public override bool TryExecuteSync()
{
Socket socket = Socket !;
(SocketError socketError, int bytesTransferred) = SocketPal.Recv(socket.SafeHandle, MemoryBuffer);
BytesTransferred = bytesTransferred;
if (socketError == SocketError.WouldBlock)
{
return(false);
}
SocketError = socketError;
return(true);
}
public override AsyncExecutionResult TryExecute(bool triggeredByPoll, bool isCancellationRequested, bool asyncOnly, AsyncExecutionQueue?executionQueue, AsyncExecutionCallback?callback, object?state, int data, AsyncOperationResult asyncResult)
{
SocketError socketError = SocketError.SocketError;
int bytesTransferred = -1;
AsyncExecutionResult result = AsyncExecutionResult.Executing;
if (asyncResult.HasResult)
{
if (asyncResult.IsError)
{
if (asyncResult.Errno == EINTR)
{
result = AsyncExecutionResult.Executing;
}
else if (asyncResult.Errno == EAGAIN)
{
result = AsyncExecutionResult.WaitForPoll;
}
else
{
bytesTransferred = 0;
socketError = SocketPal.GetSocketErrorForErrno(asyncResult.Errno);
result = AsyncExecutionResult.Finished;
}
}
else
{
bytesTransferred = asyncResult.IntValue;
socketError = SocketError.Success;
result = AsyncExecutionResult.Finished;
}
}
if (isCancellationRequested && result != AsyncExecutionResult.Finished)
{
SocketError = SocketError.OperationAborted;
return(AsyncExecutionResult.Cancelled);
}
// When there is a pollable executionQueue, use it to poll, and then try the operation.
if (result == AsyncExecutionResult.Executing ||
(result == AsyncExecutionResult.WaitForPoll && executionQueue?.SupportsPolling == true))
{
Memory <byte> memory = MemoryBuffer;
bool isPollingReadable = memory.Length == 0; // A zero-byte read is a poll.
if (triggeredByPoll && isPollingReadable)
{
// No need to make a syscall, poll told us we're readable.
(socketError, bytesTransferred) = (SocketError.Success, 0);
result = AsyncExecutionResult.Finished;
}
else
{
Socket socket = Socket !;
// Using Linux AIO executionQueue, we can't check when there is no
// data available. Instead of return value EAGAIN, a 0-byte read returns '0'.
if (executionQueue != null &&
(!isPollingReadable || executionQueue.SupportsPolling)) // Don't use Linux AIO for 0-byte reads.
{
executionQueue.AddRead(socket.SafeHandle, memory, callback !, state, data);
result = AsyncExecutionResult.Executing;
}
else if (result == AsyncExecutionResult.Executing)
{
if (asyncOnly)
{
result = AsyncExecutionResult.WaitForPoll;
}
else
{
(socketError, bytesTransferred) = SocketPal.Recv(socket.SafeHandle, memory);
result = socketError == SocketError.WouldBlock ? AsyncExecutionResult.WaitForPoll : AsyncExecutionResult.Finished;
}
}
}
}
if (result == AsyncExecutionResult.Finished)
{
Debug.Assert(bytesTransferred != -1);
BytesTransferred = bytesTransferred;
SocketError = socketError;
}
return(result);
}
