2010-02-10 16:18:46 +01:00
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zmq_socket(3)
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=============
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NAME
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----
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zmq_socket - creates 0MQ socket
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SYNOPSIS
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--------
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'void *zmq_socket (void *context, int type);'
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DESCRIPTION
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-----------
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Open a socket within the specified 'context'. To create a context, use
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'zmq_init' function. 'type' argument can be one of the values defined below.
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Note that each socket is owned by exactly one thread (the one that it was
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created from) and should not be used from any other thread.
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*ZMQ_P2P*::
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Socket to communicate with a single peer. Allows for only a single connect
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or a single bind. There's no message routing or message filtering involved.
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+
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Compatible peer sockets: ZMQ_P2P.
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*ZMQ_PUB*::
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Socket to distribute data. Recv function is not implemented for this socket
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type. Messages are distributed in fanout fashion to all the peers.
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+
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Compatible peer sockets: ZMQ_SUB.
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*ZMQ_SUB*::
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Socket to subscribe for data. Send function is not implemented for this socket
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type. Initially, socket is subscribed for no messages. Use ZMQ_SUBSCRIBE option
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to specify which messages to subscribe for.
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+
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Compatible peer sockets: ZMQ_PUB.
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*ZMQ_REQ*::
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Socket to send requests and receive replies. Requests are load-balanced among
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all the peers. This socket type allows only an alternated sequence of send's
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and recv's.
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+
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Compatible peer sockets: ZMQ_REP, ZMQ_XREP.
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*ZMQ_REP*::
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Socket to receive requests and send replies. This socket type allows only an
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alternated sequence of recv's and send's. Each send is routed to the peer that
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issued the last received request.
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Compatible peer sockets: ZMQ_REQ, ZMQ_XREQ.
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*ZMQ_XREQ*::
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Special socket type to be used in request/reply middleboxes such as
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linkzmq:zmq_queue[7]. Requests forwarded using this socket type should be
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tagged by a proper prefix identifying the original requester. Replies received
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2010-02-23 10:01:54 +01:00
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by this socket are tagged with a proper prefix that can be use to route the
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2010-02-10 16:18:46 +01:00
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reply back to the original requester.
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+
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Compatible peer sockets: ZMQ_REP, ZMQ_XREP.
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*ZMQ_XREP*::
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Special socket type to be used in request/reply middleboxes such as
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linkzmq:zmq_queue[7]. Requests received using this socket are already properly
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tagged with prefix identifying the original requester. When sending a reply via
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XREP socket the message should be tagged with a prefix from a corresponding
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request.
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+
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Compatible peer sockets: ZMQ_REQ, ZMQ_XREQ.
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*ZMQ_UPSTREAM*::
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Socket to receive messages from up the stream. Messages are fair-queued from
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among all the connected peers. Send function is not implemented for this socket
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type.
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Compatible peer sockets: ZMQ_DOWNSTREAM.
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*ZMQ_DOWNSTREAM*::
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Socket to send messages down stream. Messages are load-balanced among all the
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connected peers. Recv function is not implemented for this socket type.
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Compatible peer sockets: ZMQ_UPSTREAM.
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RETURN VALUE
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------------
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Function returns socket handle is successful. Otherwise it returns NULL and
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sets errno to one of the values below.
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ERRORS
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------
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*EINVAL*::
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invalid socket type.
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*EMTHREAD*::
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the number of application threads allowed to own 0MQ sockets was exceeded.
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See 'app_threads' parameter to 'zmq_init' function.
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EXAMPLE
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-------
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----
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void *s = zmq_socket (context, ZMQ_PUB);
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assert (s);
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int rc = zmq_bind (s, "tcp://192.168.0.1:5555");
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assert (rc == 0);
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----
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SEE ALSO
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--------
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linkzmq:zmq_init[3]
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linkzmq:zmq_setsockopt[3]
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linkzmq:zmq_bind[3]
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linkzmq:zmq_connect[3]
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linkzmq:zmq_send[3]
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linkzmq:zmq_flush[3]
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linkzmq:zmq_recv[3]
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AUTHOR
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------
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Martin Sustrik <sustrik at 250bpm dot com>
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