如何在 PHP 应用程序中使用多线程 [英] How can one use multi threading in PHP applications

问题描述

是否有一种现实的方法可以在 PHP 中实现多线程模型，无论是真实的，还是只是模拟它.前段时间有人建议您可以强制操作系统加载 PHP 可执行文件的另一个实例并处理其他并发进程.

Is there a realistic way of implementing a multi-threaded model in PHP whether truly, or just simulating it. Some time back it was suggested that you could force the operating system to load another instance of the PHP executable and handle other simultaneous processes.

这样做的问题是，当 PHP 代码执行完毕后，PHP 实例仍保留在内存中，因为无法从 PHP 内部杀死它.因此，如果您正在模拟多个线程，您可以想象会发生什么.所以我仍在寻找一种可以在 PHP 中有效地完成或模拟多线程的方法.有什么想法吗?

The problem with this is that when the PHP code finished executing the PHP instance remains in memory because there is no way to kill it from within PHP. So if you are simulating several threads you can imagine whats going to happen. So I am still looking for a way multi-threading can be done or simulated effectively from within PHP. Any ideas?

推荐答案

php 可以实现多线程

是的，您可以使用 pthreads

来自 PHP 文档:

pthreads 是一个面向对象的 API，它提供了 PHP 中多线程处理所需的所有工具.PHP 应用程序可以创建、读取、写入、执行和同步线程、工作线程和线程对象.

pthreads is an object-orientated API that provides all of the tools needed for multi-threading in PHP. PHP applications can create, read, write, execute and synchronize with Threads, Workers and Threaded objects.

警告:pthreads 扩展不能在 Web 服务器环境中使用.因此，PHP 中的线程应仅适用于基于 CLI 的应用程序.

Warning: The pthreads extension cannot be used in a web server environment. Threading in PHP should therefore remain to CLI-based applications only.

简单测试

#!/usr/bin/php
<?php
class AsyncOperation extends Thread {

    public function __construct($arg) {
        $this->arg = $arg;
    }

    public function run() {
        if ($this->arg) {
            $sleep = mt_rand(1, 10);
            printf('%s: %s  -start -sleeps %d' . "
", date("g:i:sa"), $this->arg, $sleep);
            sleep($sleep);
            printf('%s: %s  -finish' . "
", date("g:i:sa"), $this->arg);
        }
    }
}

// Create a array
$stack = array();

//Initiate Multiple Thread
foreach ( range("A", "D") as $i ) {
    $stack[] = new AsyncOperation($i);
}

// Start The Threads
foreach ( $stack as $t ) {
    $t->start();
}

?>

第一次运行

12:00:06pm:     A  -start -sleeps 5
12:00:06pm:     B  -start -sleeps 3
12:00:06pm:     C  -start -sleeps 10
12:00:06pm:     D  -start -sleeps 2
12:00:08pm:     D  -finish
12:00:09pm:     B  -finish
12:00:11pm:     A  -finish
12:00:16pm:     C  -finish

第二次运行

12:01:36pm:     A  -start -sleeps 6
12:01:36pm:     B  -start -sleeps 1
12:01:36pm:     C  -start -sleeps 2
12:01:36pm:     D  -start -sleeps 1
12:01:37pm:     B  -finish
12:01:37pm:     D  -finish
12:01:38pm:     C  -finish
12:01:42pm:     A  -finish

真实世界的例子

error_reporting(E_ALL);
class AsyncWebRequest extends Thread {
    public $url;
    public $data;

    public function __construct($url) {
        $this->url = $url;
    }

    public function run() {
        if (($url = $this->url)) {
            /*
             * If a large amount of data is being requested, you might want to
             * fsockopen and read using usleep in between reads
             */
            $this->data = file_get_contents($url);
        } else
            printf("Thread #%lu was not provided a URL
", $this->getThreadId());
    }
}

$t = microtime(true);
$g = new AsyncWebRequest(sprintf("http://www.google.com/?q=%s", rand() * 10));
/* starting synchronization */
if ($g->start()) {
    printf("Request took %f seconds to start ", microtime(true) - $t);
    while ( $g->isRunning() ) {
        echo ".";
        usleep(100);
    }
    if ($g->join()) {
        printf(" and %f seconds to finish receiving %d bytes
", microtime(true) - $t, strlen($g->data));
    } else
        printf(" and %f seconds to finish, request failed
", microtime(true) - $t);
}

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