From cc58bb0e73595551d1af71fd139b1783265c04cf Mon Sep 17 00:00:00 2001
From: vsadov <8218165+VSadov@users.noreply.github.com>
Date: Fri, 17 Oct 2025 17:43:23 -0700
Subject: [PATCH 1/3] Enable async feature/tests

---
 src/coreclr/inc/clrconfigvalues.h       | 2 +-
 src/tests/async/Directory.Build.targets | 5 -----
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/src/coreclr/inc/clrconfigvalues.h b/src/coreclr/inc/clrconfigvalues.h
index 3a1b3dc5fbe19c..754b462be0e7d2 100644
--- a/src/coreclr/inc/clrconfigvalues.h
+++ b/src/coreclr/inc/clrconfigvalues.h
@@ -714,7 +714,7 @@ RETAIL_CONFIG_DWORD_INFO(EXTERNAL_EnableRiscV64Zbb,             W("EnableRiscV64
 #endif
 
 // Runtime-async
-RETAIL_CONFIG_DWORD_INFO(UNSUPPORTED_RuntimeAsync, W("RuntimeAsync"), 0, "Enables runtime async method support")
+RETAIL_CONFIG_DWORD_INFO(UNSUPPORTED_RuntimeAsync, W("RuntimeAsync"), 1, "Enables runtime async method support")
 
 ///
 /// Uncategorized
diff --git a/src/tests/async/Directory.Build.targets b/src/tests/async/Directory.Build.targets
index 5a4d413a9e1f62..61a1b2822ed114 100644
--- a/src/tests/async/Directory.Build.targets
+++ b/src/tests/async/Directory.Build.targets
@@ -4,10 +4,5 @@
     <DisableProjectBuild Condition="'$(RuntimeFlavor)' == 'mono' or '$(TestBuildMode)' == 'nativeaot' or '$(TargetArchitecture)' == 'wasm'">true</DisableProjectBuild>
   </PropertyGroup>
 
-  <PropertyGroup>
-    <!-- runtime async testing in main repo NYI -->
-    <DisableProjectBuild>true</DisableProjectBuild>
-  </PropertyGroup>
-
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets, $(MSBuildThisFileDirectory)..))" />
 </Project>

From fe10fa838bf4dca1fc635852bbf750f44c77e006 Mon Sep 17 00:00:00 2001
From: vsadov <8218165+VSadov@users.noreply.github.com>
Date: Fri, 7 Nov 2025 14:39:28 -0800
Subject: [PATCH 2/3] Do not hold to the last used Continuation in the runtime
 async tasks.

---
 .../CompilerServices/AsyncHelpers.CoreCLR.cs  | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.CoreCLR.cs b/src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.CoreCLR.cs
index 19ea178f6bf1f9..d7eead54192d55 100644
--- a/src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.CoreCLR.cs
+++ b/src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncHelpers.CoreCLR.cs
@@ -238,7 +238,7 @@ private static void TransparentAwait(object o)
         private interface IRuntimeAsyncTaskOps<T>
         {
             static abstract Action GetContinuationAction(T task);
-            static abstract Continuation GetContinuationState(T task);
+            static abstract Continuation MoveContinuationState(T task);
             static abstract void SetContinuationState(T task, Continuation value);
             static abstract bool SetCompleted(T task);
             static abstract void PostToSyncContext(T task, SynchronizationContext syncCtx);
@@ -297,9 +297,16 @@ void ITaskCompletionAction.Invoke(Task completingTask)
             private struct Ops : IRuntimeAsyncTaskOps<RuntimeAsyncTask<T>>
             {
                 public static Action GetContinuationAction(RuntimeAsyncTask<T> task) => (Action)task.m_action!;
-                public static Continuation GetContinuationState(RuntimeAsyncTask<T> task) => (Continuation)task.m_stateObject!;
+                public static Continuation MoveContinuationState(RuntimeAsyncTask<T> task)
+                {
+                    Continuation continuation = (Continuation)task.m_stateObject!;
+                    task.m_stateObject = null;
+                    return continuation;
+                }
+
                 public static void SetContinuationState(RuntimeAsyncTask<T> task, Continuation value)
                 {
+                    Debug.Assert(task.m_stateObject == null);
                     task.m_stateObject = value;
                 }
 
@@ -373,9 +380,16 @@ void ITaskCompletionAction.Invoke(Task completingTask)
             private struct Ops : IRuntimeAsyncTaskOps<RuntimeAsyncTask>
             {
                 public static Action GetContinuationAction(RuntimeAsyncTask task) => (Action)task.m_action!;
-                public static Continuation GetContinuationState(RuntimeAsyncTask task) => (Continuation)task.m_stateObject!;
+                public static Continuation MoveContinuationState(RuntimeAsyncTask task)
+                {
+                    Continuation continuation = (Continuation)task.m_stateObject!;
+                    task.m_stateObject = null;
+                    return continuation;
+                }
+
                 public static void SetContinuationState(RuntimeAsyncTask task, Continuation value)
                 {
+                    Debug.Assert(task.m_stateObject == null);
                     task.m_stateObject = value;
                 }
 
@@ -429,7 +443,7 @@ public static unsafe void DispatchContinuations<T, TOps>(T task) where T : Task,
 
                 DispatcherInfo dispatcherInfo;
                 dispatcherInfo.Next = t_dispatcherInfo;
-                dispatcherInfo.NextContinuation = TOps.GetContinuationState(task);
+                dispatcherInfo.NextContinuation = TOps.MoveContinuationState(task);
                 t_dispatcherInfo = &dispatcherInfo;
 
                 while (true)

From f2bfa918100571a3d9ef420499bb5b7e6205820f Mon Sep 17 00:00:00 2001
From: vsadov <8218165+VSadov@users.noreply.github.com>
Date: Sat, 8 Nov 2025 11:49:05 -0800
Subject: [PATCH 3/3] Revert "Enable async feature/tests"

This reverts commit cc58bb0e73595551d1af71fd139b1783265c04cf.
---
 src/coreclr/inc/clrconfigvalues.h       | 2 +-
 src/tests/async/Directory.Build.targets | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/inc/clrconfigvalues.h b/src/coreclr/inc/clrconfigvalues.h
index 754b462be0e7d2..3a1b3dc5fbe19c 100644
--- a/src/coreclr/inc/clrconfigvalues.h
+++ b/src/coreclr/inc/clrconfigvalues.h
@@ -714,7 +714,7 @@ RETAIL_CONFIG_DWORD_INFO(EXTERNAL_EnableRiscV64Zbb,             W("EnableRiscV64
 #endif
 
 // Runtime-async
-RETAIL_CONFIG_DWORD_INFO(UNSUPPORTED_RuntimeAsync, W("RuntimeAsync"), 1, "Enables runtime async method support")
+RETAIL_CONFIG_DWORD_INFO(UNSUPPORTED_RuntimeAsync, W("RuntimeAsync"), 0, "Enables runtime async method support")
 
 ///
 /// Uncategorized
diff --git a/src/tests/async/Directory.Build.targets b/src/tests/async/Directory.Build.targets
index 61a1b2822ed114..5a4d413a9e1f62 100644
--- a/src/tests/async/Directory.Build.targets
+++ b/src/tests/async/Directory.Build.targets
@@ -4,5 +4,10 @@
     <DisableProjectBuild Condition="'$(RuntimeFlavor)' == 'mono' or '$(TestBuildMode)' == 'nativeaot' or '$(TargetArchitecture)' == 'wasm'">true</DisableProjectBuild>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <!-- runtime async testing in main repo NYI -->
+    <DisableProjectBuild>true</DisableProjectBuild>
+  </PropertyGroup>
+
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets, $(MSBuildThisFileDirectory)..))" />
 </Project>