Php/docs/ev.examples
范例
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 $w->stop();});// Loop until Ev::stop() is called or all of watchers stopEv::run();// Start and look if it works$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";?>
以上例程的输出类似于：
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, $revents) { echo time(), PHP_EOL;});Ev::run();?>
Example #3 Periodic timer. Use reschedule callback
<?php// Tick each 10.5 secondsfunction reschedule_cb ($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 flagsocket_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();?>
以上例程的输出类似于：
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);}?>
