This is yet another request for your insights... I will have a process that may be receiving incoming data on multiple sockets (probably a couple of Upstream sockets, at least one Sub socket). I see two designs to handle this, each with different implications on fairness; by "fairness" I am thinking about processing incoming messages from all sockets in a way that none of them waits "too long" to be processed.
1. Have many threads; each thread waits on a zmq_recv() call and, upon receiving a message, processes it right away and goes back to calling zmq_recv(). Of course this means I would have to use mutual exclusion for processing the messages (supposing this processing will need to touch shared structures). In this scenario, I would be trusting the thread scheduling mechanism (however goo or bad) to ensure fairness. 2. Have a single thread doing a zmq_poll() on all sockets; upon being signaled, process the messages on all signaled sockets. But in which order? What if socket 1 has 100 pending messages and socket 2 has 3 pending messages? Which ones do I process first, and how do I know the pending queue length for each socket? Related question: if a socket receives 10 messages, causing zmq_poll() to wake up, and I only read 2 of those messages, will zmq_poll() wake up right away if I call it again, or do I have to process all 10 messages before counting on this? (I believe this is called "edge-triggering" vs. "level-triggering"). 3. I could also have a hybrid: many threads, as in #1, but they simply put all incoming messages on a single queue. Then have one thread (or more) fetching elements off this queue and processing them. It adds more latency and it forces me to use mutual exclusion for pushing elements on the queue tail and reading them off the queue head, but looks "saner" to me and I might even use the queue to handle retries. Perhaps I am barking up the wrong tree here; would appreciate hearing any advise anyone might have. Thanks in advance. -- Gonzalo Diethelm ----------------------------------------- Declaración de confidencialidad: Este Mensaje esta destinado para el uso de la o las personas o entidades a quien ha sido dirigido y puede contener información reservada y confidencial que no puede ser divulgada, difundida, ni aprovechada en forma alguna. El uso no autorizado de la información contenida en este correo podrá ser sancionado de conformidad con la ley chilena. Si usted ha recibido este correo electrónico por error, le pedimos eliminarlo junto con los archivos adjuntos y avisar inmediatamente al remitente, respondiendo este mensaje. "Before printing this e-mail think if is really necesary". Disclosure: This Message is to be used by the individual, individuals or entities that it is addressed to and may include private and confidential information that may not be disclosed, made public nor used in any way at all. Unauthorized use of the information in this electronic mail message may be subject to the penalties set forth by Chilean law. If you have received this electronic mail message in error, we ask you to destroy the message and its attached file(s) and to immediately notify the sender by answering this message. _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
