PHP多进程实例

<?php
header('content-type:text/html;charset=utf-8' );

// 必须加载扩展
if (!function_exists("pcntl_fork")) {
    die("pcntl extention is must !");
}
//总进程的数量
$totals = 3;
// 执行的脚本数量
$cmdArr = array();
// 执行的脚本数量的数组
for ($i = 0; $i < $totals; $i++) {
    $cmdArr[] = array("path" => __DIR__ . "/run.php",  'pid' =>$i ,'total' =>$totals);
}

/*
展开：$cmdArr
Array
(
    [0] => Array
        (
            [path] => /var/www/html/company/pcntl/run.php
            [pid] => 0
            [total] => 3
        )
    [1] => Array
        (
            [path] => /var/www/html/company/pcntl/run.php
            [pid] => 1
            [total] => 3
        )
    [2] => Array
        (
            [path] => /var/www/html/company/pcntl/run.php
            [pid] => 2
            [total] => 3
        )
)
*/

pcntl_signal(SIGCHLD, SIG_IGN);    //若是父进程不关心子进程何时结束,子进程结束后，内核会回收。
foreach ($cmdArr  as   $cmd) {
    $pid = pcntl_fork();    //建立子进程
    //父进程和子进程都会执行下面代码
    if ($pid == -1) {
        //错误处理：建立子进程失败时返回-1.
        die('could not fork');
    } else if ($pid) { //这里$pid>0
        //父进程会获得子进程号，因此这里是父进程执行的逻辑
        //若是不须要阻塞进程，而又想获得子进程的退出状态，则能够注释掉pcntl_wait($status)语句，或写成：
        pcntl_wait($status,WNOHANG); //等待子进程中断，防止子进程成为僵尸进程。
    } else { //这里$pid=0
        //子进程获得的$pid为0, 因此这里是子进程执行的逻辑。
        $path   = $cmd["path"];
        $pid = $cmd['pid'] ;
        $total = $cmd['total'] ;
        echo exec("/usr/bin/php {$path} {$pid} {$total}")."\n";
        exit(0) ;
    }
}
?>