internal static extern bool GetQueuedCompletionStatus( SafeIoCompletionPortHandle CompletionPort, out uint lpNumberOfBytes, out IntPtr lpCompletionKey, out IntPtr lpOverlapped, int dwMilliseconds);
internal static extern bool PostQueuedCompletionStatus( SafeIoCompletionPortHandle CompletionPort, uint dwNumberOfBytesTransferred, IntPtr dwCompletionKey, IntPtr lpOverlapped);