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diff --git a/doc/zmq_device.txt b/doc/zmq_device.txt deleted file mode 100644 index 10d7445..0000000 --- a/doc/zmq_device.txt +++ /dev/null @@ -1,99 +0,0 @@ -zmq_device(3) -============= - -NAME ----- -zmq_device - start built-in 0MQ device - - -SYNOPSIS --------- -*int zmq_device (int 'device', const void '*frontend', const void '*backend');* - - -DESCRIPTION ------------ -The _zmq_device()_ function starts a built-in 0MQ device. The 'device' argument is one of: - -'ZMQ_QUEUE':: - starts a queue device -'ZMQ_FORWARDER':: - starts a forwarder device -'ZMQ_STREAMER':: - starts a streamer device - -The device connects a frontend socket to a backend socket. Conceptually, data flows from frontend to backend. Depending on the socket types, replies may flow in the opposite direction. - -Before calling _zmq_device()_ you must set any socket options, and connect or bind both frontend and backend sockets. The two conventional device models are: - -*proxy*:: - bind frontend socket to an endpoint, and connect backend socket to downstream components. A proxy device model does not require changes to the downstream topology but that topology is static (any changes require reconfiguring the device). -*broker*:: - bind frontend socket to one endpoint and bind backend socket to a second endpoint. Downstream components must now connect into the device. A broker device model allows a dynamic downstream topology (components can come and go at any time). - -_zmq_device()_ runs in the current thread and returns only if/when the current context is closed. - - -QUEUE DEVICE ------------- -'ZMQ_QUEUE' creates a shared queue that collects requests from a set of clients, and distributes these fairly among a set of services. Requests are fair-queued from frontend connections and load-balanced between backend connections. Replies automatically return to the client that made the original request. - -This device is part of the 'request-reply' pattern. The frontend speaks to clients and the backend speaks to services. You should use 'ZMQ_QUEUE' with a 'ZMQ_XREP' socket for the frontend and a 'ZMQ_XREQ' socket for the backend. Other combinations are not documented. - -Refer to linkzmq:zmq_socket[3] for a description of these socket types. - - -FORWARDER DEVICE ----------------- -'ZMQ_FORWARDER' collects messages from a set of publishers and forwards these to a set of subscribers. You will generally use this to bridge networks, e.g. read on TCP unicast and forward on multicast. - -This device is part of the 'publish-subscribe' pattern. The frontend speaks to publishers and the backend speaks to subscribers. You should use 'ZMQ_FORWARDER' with a 'ZMQ_SUB' socket for the frontend and a 'ZMQ_PUB' socket for the backend. Other combinations are not documented. - -Refer to linkzmq:zmq_socket[3] for a description of these socket types. - - -STREAMER DEVICE ---------------- -'ZMQ_STREAMER' collects tasks from a set of pushers and forwards these to a set of pullers. You will generally use this to bridge networks. Messages are fair-queued from pushers and load-balanced to pullers. - -This device is part of the 'pipeline' pattern. The frontend speaks to pushers and the backend speaks to pullers. You should use 'ZMQ_STREAMER' with a 'ZMQ_PULL' socket for the frontend and a 'ZMQ_PUSH' socket for the backend. Other combinations are not documented. - -Refer to linkzmq:zmq_socket[3] for a description of these socket types. - - -RETURN VALUE ------------- -<<<<<<< HEAD -The _zmq_device()_ function shall not return if successful. Otherwise it shall -return `-1` and set 'errno' to one of the values defined below. - - -ERRORS ------- -The _zmq_device()_ function always returns `-1` and 'errno' set to *ETERM* (the 0MQ 'context' associated with either of the specified sockets was terminated). - - -EXAMPLE -------- -.Creating a queue broker ----- -// Create frontend and backend sockets -void *frontend = zmq_socket (context, ZMQ_XREP); -assert (backend); -void *backend = zmq_socket (context, ZMQ_XREQ); -assert (frontend); -// Bind both sockets to TCP ports -assert (zmq_bind (frontend, "tcp://*:5555") == 0); -assert (zmq_bind (backend, "tcp://*:5556") == 0); -// Start a queue device -zmq_device (ZMQ_QUEUE, frontend, backend); ----- - - -SEE ALSO --------- -linkzmq:zmq_bind[3] -linkzmq:zmq_connect[3] -linkzmq:zmq_socket[3] -linkzmq:zmq[7] - |