popen()/proc_open()即使在Windows中也可以并行工作。

最常见的陷阱是“fread/stream_get_contents”没有while循环。一旦你试图从正在运行的进程中fread()，它将阻塞在它之后运行的进程的输出(因为fread()等待至少一个字节到达)

添加stream_select()。最接近的类比是“foreach with timeout but for streams”，你传递几个数组来读写，每次调用stream_select()都会选择一个或多个流。函数通过引用更新原始数组，所以不要忘记在下次调用之前将其恢复到所有流。函数给它们一些时间来读或写。如果没有内容控制返回，允许我们重试循环。

// sleep.php
set_error_handler(function ($severity, $error, $file, $line) {
    throw new ErrorException($error, -1, $severity, $file, $line);
});

$sleep = $argv[ 1 ];

sleep($sleep);

echo $sleep . PHP_EOL;

exit(0);

// run.php
<?php

$procs = [];
$pipes = [];

$cmd = 'php %cd%/sleep.php';

$desc = [
    0 => [ 'pipe', 'r' ],
    1 => [ 'pipe', 'w' ],
    2 => [ 'pipe', 'a' ],
];

for ( $i = 0; $i < 10; $i++ ) {
    $iCmd = $cmd . ' ' . ( 10 - $i ); // add SLEEP argument to each command 10, 9, ... etc.

    $proc = proc_open($iCmd, $desc, $pipes[ $i ], __DIR__);

    $procs[ $i ] = $proc;
}

$stdins = array_column($pipes, 0);
$stdouts = array_column($pipes, 1);
$stderrs = array_column($pipes, 2);

while ( $procs ) {
    foreach ( $procs as $i => $proc ) {
        // @gzhegow > [OR] you can output while script is running (if child never finishes)
        $read = [ $stdins[ $i ] ];
        $write = [ $stdouts[ $i ], $stderrs[ $i ] ];
        $except = [];
        if (stream_select($read, $write, $except, $seconds = 0, $microseconds = 1000)) {
            foreach ( $write as $stream ) {
                echo stream_get_contents($stream);
            }
        }

        $status = proc_get_status($proc);

        if (false === $status[ 'running' ]) {
            $status = proc_close($proc);
            unset($procs[ $i ]);

            echo 'STATUS: ' . $status . PHP_EOL;
        }

        // @gzhegow > [OR] you can output once command finishes
        // $status = proc_get_status($proc);
        //
        // if (false === $status[ 'running' ]) {
        //     if ($content = stream_get_contents($stderrs[ $i ])) {
        //         echo '[ERROR]' . $content . PHP_EOL;
        //     }
        //
        //     echo stream_get_contents($stdouts[ $i ]) . PHP_EOL;
        //
        //     $status = proc_close($proc);
        //     unset($procs[ $i ]);
        //
        //     echo 'STATUS: ' . $status . PHP_EOL;
        // }
    }

    usleep(1); // give your computer one tick to decide what thread should be used
}

// ensure you receive 1,2,3... but you've just run it 10,9,8...

exit(0);

取决于你要做什么，你也可以使用curl_multi来实现它。

为什么不用popen?

for ($i=0; $i<10; $i++) {
    // open ten processes
    for ($j = 0; $j < 10; $j++) {
        $pipe[$j] = popen('script2.php', 'w');
    }

    // wait for them to finish
    for ($j = 0; $j < 10; ++$j) {
        pclose($pipe[$j]);
    }
}

我知道这是一个老问题，但毫无疑问，PHPThreads对许多人都很有用

代码示例:

function threadproc($thread, $param) {
 
    echo "\tI'm a PHPThread.  In this example, I was given only one parameter: \"". print_r($param, true) ."\" to work with, but I can accept as many as you'd like!\n";
 
    for ($i = 0; $i < 10; $i++) {
        usleep(1000000);
        echo "\tPHPThread working, very busy...\n";
    }
 
    return "I'm a return value!";
}
 

$thread_id = phpthread_create($thread, array(), "threadproc", null, array("123456"));
 
echo "I'm the main thread doing very important work!\n";
 
for ($n = 0; $n < 5; $n++) {
    usleep(1000000);
    echo "Main thread...working!\n";
}
 
echo "\nMain thread done working.  Waiting on our PHPThread...\n";
 
phpthread_join($thread_id, $retval);
 
echo "\n\nOur PHPThread returned: " . print_r($retval, true) . "!\n";

需要PHP扩展:

posix pcntl 套接字

我已经在生产中使用这个库好几个月了。我花了很多精力让它看起来像在使用POSIX pthread。如果您熟悉pthread，那么您可以立即学习并非常有效地使用它。

在计算上，内部工作方式有很大不同，但实际上，功能几乎是相同的，包括语义和语法。

我用它编写了一个非常高效的WebSocket服务器，支持高吞吐率。对不起，我跑题了。我只是很兴奋，我终于把它发布了，我想看看它会帮助谁!

那么pcntl_fork呢?

检查我们的手册页的例子:PHP pcntl_fork

<?php

    $pid = pcntl_fork();
    if ($pid == -1) {
        die('could not fork');
    } else if ($pid) {
        // we are the parent
        pcntl_wait($status); //Protect against Zombie children
    } else {
        // we are the child
    }

?>

我知道这是一个老问题，但对于搜索的人来说，有一个用C编写的PECL扩展，现在提供了PHP多线程功能，它位于https://github.com/krakjoe/pthreads