# System.Threading

``` diff
 namespace System.Threading {
-    public struct AsyncLocalValueChangedArgs<T>
+    public readonly struct AsyncLocalValueChangedArgs<T>
     public readonly struct CancellationToken {
+        public CancellationTokenRegistration UnsafeRegister(Action<object> callback, object state);
     }
     public readonly struct CancellationTokenRegistration : IDisposable, IEquatable<CancellationTokenRegistration> {
+        public ValueTask DisposeAsync();
+        public bool Unregister();
     }
+    public interface IThreadPoolWorkItem {
+        void Execute();
+    }
     public struct SpinWait {
+        public void SpinOnce(int sleep1Threshold);
     }
     public static class ThreadPool {
+        public static bool UnsafeQueueUserWorkItem(IThreadPoolWorkItem callBack, bool preferLocal);
     }
     public sealed class Timer : MarshalByRefObject, IDisposable {
+        public ValueTask DisposeAsync();
     }
 }
```

