complete infrastructure

Assets/UniRx.Async/CompilerServices/MoveNextRunner.cs

@@ -2,11 +2,14 @@
 
 #pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
 
+using System;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using UniRx.Async.Internal;
 
 namespace UniRx.Async.CompilerServices
 {
+    // TODO: Remove it.
     internal class MoveNextRunner<TStateMachine>
         where TStateMachine : IAsyncStateMachine
     {
@@ -18,6 +21,52 @@ namespace UniRx.Async.CompilerServices
             StateMachine.MoveNext();
         }
     }
+
+    internal interface IMoveNextRunner
+    {
+        Action CallMoveNext { get; }
+        void Return();
+    }
+
+    internal class MoveNextRunner2<TStateMachine> : IMoveNextRunner, IPromisePoolItem
+        where TStateMachine : IAsyncStateMachine
+    {
+        static PromisePool<MoveNextRunner2<TStateMachine>> pool = new PromisePool<MoveNextRunner2<TStateMachine>>();
+
+        TStateMachine stateMachine;
+        internal readonly Action callMoveNext;
+
+        public Action CallMoveNext => callMoveNext;
+
+        MoveNextRunner2()
+        {
+            callMoveNext = MoveNext;
+        }
+
+        public static MoveNextRunner2<TStateMachine> Create(ref TStateMachine stateMachine)
+        {
+            var result = pool.TryRent() ?? new MoveNextRunner2<TStateMachine>();
+            result.stateMachine = stateMachine;
+            return result;
+        }
+
+        [DebuggerHidden]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        void MoveNext()
+        {
+            stateMachine.MoveNext();
+        }
+
+        public void Return()
+        {
+            pool.TryReturn(this);
+        }
+
+        void IPromisePoolItem.Reset()
+        {
+            stateMachine = default;
+        }
+    }
 }
 
 #endif