ZMQPoll::poll
(PECL zmq >= 0.5.0)
ZMQPoll::poll — Poll the items
说明
&$readable
, array &$writable
[, int $timeout = -1
] ) : int
Polls the items in the current poll set. The readable and writable items are returned in the
readable and writable parameters.
ZMQPoll::getLastErrors() can be used to check if there were errors.
参数
-
readable -
Array where readable ZMQSockets/PHP streams are returned. The array will be cleared at the beginning of the operation.
-
writable -
Array where writable ZMQSockets/PHP streams are returned. The array will be cleared at the beginning of the operation.
-
timeout -
Timeout for the operation. -1 means that poll waits until at least one item has activity. Please note that starting from version 1.0.0 the poll timeout is defined in milliseconds, rather than microseconds.
范例
Example #1 A ZMQPoll() example
Create a simple poll server
<?php
/* Create socket, request-reply pattern (reply socket) */
$context = new ZMQContext();
$server = $context->getSocket(ZMQ::SOCKET_REP);
/* Bind to port 5555 on 127.0.0.1 */
$server->bind("tcp://127.0.0.1:5555");
/* Create new pollset for incoming/outgoing message */
$poll = new ZMQPoll();
/* Add the object and listen for poll in/out */
$id = $poll->add($server, ZMQ::POLL_IN | ZMQ::POLL_OUT);
echo "Added object with id " . $id . "\n";
/* Initialise readable and writable arrays */
$readable = array();
$writable = array();
while (true) {
/* Amount of events retrieved */
$events = 0;
try {
/* Poll until there is something to do */
$events = $poll->poll($readable, $writable, -1);
$errors = $poll->getLastErrors();
if (count($errors) > 0) {
foreach ($errors as $error) {
echo "Error polling object " . $error . "\n";
}
}
} catch (ZMQPollException $e) {
echo "poll failed: " . $e->getMessage() . "\n";
}
if ($events > 0) {
/* Loop through readable objects and recv messages */
foreach ($readable as $r) {
try {
echo "Received message: " . $r->recv() . "\n";
} catch (ZMQException $e) {
echo "recv failed: " . $e->getMessage() . "\n";
}
}
/* Loop through writable and send back messages */
foreach ($writable as $w) {
try {
$w->send("Got it!");
} catch (ZMQException $e) {
echo "send failed: " . $e->getMessage() . "\n";
}
}
}
}
?>
返回值
Returns an integer representing amount of items with activity. Throws ZMQPollException on error.