wolkykim
Asynchronous background processing?
While looking through the examples I cannot find how to not immediately send back a reply, but instead to have some form of handle stored so that it will be returned later, after the background task returned a reply. This would block the connection on HTTP.
Yes, as you mentioned, this part has to be handled in user code, you could implement a set of queuing buffer mapped to each connection. And this delayed response better to be handled in separate threads, not to block the callback since the callback is single-threaded model anything blocking the callback will block the whole process.
I understand how to not block the call, but what kind of value do I return to indicate "I'm processing this connection on a separate thread, please continue processing other connections but don't do anything to this connection until I tell you I'm done" ?
I guess you need to save the underlying *conn object in your threads and send data using the conn from the threads. I think you can also use ad_conn_set_userdata() call to store the status information if needed.