1 files changed, 52 insertions, 0 deletions
diff --git a/src/mscorlib/src/System/Threading/ClrThreadPoolBoundHandleOverlapped.cs b/src/mscorlib/src/System/Threading/ClrThreadPoolBoundHandleOverlapped.cs
new file mode 100644
index 0000000000..1aea2a294b
--- /dev/null
+++ b/src/mscorlib/src/System/Threading/ClrThreadPoolBoundHandleOverlapped.cs
@@ -0,0 +1,52 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace System.Threading
+{
+    /// <summary>
+    /// Overlapped subclass adding data needed by ThreadPoolBoundHandle.
+    /// </summary>
+    internal sealed class ThreadPoolBoundHandleOverlapped : Overlapped
+    {
+        private static readonly unsafe IOCompletionCallback s_completionCallback = CompletionCallback;
+
+        private readonly IOCompletionCallback _userCallback;
+        internal readonly object _userState;
+        internal PreAllocatedOverlapped _preAllocated;
+        internal unsafe NativeOverlapped* _nativeOverlapped;
+        internal ThreadPoolBoundHandle _boundHandle;
+        internal bool _completed;
+
+        public unsafe ThreadPoolBoundHandleOverlapped(IOCompletionCallback callback, object state, object pinData, PreAllocatedOverlapped preAllocated)
+        {
+            _userCallback = callback;
+            _userState = state;
+            _preAllocated = preAllocated;
+
+            _nativeOverlapped = Pack(s_completionCallback, pinData);
+            _nativeOverlapped->OffsetLow = 0;        // CLR reuses NativeOverlapped instances and does not reset these
+            _nativeOverlapped->OffsetHigh = 0;
+        }
+
+        private unsafe static void CompletionCallback(uint errorCode, uint numBytes, NativeOverlapped* nativeOverlapped)
+        {
+            ThreadPoolBoundHandleOverlapped overlapped = (ThreadPoolBoundHandleOverlapped)Overlapped.Unpack(nativeOverlapped);
+
+            //
+            // The Win32 thread pool implementation of ThreadPoolBoundHandle does not permit reuse of NativeOverlapped
+            // pointers without freeing them and allocating new a new one.  We need to ensure that code using the CLR
+            // ThreadPool implementation follows those rules.
+            //
+            if (overlapped._completed)
+                throw new InvalidOperationException(SR.InvalidOperation_NativeOverlappedReused);
+
+            overlapped._completed = true;
+
+            if (overlapped._boundHandle == null)
+                throw new InvalidOperationException(SR.Argument_NativeOverlappedAlreadyFree);
+
+            overlapped._userCallback(errorCode, numBytes, nativeOverlapped);
+        }
+    }
+}