Geen cache-versie.
Caching uitgeschakeld. Standaardinstelling voor deze pagina:ingeschakeld (code LNG204)
Als het scherm te langzaam is, kunt u de gebruikersmodus uitschakelen om de cacheversie te bekijken.
Examples
Example #1 Simple timers
<?php
// Create and start timer firing after 2 seconds
$w1 = new EvTimer(2, 0, function () {
echo "2 seconds elapsed\n";
});
// Create and launch timer firing after 2 seconds repeating each second
// until we manually stop it
$w2 = new EvTimer(2, 1, function ($w) {
echo "is called every second, is launched after 2 seconds\n";
echo "iteration = ", Ev::iteration(), PHP_EOL;
// Stop the watcher after 5 iterations
Ev::iteration() == 5 and $w->stop();
// Stop the watcher if further calls cause more than 10 iterations
Ev::iteration() >= 10 and $w->stop();
});
// Create stopped timer. It will be inactive until we start it ourselves
$w_stopped = EvTimer::createStopped(10, 5, function($w) {
echo "Callback of a timer created as stopped\n";
// Stop the watcher after 2 iterations
Ev::iteration() >= 2 and $w->stop();
});
// Loop until Ev::stop() is called or all of watchers stop
Ev::run();
// Start and look if it works
$w_stopped->start();
echo "Run single iteration\n";
Ev::run(Ev::RUN_ONCE);
echo "Restart the second watcher and try to handle the same events, but don't block\n";
$w2->again();
Ev::run(Ev::RUN_NOWAIT);
$w = new EvTimer(10, 0, function() {});
echo "Running a blocking loop\n";
Ev::run();
echo "END\n";
?>
The above example will output something similar to:
2 seconds elapsed is called every second, is launched after 2 seconds iteration = 1 is called every second, is launched after 2 seconds iteration = 2 is called every second, is launched after 2 seconds iteration = 3 is called every second, is launched after 2 seconds iteration = 4 is called every second, is launched after 2 seconds iteration = 5 Run single iteration Callback of a timer created as stopped Restart the second watcher and try to handle the same events, but don't block Running a blocking loop is called every second, is launched after 2 seconds iteration = 8 is called every second, is launched after 2 seconds iteration = 9 is called every second, is launched after 2 seconds iteration = 10 END
Example #2 Periodic timer. Tick each 10.5 seconds
<?php
$w = new EvPeriodic(0., 10.5, NULL, function ($w, $revents) {
echo time(), PHP_EOL;
});
Ev::run();
?>
Example #3 Periodic timer. Use reschedule callback
<?php
// Tick each 10.5 seconds
function reschedule_cb ($watcher, $now) {
return $now + (10.5. - fmod($now, 10.5));
}
$w = new EvPeriodic(0., 0., "reschedule_cb", function ($w, $revents) {
echo time(), PHP_EOL;
});
Ev::run();
?>
Example #4 Periodic timer. Tick every 10.5 seconds starting at now
<?php
// Tick every 10.5 seconds starting at now
$w = new EvPeriodic(fmod(Ev::now(), 10.5), 10.5, NULL, function ($w, $revents) {
echo time(), PHP_EOL;
});
Ev::run();
?>
Example #5 Wait until STDIN is readable
<?php
// Wait until STDIN is readable
$w = new EvIo(STDIN, Ev::READ, function ($watcher, $revents) {
echo "STDIN is readable\n";
});
Ev::run(Ev::RUN_ONCE);
?>
Example #6 Use some async I/O to access a socket
<?php
/* Use some async I/O to access a socket */
// `sockets' extension still logs warnings
// for EINPROGRESS, EAGAIN/EWOULDBLOCK etc.
error_reporting(E_ERROR);
$e_nonblocking = array (/*EAGAIN or EWOULDBLOCK*/11, /*EINPROGRESS*/115);
// Get the port for the WWW service
$service_port = getservbyname('www', 'tcp');
// Get the IP address for the target host
$address = gethostbyname('google.co.uk');
// Create a TCP/IP socket
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($socket === FALSE) {
echo "socket_create() failed: reason: "
.socket_strerror(socket_last_error()) . "\n";
}
// Set O_NONBLOCK flag
socket_set_nonblock($socket);
// Abort on timeout
$timeout_watcher = new EvTimer(10.0, 0., function () use ($socket) {
socket_close($socket);
Ev::stop(Ev::BREAK_ALL);
});
// Make HEAD request when the socket is writable
$write_watcher = new EvIo($socket, Ev::WRITE, function ($w)
use ($socket, $timeout_watcher, $e_nonblocking)
{
// Stop timeout watcher
$timeout_watcher->stop();
// Stop write watcher
$w->stop();
$in = "HEAD / HTTP/1.1\r\n";
$in .= "Host: google.co.uk\r\n";
$in .= "Connection: Close\r\n\r\n";
if (!socket_write($socket, $in, strlen($in))) {
trigger_error("Failed writing $in to socket", E_USER_ERROR);
}
$read_watcher = new EvIo($socket, Ev::READ, function ($w, $re)
use ($socket, $e_nonblocking)
{
// Socket is readable. recv() 20 bytes using non-blocking mode
$ret = socket_recv($socket, $out, 20, MSG_DONTWAIT);
if ($ret) {
echo $out;
} elseif ($ret === 0) {
// All read
$w->stop();
socket_close($socket);
return;
}
// Caught EINPROGRESS, EAGAIN, or EWOULDBLOCK
if (in_array(socket_last_error(), $e_nonblocking)) {
return;
}
$w->stop();
socket_close($socket);
});
Ev::run();
});
$result = socket_connect($socket, $address, $service_port);
Ev::run();
?>
The above example will output something similar to:
HTTP/1.1 301 Moved Permanently Location: http://www.google.co.uk/ Content-Type: text/html; charset=UTF-8 Date: Sun, 23 Dec 2012 16:08:27 GMT Expires: Tue, 22 Jan 2013 16:08:27 GMT Cache-Control: public, max-age=2592000 Server: gws Content-Length: 221 X-XSS-Protection: 1; mode=block X-Frame-Options: SAMEORIGIN Connection: close
Example #7 Embedding one loop into another
<?php
/*
* Try to get an embeddable event loop and embed it into the default event loop.
* If it is impossible, use the default
* loop. The default loop is stored in $loop_hi, while the embeddable loop is
* stored in $loop_lo(which is $loop_hi in the case no embeddable loop can be
* used).
*
* Sample translated to PHP
* http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#Examples_CONTENT-9
*/
$loop_hi = EvLoop::defaultLoop();
$loop_lo = NULL;
$embed = NULL;
/*
* See if there is a chance of getting one that works
* (flags' value of 0 means autodetection)
*/
$loop_lo = Ev::embeddableBackends() & Ev::recommendedBackends()
? new EvLoop(Ev::embeddableBackends() & Ev::recommendedBackends())
: 0;
if ($loop_lo) {
$embed = new EvEmbed($loop_lo, function () {});
} else {
$loop_lo = $loop_hi;
}
?>
Example #8 Embedding loop created with kqueue backend into the default loop
<?php
/*
* Check if kqueue is available but not recommended and create a kqueue backend
* for use with sockets (which usually work with any kqueue implementation).
* Store the kqueue/socket-only event loop in loop_socket. (One might optionally
* use EVFLAG_NOENV, too)
*
* Example borrowed from
* http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#Examples_CONTENT-9
*/
$loop = EvLoop::defaultLoop();
$socket_loop = NULL;
$embed = NULL;
if (Ev::supportedBackends() & ~Ev::recommendedBackends() & Ev::BACKEND_KQUEUE) {
if (($socket_loop = new EvLoop(Ev::BACKEND_KQUEUE))) {
$embed = new EvEmbed($loop);
}
}
if (!$socket_loop) {
$socket_loop = $loop;
}
// Now use $socket_loop for all sockets, and $loop for anything else
?>
Example #9 Handle SIGTERM signal
<?php
$w = new EvSignal(SIGTERM, function ($watcher) {
echo "SIGTERM received\n";
$watcher->stop();
});
Ev::run();
?>
Example #10 Monitor changes of /var/log/messages
<?php
// Use 10 second update interval.
$w = new EvStat("/var/log/messages", 8, function ($w) {
echo "/var/log/messages changed\n";
$attr = $w->attr();
if ($attr['nlink']) {
printf("Current size: %ld\n", $attr['size']);
printf("Current atime: %ld\n", $attr['atime']);
printf("Current mtime: %ld\n", $attr['mtime']);
} else {
fprintf(STDERR, "`messages` file is not there!");
$w->stop();
}
});
Ev::run();
?>
Example #11 Monotor changes of /var/log/messages. Avoid missing updates by means of one second delay
<?php
$timer = EvTimer::createStopped(0., 1.02, function ($w) {
$w->stop();
$stat = $w->data;
// 1 second after the most recent change of the file
printf("Current size: %ld\n", $stat->attr()['size']);
});
$stat = new EvStat("/var/log/messages", 0., function () use ($timer) {
// Reset timer watcher
$timer->again();
});
$timer->data = $stat;
Ev::run();
?>
Example #12 Process status changes
<?php
$pid = pcntl_fork();
if ($pid == -1) {
fprintf(STDERR, "pcntl_fork failed\n");
} elseif ($pid) {
$w = new EvChild($pid, FALSE, function ($w, $revents) {
$w->stop();
printf("Process %d exited with status %d\n", $w->rpid, $w->rstatus);
});
Ev::run();
// Protect against Zombies
pcntl_wait($status);
} else {
//Forked child
exit(2);
}
?>
Vertaling niet beschikbaar
De PHP-handleiding is nog niet in het Nederlands vertaald, dus het scherm is in het Engels. Als u wilt, kunt u het ook in het Frans of in het Duits raadplegen.
Als je de moed voelt, kun je je vertaling aanbieden ;-)
Nederlandse vertaling
U hebt gevraagd om deze site in het Nederlands te bezoeken. Voor nu wordt alleen de interface vertaald, maar nog niet alle inhoud.Als je me wilt helpen met vertalingen, is je bijdrage welkom. Het enige dat u hoeft te doen, is u op de site registreren en mij een bericht sturen waarin u wordt gevraagd om u toe te voegen aan de groep vertalers, zodat u de gewenste pagina's kunt vertalen. Een link onderaan elke vertaalde pagina geeft aan dat u de vertaler bent en heeft een link naar uw profiel.
Bij voorbaat dank.
Document heeft de 30/01/2003 gemaakt, de laatste keer de 26/10/2018 gewijzigd
Bron van het afgedrukte document:https://www.gaudry.be/nl/php-rf-ev.examples.html
De infobrol is een persoonlijke site waarvan de inhoud uitsluitend mijn verantwoordelijkheid is. De tekst is beschikbaar onder CreativeCommons-licentie (BY-NC-SA). Meer info op de gebruiksvoorwaarden en de auteur.
Referenties
Deze verwijzingen en links verwijzen naar documenten die geraadpleegd zijn tijdens het schrijven van deze pagina, of die aanvullende informatie kunnen geven, maar de auteurs van deze bronnen kunnen niet verantwoordelijk worden gehouden voor de inhoud van deze pagina.
De auteur Deze site is als enige verantwoordelijk voor de manier waarop de verschillende concepten, en de vrijheden die met de referentiewerken worden genomen, hier worden gepresenteerd. Vergeet niet dat u meerdere broninformatie moet doorgeven om het risico op fouten te verkleinen.
