public void CancelPendingIO()
{
lock (m_outstandingRequests.SyncRoot)
{
for (int i = m_outstandingRequests.Count - 1; i >= 0; i--)
{
AsyncFileStream_AsyncResult asfar = (AsyncFileStream_AsyncResult)m_outstandingRequests[i];
asfar.SignalCompleted();
}
m_outstandingRequests.Clear();
}
}
public override void EndWrite(IAsyncResult asyncResult)
{
AsyncFileStream_AsyncResult afsar = CheckParameterForEnd(asyncResult, true);
afsar.WaitCompleted();
m_outstandingRequests.Remove(afsar);
// Now check for any error during the write.
if (afsar.m_errorCode != 0)
{
throw new IOException("Async Write failed", afsar.m_errorCode);
}
}
public override int EndRead(IAsyncResult asyncResult)
{
AsyncFileStream_AsyncResult afsar = CheckParameterForEnd(asyncResult, false);
afsar.WaitCompleted();
m_outstandingRequests.Remove(afsar);
// Now check for any error during the read.
if (afsar.m_errorCode != 0)
{
throw new IOException("Async Read failed", afsar.m_errorCode);
}
return(afsar.m_numBytes);
}
private AsyncFileStream_AsyncResult CheckParameterForEnd(IAsyncResult asyncResult, bool isWrite)
{
if (asyncResult == null)
{
throw new ArgumentNullException("asyncResult");
}
AsyncFileStream_AsyncResult afsar = asyncResult as AsyncFileStream_AsyncResult;
if (afsar == null || afsar.m_isWrite != isWrite)
{
throw new ArgumentException("asyncResult");
}
if (afsar.m_EndXxxCalled)
{
throw new InvalidOperationException("EndRead called twice");
}
afsar.m_EndXxxCalled = true;
return(afsar);
}
// this callback is called by a free thread in the threadpool when the IO operation completes.
unsafe private static void DoneCallback(uint errorCode, uint numBytes, NativeOverlapped *pOverlapped)
{
if (errorCode == Native.ERROR_OPERATION_ABORTED)
{
numBytes = 0;
errorCode = 0;
}
// Unpack overlapped
Overlapped overlapped = Overlapped.Unpack(pOverlapped);
// Free the overlapped struct in EndRead/EndWrite.
// Extract async result from overlapped
AsyncFileStream_AsyncResult asyncResult = (AsyncFileStream_AsyncResult)overlapped.AsyncResult;
asyncResult.m_numBytes = (int)numBytes;
asyncResult.m_errorCode = (int)errorCode;
asyncResult.SignalCompleted();
}
private unsafe IAsyncResult BeginWriteCore(byte[] array, int offset, int count, AsyncCallback userCallback, Object stateObject)
{
CheckParametersForBegin(array, offset, count);
AsyncFileStream_AsyncResult asyncResult = new AsyncFileStream_AsyncResult(userCallback, stateObject, true);
if (count == 0)
{
asyncResult.SignalCompleted();
}
else
{
// Keep the array in one location in memory until the OS writes the
// relevant data into the array. Free GCHandle later.
asyncResult.PinBuffer(array);
fixed(byte *p = array)
{
int numBytesWritten = 0;
bool res;
res = Native.WriteFile(m_handle.DangerousGetHandle(), p + offset, count, out numBytesWritten, asyncResult.OverlappedPtr);
if (res == false)
{
if (HandleErrorSituation("BeginWrite", true))
{
asyncResult.SignalCompleted();
}
else
{
m_outstandingRequests.Add(asyncResult);
}
}
}
}
return(asyncResult);
}
private unsafe IAsyncResult BeginReadCore(byte[] array, int offset, int count, AsyncCallback userCallback, Object stateObject)
{
CheckParametersForBegin(array, offset, count);
AsyncFileStream_AsyncResult asyncResult = new AsyncFileStream_AsyncResult(userCallback, stateObject, false);
if (count == 0)
{
asyncResult.SignalCompleted();
}
else
{
// Keep the array in one location in memory until the OS writes the
// relevant data into the array. Free GCHandle later.
asyncResult.PinBuffer(array);
fixed (byte* p = array)
{
int numBytesRead = 0;
bool res;
res = Native.ReadFile(m_handle.DangerousGetHandle(), p + offset, count, out numBytesRead, asyncResult.OverlappedPtr);
if (res == false)
{
if (HandleErrorSituation("BeginRead", false))
{
asyncResult.SignalCompleted();
}
else
{
m_outstandingRequests.Add(asyncResult);
}
}
}
}
return asyncResult;
}
