public unsafe void Start(IntPtr completionPort)
{
while (true)
{
uint bytesRead;
uint completionKey;
NativeOverlapped *nativeOverlapped;
ThreadLogger.Log("About to get queued completion status on {0}", completionPort);
var result = Interop.GetQueuedCompletionStatus(
completionPort,
out bytesRead,
out completionKey,
&nativeOverlapped,
uint.MaxValue);
var overlapped = Overlapped.Unpack(nativeOverlapped);
if (result)
{
var asyncResult = ((FileReadAsyncResult)overlapped.AsyncResult);
asyncResult.ReadCallback(bytesRead, asyncResult.Buffer);
}
else
{
ThreadLogger.Log(Interop.GetLastError().ToString());
}
Overlapped.Free(nativeOverlapped);
}
}
static unsafe void Main(string[] args)
{
// create completion port
var completionPortHandle = Interop.CreateIoCompletionPort(new IntPtr(-1), IntPtr.Zero, 0, 0);
ThreadLogger.Log("Completion port handle: {0}", completionPortHandle);
var completionPortThread = new Thread(() => new IOCompletionWorker().Start(completionPortHandle))
{
IsBackground = true
};
completionPortThread.Start();
const uint Flags = 128 | (uint)1 << 30;
var fileHandle = Interop.CreateFile("test.txt", (uint)1 << 31, 0, IntPtr.Zero, 3,
/*FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED */ Flags,
IntPtr.Zero);
ThreadLogger.Log("File handle: {0}", fileHandle);
Interop.CreateIoCompletionPort(
fileHandle,
completionPortHandle,
(uint)fileHandle.ToInt64(),
0);
ThreadLogger.Log("Associated file handle with completion port");
var readBuffer = new byte[1024];
uint bytesRead;
var overlapped = new Overlapped
{
AsyncResult = new FileReadAsyncResult()
{
ReadCallback = (bytesCount, buffer) =>
{
var contentRead = Encoding.UTF8.GetString(buffer, 0, (int)bytesCount);
ThreadLogger.Log(contentRead);
},
Buffer = readBuffer
}
};
NativeOverlapped *nativeOverlapped = overlapped.UnsafePack(null, readBuffer);
ThreadLogger.Log("Before read in main thread");
Interop.ReadFile(fileHandle, readBuffer, (uint)readBuffer.Length, out bytesRead, nativeOverlapped);
ThreadLogger.Log("After read in main thread");
Console.ReadLine();
}
public static void Log(string messageFormat, params object[] placeholders)
{
ThreadLogger.Log(string.Format(messageFormat, placeholders));
}