PHP扩展ev示例翻译

2013-03-21

php的libev扩展
提供了一些类似nodejs异步调用的方式，
用途很多，如文件状态监视，流阻塞等待异步
pecl库的，默认不安装，需要自己在pecl下弄个过来
php manual地址：http://www.php.net/manual/zh/ev.examples.php
如果不知道libev是啥可以看这个http://dirlt.com/libev.html
这里罗列下具体手册内的代码，只翻译了关键注释
刚才由于对代码没有整理，竟然被过滤掉了……不能发html pre代码的博客编辑器好凄惨

//创建一个定时器，2秒后启动，不循环只执行一次 $w1 = new EvTimer(2, 0, function () { echo "2 seconds elapsed\n"; }); //创建一个定时器，2秒后启动，1秒执行一次 // 直到碰到指定代码停止 $w2 = new EvTimer(2, 1, function ($w) { echo "is called every second, is launched after 2 seconds\n"; echo "iteration = ", Ev::iteration(), PHP_EOL; //执行第五次停止 Ev::iteration() == 5 and $w->stop(); // Stop the watcher if further calls cause more than 10 iterations Ev::iteration() >= 10 and $w->stop(); }); //创建计时器，未激活，需要代码激活 $w_stopped = EvTimer::createStopped(10, 5, function($w) { echo "Callback of a timer created as stopped\n"; //事件产生两次后停止定时器 Ev::iteration() >= 2 and $w->stop(); }); //循环直到所有都关闭 Ev::run(); //启动并检查是否开始工作 $w_stopped->start(); echo "Run single iteration\n"; Ev::run(Ev::RUN_ONCE); echo "重启定时器，并尝试继续处理相同事件，但是这次是非阻塞的方式\n"; $w2->again(); Ev::run(Ev::RUN_NOWAIT); $w = new EvTimer(10, 0, function() {}); echo "阻塞方式运行\n"; Ev::run(); echo "END\n";

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//等待一直到STDIN准备好并可读 $w = new EvIo(STDIN, Ev::READ, function ($watcher, $revents) { echo "STDIN is readable\n"; }); Ev::run(Ev::RUN_ONCE);

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非阻塞
$e_nonblocking = array (11, 115); //获取www服务服务端口 $service_port = getservbyname('www', 'tcp'); //获取域名对应ip $address = gethostbyname('google.co.uk'); //创建socket通讯 $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); if ($socket === FALSE) { echo "socket_create() failed: reason: " .socket_strerror(socket_last_error()) . "\n"; } //表示非阻塞方式 socket_set_nonblock($socket); //如果在使用中超时自动关闭，这里用了evtimer $timeout_watcher = new EvTimer(10.0, 0., function () use ($socket) { socket_close($socket); Ev::stop(Ev::BREAK_ALL); }); //当socket可用后，进行发送接收操作 $write_watcher = new EvIo($socket, Ev::WRITE, function ($w) use ($socket, $timeout_watcher, $e_nonblocking) { //超时timer停用 $timeout_watcher->stop(); //停用evio监视 $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) { //非阻塞情况下从socket读取20字节数据 $ret = socket_recv($socket, $out, 20, MSG_DONTWAIT); if ($ret) { echo $out; } elseif ($ret === 0) { //读取完毕 $w->stop(); socket_close($socket); return; } //socket通讯错误 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();

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信号处理，当收到控制信号时自动启动
$w = new EvSignal(SIGTERM, function ($watcher) { echo "SIGTERM received\n"; $watcher->stop(); }); Ev::run();

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//指定文件修改监视当监视文件出现变化，则触发，每8秒检查一次 $w = new EvStat("/var/log/messages", 8, function ($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();

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进程状态监视
$pid = pcntl_fork(); if ($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); }