cancellationToken = default(CancellationToken))
         {
             Error.ThrowArgumentNullException(asyncOperation, nameof(asyncOperation));
             if (cancellationToken.IsCancellationRequested) return UniTask.FromCanceled<#= IsVoid(t) ? "" : "<" + t.returnType + ">" #>(cancellationToken);
@@ -93,7 +75,7 @@ namespace Cysharp.Threading.Tasks
 <# } else { #>
             if (asyncOperation.isDone) return <#= IsVoid(t) ? "UniTask.CompletedTask" : $"UniTask.FromResult(asyncOperation.{t.returnField})" #>;
 <# } #>
-            return new <#= ToUniTaskReturnType(t.returnType) #>(<#= t.typeName #>ConfiguredSource.Create(asyncOperation, timing, progress, cancellationToken, out var token), token);
+            return new <#= ToUniTaskReturnType(t.returnType) #>(<#= t.typeName #>ConfiguredSource.Create(asyncOperation, timing, progress, handleImmediately, cancellationToken, out var token), token);
         }
 
         public struct <#= t.typeName #>Awaiter : ICriticalNotifyCompletion
@@ -160,130 +142,6 @@ namespace Cysharp.Threading.Tasks
             }
         }
 
-        sealed class <#= t.typeName #>CallbackHandlerSource : <#= ToIUniTaskSourceReturnType(t.returnType) #>, ITaskPoolNode<<#= t.typeName #>CallbackHandlerSource>
-        {
-            static TaskPool<<#= t.typeName #>CallbackHandlerSource> pool;
-            <#= t.typeName #>CallbackHandlerSource nextNode;
-            public ref <#= t.typeName #>CallbackHandlerSource NextNode => ref nextNode;
-
-            static <#= t.typeName #>CallbackHandlerSource()
-            {
-                TaskPool.RegisterSizeGetter(typeof(<#= t.typeName #>CallbackHandlerSource), () => pool.Size);
-            }
-
-            <#= t.typeName #> asyncOperation;
-            IProgress<float> progress;
-            CancellationToken cancellationToken;
-            CancellationTokenRegistration cancellationTokenRegistration;
-
-            UniTaskCompletionSourceCore<<#= IsVoid(t) ? "AsyncUnit" : t.returnType #>> core;
-
-            <#= t.typeName #>CallbackHandlerSource()
-            {
-            }
-
-            public static <#= ToIUniTaskSourceReturnType(t.returnType) #> Create(<#= t.typeName #> asyncOperation, CancellationToken cancellationToken, out short token)
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return AutoResetUniTaskCompletionSource<#= IsVoid(t) ? "" : $"<{t.returnType}>" #>.CreateFromCanceled(cancellationToken, out token);
-                }
-
-                if (!pool.TryPop(out var result))
-                {
-                    result = new <#= t.typeName #>CallbackHandlerSource();
-                }
-
-                result.asyncOperation = asyncOperation;
-                result.cancellationToken = cancellationToken;
-
-                asyncOperation.completed += result.AsyncOperationCompletedHandler;
-
-                if (cancellationToken.CanBeCanceled)
-                {
-                    result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
-                    {
-                        var source = (<#= t.typeName #>CallbackHandlerSource)state;
-<# if(IsUnityWebRequest(t)) { #>
-                        source.asyncOperation.webRequest.Abort();
-<# } #>
-                        source.core.TrySetCanceled(source.cancellationToken);
-                    }, result);
-                }
-
-                TaskTracker.TrackActiveTask(result, 3);
-
-                token = result.core.Version;
-                return result;
-            }
-
-            public <#= t.returnType #> GetResult(short token)
-            {
-                try
-                {
-<# if (!IsVoid(t)) { #>
-                    return core.GetResult(token);
-<# } else { #>
-                    core.GetResult(token);
-<# } #>
-                }
-                finally
-                {
-                    TryReturn();
-                }
-            }
-
-<# if (!IsVoid(t)) { #>
-            void IUniTaskSource.GetResult(short token)
-            {
-                GetResult(token);
-            }
-<# } #>
-
-            public UniTaskStatus GetStatus(short token)
-            {
-                return core.GetStatus(token);
-            }
-
-            public UniTaskStatus UnsafeGetStatus()
-            {
-                return core.UnsafeGetStatus();
-            }
-
-            public void OnCompleted(Action<object> continuation, object state, short token)
-            {
-                core.OnCompleted(continuation, state, token);
-            }
-
-            bool TryReturn()
-            {
-                TaskTracker.RemoveTracking(this);
-                core.Reset();
-                asyncOperation.completed -= AsyncOperationCompletedHandler;
-                asyncOperation = default;
-                progress = default;
-                cancellationToken = default;
-                cancellationTokenRegistration.Dispose();
-                return pool.TryPush(this);
-            }
-
-            void AsyncOperationCompletedHandler(AsyncOperation _)
-            {
-<# if(IsUnityWebRequest(t)) { #>
-                if (asyncOperation.webRequest.IsError())
-                {
-                    core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
-                }
-                else
-                {
-                    core.TrySetResult(asyncOperation.webRequest);
-                }
-<# } else { #>
-                core.TrySetResult(<#= IsVoid(t) ? "AsyncUnit.Default" : $"asyncOperation.{t.returnField}" #>);
-<# } #>
-            }
-        }
-
         sealed class <#= t.typeName #>ConfiguredSource : <#= ToIUniTaskSourceReturnType(t.returnType) #>, IPlayerLoopItem, ITaskPoolNode<<#= t.typeName #>ConfiguredSource>
         {
             static TaskPool<<#= t.typeName #>ConfiguredSource> pool;
@@ -298,14 +156,18 @@ namespace Cysharp.Threading.Tasks
             <#= t.typeName #> asyncOperation;
             IProgress<float> progress;
             CancellationToken cancellationToken;
+            CancellationTokenRegistration cancellationTokenRegistration;
+            bool completed;
 
             UniTaskCompletionSourceCore<<#= IsVoid(t) ? "AsyncUnit" : t.returnType #>> core;
 
+            Action<AsyncOperation> continuationAction;
+
             <#= t.typeName #>ConfiguredSource()
             {
             }
 
-            public static <#= ToIUniTaskSourceReturnType(t.returnType) #> Create(<#= t.typeName #> asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, CancellationToken cancellationToken, out short token)
+            public static <#= ToIUniTaskSourceReturnType(t.returnType) #> Create(<#= t.typeName #> asyncOperation, PlayerLoopTiming timing, IProgress<float> progress, bool handleImmediately, CancellationToken cancellationToken, out short token)
             {
                 if (cancellationToken.IsCancellationRequested)
                 {
@@ -320,6 +182,25 @@ namespace Cysharp.Threading.Tasks
                 result.asyncOperation = asyncOperation;
                 result.progress = progress;
                 result.cancellationToken = cancellationToken;
+                result.completed = false;
+
+                if (handleImmediately)
+                {
+                    result.continuationAction = result.Continuation;
+                    asyncOperation.completed += result.continuationAction;
+
+                    if (cancellationToken.CanBeCanceled)
+                    {
+                        result.cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(state =>
+                        {
+                            var source = (<#= t.typeName #>ConfiguredSource)state;
+<# if(IsUnityWebRequest(t)) { #>
+                            source.asyncOperation.webRequest.Abort();
+<# } #>
+                            source.core.TrySetCanceled(source.cancellationToken);
+                        }, result);
+                    }
+                }
 
                 TaskTracker.TrackActiveTask(result, 3);
 
@@ -407,11 +288,44 @@ namespace Cysharp.Threading.Tasks
             {
                 TaskTracker.RemoveTracking(this);
                 core.Reset();
+                asyncOperation.completed -= continuationAction;
                 asyncOperation = default;
                 progress = default;
                 cancellationToken = default;
+                cancellationTokenRegistration.Dispose();
                 return pool.TryPush(this);
             }
+
+            void Continuation(AsyncOperation _)
+            {
+                if (completed)
+                {
+                    TryReturn();
+                }
+                else
+                {
+                    completed = true;
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        core.TrySetCanceled(cancellationToken);
+                    }
+<# if(IsUnityWebRequest(t)) { #>
+                    else if (asyncOperation.webRequest.IsError())
+                    {
+                        core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.webRequest);
+                    }
+<# } else { #>
+                    else
+                    {
+                        core.TrySetResult(<#= IsVoid(t) ? "AsyncUnit.Default" : $"asyncOperation.{t.returnField}" #>);
+                    }
+<# } #>
+                }
+            }
         }
 
         #endregion