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86 lines
1.9 KiB
Plaintext
86 lines
1.9 KiB
Plaintext
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zmq_poll(3)
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===========
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NAME
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----
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zmq_poll - polls for events on a set of 0MQ and POSIX sockets
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SYNOPSIS
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--------
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'int zmq_poll (zmq_pollitem_t *items, int nitems, long timeout);'
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DESCRIPTION
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-----------
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Waits for the events specified by 'items' parameter. Number of items in the
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array is determined by 'nitems' argument. Each item in the array looks like
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this:
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----
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typedef struct
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{
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void *socket;
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int fd;
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short events;
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short revents;
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} zmq_pollitem_t;
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----
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0MQ socket to poll on is specified by 'socket'. In case you want to poll on
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standard POSIX socket, set 'socket' to NULL and fill the POSIX file descriptor
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to 'fd'. 'events' specifies which events to wait for. It's a combination of
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the values below. Once the call exits, 'revents' will be filled with events
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that have actually occured on the socket. The field will contain a combination
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of the values below.
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*ZMQ_POLLIN*::
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poll for incoming messages.
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*ZMQ_POLLOUT*::
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wait while message can be set socket. Poll will return if a message of at least
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one byte can be written to the socket. However, there is no guarantee that
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arbitrarily large message can be sent.
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'timeout' argument specifies an upper limit on the time for which 'zmq_poll'
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will block, in microseconds. Specifying a negative value in timeout means an
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infinite timeout.
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RETURN VALUE
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------------
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Function returns number of items signaled or -1 in the case of error.
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ERRORS
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------
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*EFAULT*::
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there's a 0MQ socket in the pollset belonging to a different application thread.
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*ENOTSUP*::
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0MQ context was initialised without ZMQ_POLL flag. I/O multiplexing is disabled.
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EXAMPLE
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-------
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----
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zmq_pollitem_t items [2];
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items [0].socket = s;
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items [0].events = ZMQ_POLLIN;
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items [1].socket = NULL;
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items [1].fd = my_fd;
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items [1].events = ZMQ_POLLIN;
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int rc = zmq_poll (items, 2);
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assert (rc != -1);
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----
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SEE ALSO
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--------
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linkzmq:zmq_socket[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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