private void ActivateNewRequest(SafeCurlMultiHandle multiHandle, EasyRequest easy)
{
Debug.Assert(easy != null, "We should never get a null request");
Debug.Assert(easy._associatedMultiAgent == null, "New requests should not be associated with an agent yet");
// If cancellation has been requested, complete the request proactively
if (easy._cancellationToken.IsCancellationRequested)
{
easy.FailRequest(new OperationCanceledException(easy._cancellationToken));
easy.Cleanup(); // no active processing remains, so cleanup
return;
}
// Otherwise, configure it. Most of the configuration was already done when the EasyRequest
// was created, but there's additional configuration we need to do specific to this
// multi agent, specifically telling the easy request about its own GCHandle and setting
// up callbacks for data processing. Once it's configured, add it to the multi handle.
GCHandle gcHandle = GCHandle.Alloc(easy);
IntPtr gcHandlePtr = GCHandle.ToIntPtr(gcHandle);
try
{
easy._associatedMultiAgent = this;
easy.SetCurlOption(CURLoption.CURLOPT_PRIVATE, gcHandlePtr);
easy.SetCurlCallbacks(gcHandlePtr, s_receiveHeadersCallback, s_sendCallback, s_seekCallback, s_receiveBodyCallback);
ThrowIfCURLMError(Interop.Http.MultiAddHandle(multiHandle, easy._easyHandle));
}
catch (Exception exc)
{
gcHandle.Free();
easy.FailRequest(exc);
easy.Cleanup(); // no active processing remains, so cleanup
return;
}
// And if cancellation can be requested, hook up a cancellation callback.
// This callback will put the easy request back into the queue, which will
// ensure that a wake-up request has been issued. When we pull
// the easy request out of the request queue, we'll see that it's already
// associated with this agent, meaning that it's a cancellation request,
// and we'll deal with it appropriately.
var cancellationReg = default(CancellationTokenRegistration);
if (easy._cancellationToken.CanBeCanceled)
{
cancellationReg = easy._cancellationToken.Register(s =>
{
var state = (Tuple<MultiAgent, EasyRequest>)s;
state.Item1.Queue(new IncomingRequest { Easy = state.Item2, Type = IncomingRequestType.Cancel });
}, Tuple.Create<MultiAgent, EasyRequest>(this, easy));
}
// Finally, add it to our map.
_activeOperations.Add(
gcHandlePtr,
new ActiveRequest { Easy = easy, CancellationRegistration = cancellationReg });
}