private IEnumerator <bool> GetReceiveEnumerator(ParameterlessDelegate callback)
{
_receiveArgs.UserToken = callback;
try
{
while (true)
{
if (_error != null)
{
yield break;
}
// note - it seems this is necessary because of a bug in the SendAsync function
// see - http://social.msdn.microsoft.com/Forums/en-IE/ncl/thread/40fe397c-b1da-428e-a355-ee5a6b0b4d2c
Thread.MemoryBarrier();
LogDebugStep("Receiving...");
yield return(!_socket.ReceiveAsync(_receiveArgs));
LogDebugStep("Receive Complete.");
if (!ValidateCompletedEvent(_receiveArgs, SocketAsyncOperation.Receive))
{
yield break;
}
if (_receiveArgs.BytesTransferred == 0)
{
SetError(SocketError.ConnectionReset);
yield break;
}
if (_operationType != OperationType.RoundTrip)
{
SetError(new InvalidOperationException("Received data when no round trip operation was pending."));
yield break;
}
int position = _receiveArgs.Offset;
int count = _receiveArgs.BytesTransferred;
if (!_responseHeader.IsComplete)
{
position += _responseHeader.Read(_receiveArgs.Buffer, position, count - position);
if (!_responseHeader.IsComplete || count == position)
{
if (_log.IsDebugEnabled)
{
LogDebugStep(string.Format("Received partial header {0:###,##0} bytes", count - position));
}
continue;
}
}
if (_responseData == null)
{
_responseData = AsyncSocketClient.MemoryPool.Borrow();
}
int countAvailable = count - position;
int countNeeded = _responseHeader.MessageDataLength - (int)_responseData.Item.Length;
if (countNeeded <= countAvailable)
{
_responseData.Item.Write(_receiveArgs.Buffer, position, countNeeded);
_responseData.Item.Seek(0, SeekOrigin.Begin);
if (_responseHeader.MessageLength == ServerMessage.EmptyReplyMessageLength &&
ServerMessage.IsEmptyMessage(_responseData.Item.GetBuffer(), (int)_responseData.Item.Position, _responseHeader.MessageLength))
{
_responseData.Dispose();
_responseData = null;
}
_responseReceived = true;
}
else
{
_responseData.Item.Write(_receiveArgs.Buffer, position, countAvailable);
}
if (_log.IsDebugEnabled)
{
LogDebugStep(countAvailable + " of " + countNeeded + " bytes received. " + (countNeeded - countAvailable) + " bytes remaining. Complete=" + IsOperationComplete);
}
}
}
finally
{
LogDebugStep("Receive Loop Ended.");
}
}
