use PooledDelegate to avoid convert Action to Action<AsyncOperation> allocation

src/UniTask.NetCore/NetCore/UniTask.Yield.cs

@@ -59,7 +59,7 @@ namespace Cysharp.Threading.Tasks
 
 #if NETCOREAPP3_1
 
-            public sealed class ThreadPoolWorkItem : IThreadPoolWorkItem
+            sealed class ThreadPoolWorkItem : IThreadPoolWorkItem
             {
                 static readonly ConcurrentQueue<ThreadPoolWorkItem> pool = new ConcurrentQueue<ThreadPoolWorkItem>();
 

src/UniTask/Assets/Plugins/UniTask/Runtime/External/AddressableAsyncExtensions.cs

@@ -72,7 +72,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperationHandle>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperationHandle>.Create(continuation);
                 handle.Completed += continuationAction;
             }
         }
@@ -249,7 +249,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperationHandle>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperationHandle>.Create(continuation);
                 handle.CompletedTypeless += continuationAction;
             }
         }

src/UniTask/Assets/Plugins/UniTask/Runtime/External/DoTweenAsyncExtensions.cs

@@ -5,6 +5,7 @@
 using Cysharp.Threading.Tasks.Internal;
 using DG.Tweening;
 using System;
+using System.Collections.Concurrent;
 using System.Runtime.CompilerServices;
 using System.Threading;
 
@@ -77,9 +78,8 @@ namespace Cysharp.Threading.Tasks
 
             public void UnsafeOnCompleted(System.Action continuation)
             {
-                // convert Action -> TweenCallback allocation.
                 // onKill is called after OnCompleted, both Complete(false/true) and Kill(false/true).
-                tween.onKill = new TweenCallback(continuation);
+                tween.onKill = PooledTweenCallback.Create(continuation);
             }
         }
 
@@ -89,6 +89,8 @@ namespace Cysharp.Threading.Tasks
             static readonly Action<object> CancellationCallbackDelegate = CancellationCallback;
             static readonly TweenCallback EmptyTweenCallback = () => { };
 
+            readonly TweenCallback onKillDelegate;
+
             Tween tween;
             TweenCancelBehaviour cancelBehaviour;
             CancellationToken cancellationToken;
@@ -99,7 +101,7 @@ namespace Cysharp.Threading.Tasks
 
             TweenConfiguredSource()
             {
-
+                onKillDelegate = OnKill;
             }
 
             public static IUniTaskSource Create(Tween tween, TweenCancelBehaviour cancelBehaviour, CancellationToken cancellationToken, out short token)
@@ -130,8 +132,7 @@ namespace Cysharp.Threading.Tasks
                     cancellationTokenRegistration = cancellationToken.RegisterWithoutCaptureExecutionContext(CancellationCallbackDelegate, this);
                 }
 
-                // allocate delegate.
+                tween.OnKill(onKillDelegate);
-                tween.OnKill(new TweenCallback(OnKill));
             }
 
             void OnKill()
@@ -234,6 +235,45 @@ namespace Cysharp.Threading.Tasks
             }
         }
     }
+
+    sealed class PooledTweenCallback
+    {
+        static readonly ConcurrentQueue<PooledTweenCallback> pool = new ConcurrentQueue<PooledTweenCallback>();
+
+        readonly TweenCallback runDelegate;
+
+        Action continuation;
+
+
+        PooledTweenCallback()
+        {
+            runDelegate = Run;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static TweenCallback Create(Action continuation)
+        {
+            if (!pool.TryDequeue(out var item))
+            {
+                item = new PooledTweenCallback();
+            }
+
+            item.continuation = continuation;
+            return item.runDelegate;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void Run()
+        {
+            var call = continuation;
+            continuation = null;
+            if (call != null)
+            {
+                pool.Enqueue(this);
+                call.Invoke();
+            }
+        }
+    }
 }
 
 #endif

src/UniTask/Assets/Plugins/UniTask/Runtime/Internal/PooledDelegate.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
+
+namespace Cysharp.Threading.Tasks.Internal
+{
+    internal class PooledDelegate<T>
+    {
+        static readonly ConcurrentQueue<PooledDelegate<T>> pool = new ConcurrentQueue<PooledDelegate<T>>();
+
+        readonly Action<T> runDelegate;
+
+        Action continuation;
+
+
+        PooledDelegate()
+        {
+            runDelegate = Run;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Action<T> Create(Action continuation)
+        {
+            if (!pool.TryDequeue(out var item))
+            {
+                item = new PooledDelegate<T>();
+            }
+
+            item.continuation = continuation;
+            return item.runDelegate;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void Run(T _)
+        {
+            var call = continuation;
+            continuation = null;
+            if (call != null)
+            {
+                pool.Enqueue(this);
+                call.Invoke();
+            }
+        }
+    }
+}

src/UniTask/Assets/Plugins/UniTask/Runtime/Internal/PooledDelegate.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 8932579438742fa40b010edd412dbfba
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Plugins/UniTask/Runtime/UniTaskVoid.cs

@@ -14,36 +14,6 @@ namespace Cysharp.Threading.Tasks
         public void Forget()
         {
         }
-
-        //        [DebuggerHidden]
-        //        public Awaiter GetAwaiter()
-        //        {
-        //            return new Awaiter();
-        //        }
-
-        //        public struct Awaiter : ICriticalNotifyCompletion
-        //        {
-        //            [DebuggerHidden]
-        //            public bool IsCompleted => true;
-
-        //            [DebuggerHidden]
-        //            public void GetResult()
-        //            {
-        //#if UNITY_2018_3_OR_NEWER
-        //                UnityEngine.Debug.LogWarning("UniTaskVoid can't await, always fire-and-forget. use Forget instead of await.");
-        //#endif
-        //            }
-
-        //            [DebuggerHidden]
-        //            public void OnCompleted(Action continuation)
-        //            {
-        //            }
-
-        //            [DebuggerHidden]
-        //            public void UnsafeOnCompleted(Action continuation)
-        //            {
-        //            }
-        //        }
     }
 }
 

src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs

@@ -70,7 +70,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperation>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperation>.Create(continuation);
                 asyncOperation.completed += continuationAction;
             }
         }
@@ -242,7 +242,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperation>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperation>.Create(continuation);
                 asyncOperation.completed += continuationAction;
             }
         }
@@ -419,7 +419,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperation>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperation>.Create(continuation);
                 asyncOperation.completed += continuationAction;
             }
         }
@@ -596,7 +596,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperation>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperation>.Create(continuation);
                 asyncOperation.completed += continuationAction;
             }
         }
@@ -774,7 +774,7 @@ namespace Cysharp.Threading.Tasks
             public void UnsafeOnCompleted(Action continuation)
             {
                 Error.ThrowWhenContinuationIsAlreadyRegistered(continuationAction);
-                continuationAction = continuation.AsFuncOfT<AsyncOperation>(); // allocate delegate.
+                continuationAction = PooledDelegate<AsyncOperation>.Create(continuation);
                 asyncOperation.completed += continuationAction;
             }
         }

src/UniTask/Assets/Scenes/SandboxMain.cs

@@ -13,7 +13,6 @@ using UnityEngine;
 using UnityEngine.Networking;
 using UnityEngine.UI;
 
-
 // using DG.Tweening;
 
 public struct MyJob : IJob
@@ -259,11 +258,15 @@ public class SandboxMain : MonoBehaviour
     {
         try
         {
-            var cts = new CancellationTokenSource();
+            //var cts = new CancellationTokenSource();
-            var r = UniAsync("https://bing.com/", cts.Token);
+            //var r = UniAsync("https://bing.com/", cts.Token);
-            cts.Cancel();
+            //cts.Cancel();
-            await r;
+            //await r;
-            Debug.Log("UNIASYNC");
+            _ = await UnityWebRequest.Get("https://bing.com/").SendWebRequest();
+            Debug.Log("UNIASYNC1 ");
+
+            _ = await UnityWebRequest.Get("https://bing.com/").SendWebRequest();
+            Debug.Log("UNIASYNC2");
         }
         catch
         {
@@ -291,7 +294,7 @@ public class SandboxMain : MonoBehaviour
     }
 
 
-    void Start()
+    async UniTaskVoid Start()
     {
         //UniTaskAsyncEnumerable.EveryValueChanged(mcc, x => x.MyProperty)
         //    .Do(_ => { }, () => Debug.Log("COMPLETED"))
@@ -301,15 +304,23 @@ public class SandboxMain : MonoBehaviour
         //    })
         //    .Forget();
 
-        _ = Test1();
+        //_ = Test1();
         Test2().Forget();
-        StartCoroutine(Test3("https://bing.com/"));
+        //StartCoroutine(Test3("https://bing.com/"));
 
 
         // DG.Tweening.Core.TweenerCore<int>
-        //okButton.GetComponent<RectTransform>().DOMoveX(10.2f, 30);
+        //Debug.Log("GO MOVEX");
+        //await okButton.GetComponent<RectTransform>().DOMoveX(-10.2f, 3).WithCancellation(CancellationToken.None);
+        //Debug.Log("END MOVEX");
 
 
+        //Debug.Log("AGAIN MOVE");
+        //await okButton.GetComponent<RectTransform>().DOMoveY(10.2f, 3).WithCancellation(CancellationToken.None);
+        //Debug.Log("AGAIN END MOVE");
+
+
+        await UniTask.Yield();
         // DOTween.To(
 
         var cts = new CancellationTokenSource();