[zeromq-dev] zeromq-dev Digest, Vol 19, Issue 7

[Alexander Petry]

Hi!

> Date: Fri, 10 Jul 2009 22:10:44 +0200
> From: Ferenc Szalai <szferi at wsbricks.com>
> Subject: [zeromq-dev] inter thread shared q messaging
> To: zeromq-dev at mail.imatix.com
> Message-ID: <4A57A044.3090702 at wsbricks.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Hi
> 
> I included source which try to demonstrate what I would like to achieve.
> The main idea is to broadcast message from writer thread to all reader 
> thread. Unfortunatelly this is not a case with the attached source, only 
> one reader thread gets the message.
> 
> Is it really required to put an intermediate "broker thread" to the 
> picture to resolve this issue or there is other way?

As I understood it, you should make the exchange global and each  reader
binds a local queue to that exchange and receives messages through  that
queue.   I  guess  the  problem   with   your   code   is,   that   each
reader "overwrites" the global information for the "PROCESS_Q". Just an
idea.

alex

PS: sorry for the ugly reply to the digest.

> 
> #include <zmq.hpp>
> #include <boost/shared_ptr.hpp>
> #include <boost/thread.hpp>
> 
> zmq::dispatcher_t *dispatcher = new zmq::dispatcher_t(3);
> zmq::locator_t *locator = new zmq::locator_t();
> 
> void th_read()
> {
>      zmq::api_thread_t *api = zmq::api_thread_t::create(dispatcher, 
> locator);
>      api->create_queue("PROCESS_Q", zmq::scope_process);
> 
>      zmq::message_t in_msg;
>      api->receive(&in_msg);
>      std::cout << (unsigned char *)in_msg.data() << std::endl;
> }
> 
> void th_write()
> {
>      zmq::api_thread_t *api = zmq::api_thread_t::create(dispatcher, 
> locator);
>      int eid = api->create_exchange("LOCAL_X");
>      api->bind("LOCAL_X", "PROCESS_Q", NULL, NULL);
> 
>      sleep(1);
>      std::string s("hello");
>      zmq::message_t msg(s.size() + 1);
>      memcpy(msg.data(), s.c_str(), s.size() + 1);
>      api->send(eid, msg);
> }
> 
> int
> main()
> {
>      boost::shared_ptr<boost::thread> reader1(new boost::thread(&th_read));
>      boost::shared_ptr<boost::thread> reader2(new boost::thread(&th_read));
>      boost::shared_ptr<boost::thread> writer(new boost::thread(&th_write));
>      reader1->join();
>      reader2->join();
>      writer->join();
> 
>      return 0;
> }
> 
> --
> Regards
> Ferenc
> 
> 
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> End of zeromq-dev Digest, Vol 19, Issue 7
> *****************************************