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Diffstat (limited to 'doc/zmq_poll.txt')
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diff --git a/doc/zmq_poll.txt b/doc/zmq_poll.txt deleted file mode 100644 index ccdbaea..0000000 --- a/doc/zmq_poll.txt +++ /dev/null @@ -1,129 +0,0 @@ -zmq_poll(3) -=========== - - -NAME ----- -zmq_poll - input/output multiplexing - - -SYNOPSIS --------- - -*int zmq_poll (zmq_pollitem_t '*items', int 'nitems', long 'timeout');* - - -DESCRIPTION ------------ -The _zmq_poll()_ function provides a mechanism for applications to multiplex -input/output events in a level-triggered fashion over a set of sockets. Each -member of the array pointed to by the 'items' argument is a *zmq_pollitem_t* -structure. The 'nitems' argument specifies the number of items in the 'items' -array. The *zmq_pollitem_t* structure is defined as follows: - -["literal", subs="quotes"] -typedef struct -{ - void '*socket'; - int 'fd'; - short 'events'; - short 'revents'; -} zmq_pollitem_t; - -For each *zmq_pollitem_t* item, _zmq_poll()_ shall examine either the 0MQ -socket referenced by 'socket' *or* the standard socket specified by the file -descriptor 'fd', for the event(s) specified in 'events'. If both 'socket' and -'fd' are set in a single *zmq_pollitem_t*, the 0MQ socket referenced by -'socket' shall take precedence and the value of 'fd' shall be ignored. - -For each *zmq_pollitem_t* item, _zmq_poll()_ shall first clear the 'revents' -member, and then indicate any requested events that have occurred by setting the -bit corresponding to the event condition in the 'revents' member. - -If none of the requested events have occurred on any *zmq_pollitem_t* item, -_zmq_poll()_ shall wait 'timeout' milliseconds for an event to occur on -any of the requested items. If the value of 'timeout' is `0`, _zmq_poll()_ -shall return immediately. If the value of 'timeout' is `-1`, _zmq_poll()_ shall -block indefinitely until a requested event has occurred on at least one -*zmq_pollitem_t*. - -The 'events' and 'revents' members of *zmq_pollitem_t* are bit masks constructed -by OR'ing a combination of the following event flags: - -*ZMQ_POLLIN*:: -For 0MQ sockets, at least one message may be received from the 'socket' without -blocking. For standard sockets this is equivalent to the 'POLLIN' flag of the -_poll()_ system call and generally means that at least one byte of data may be -read from 'fd' without blocking. - -*ZMQ_POLLOUT*:: -For 0MQ sockets, at least one message may be sent to the 'socket' without -blocking. For standard sockets this is equivalent to the 'POLLOUT' flag of the -_poll()_ system call and generally means that at least one byte of data may be -written to 'fd' without blocking. - -*ZMQ_POLLERR*:: -For standard sockets, this flag is passed through _zmq_poll()_ to the -underlying _poll()_ system call and generally means that some sort of error -condition is present on the socket specified by 'fd'. For 0MQ sockets this flag -has no effect if set in 'events', and shall never be returned in 'revents' by -_zmq_poll()_. - -NOTE: The _zmq_poll()_ function may be implemented or emulated using operating -system interfaces other than _poll()_, and as such may be subject to the limits -of those interfaces in ways not defined in this documentation. - - -RETURN VALUE ------------- -Upon successful completion, the _zmq_poll()_ function shall return the number -of *zmq_pollitem_t* structures with events signaled in 'revents' or `0` if no -events have been signaled. Upon failure, _zmq_poll()_ shall return `-1` and set -'errno' to one of the values defined below. - - -ERRORS ------- -*ETERM*:: -At least one of the members of the 'items' array refers to a 'socket' whose -associated 0MQ 'context' was terminated. -*EFAULT*:: -The provided 'items' was not valid (NULL). -*EINTR*:: -The operation was interrupted by delivery of a signal before any events were -available. - - -EXAMPLE -------- -.Polling indefinitely for input events on both a 0MQ socket and a standard socket. ----- -zmq_pollitem_t items [2]; -/* First item refers to 0MQ socket 'socket' */ -items[0].socket = socket; -items[0].events = ZMQ_POLLIN; -/* Second item refers to standard socket 'fd' */ -items[1].socket = NULL; -items[1].fd = fd; -items[1].events = ZMQ_POLLIN; -/* Poll for events indefinitely */ -int rc = zmq_poll (items, 2, -1); -assert (rc >= 0); -/* Returned events will be stored in items[].revents */ ----- - - -SEE ALSO --------- -linkzmq:zmq_socket[3] -linkzmq:zmq_send[3] -linkzmq:zmq_recv[3] -linkzmq:zmq[7] - -Your operating system documentation for the _poll()_ system call. - - -AUTHORS -------- -The 0MQ documentation was written by Martin Sustrik <sustrik@250bpm.com> and -Martin Lucina <martin@lucina.net>. |