我发现这个软件包非常有用，非常简单:https://github.com/amphp/parallel-functions

<?php

use function Amp\ParallelFunctions\parallelMap;
use function Amp\Promise\wait;

$responses = wait(parallelMap([
    'https://google.com/',
    'https://github.com/',
    'https://stackoverflow.com/',
], function ($url) {
    return file_get_contents($url);
}));

它将并行加载所有3个url。 您还可以在闭包中使用类实例方法。

例如，我使用Laravel扩展基于这个包https://github.com/spatie/laravel-collection-macros#parallelmap

这是我的代码:

    /**
     * Get domains with all needed data
     */
    protected function getDomainsWithdata(): Collection
    {
        return $this->opensrs->getDomains()->parallelMap(function ($domain) {
            $contact = $this->opensrs->getDomainContact($domain);
            $contact['domain'] = $domain;
            return $contact;
        }, 10);
    }

它在10个并行线程中加载所有需要的数据，而不是在没有异步的情况下50秒，它在8秒内完成。

swoole扩展。https://github.com/matyhtf/swoole PHP的异步并发网络框架。

$client = new swoole_client(SWOOLE_SOCK_TCP, SWOOLE_SOCK_ASYNC);

$client->on("connect", function($cli) {
    $cli->send("hello world\n");
});

$client->on("receive", function($cli, $data){
    echo "Receive: $data\n";
});

$client->on("error", function($cli){
    echo "connect fail\n";
});

$client->on("close", function($cli){
    echo "close\n";
});

$client->connect('127.0.0.1', 9501, 0.5);

我之前接受的答案行不通。它仍在等待回应。这虽然工作，采取从我如何使一个异步GET请求在PHP?

function post_without_wait($url, $params)
{
    foreach ($params as $key => &$val) {
      if (is_array($val)) $val = implode(',', $val);
        $post_params[] = $key.'='.urlencode($val);
    }
    $post_string = implode('&', $post_params);

    $parts=parse_url($url);

    $fp = fsockopen($parts['host'],
        isset($parts['port'])?$parts['port']:80,
        $errno, $errstr, 30);

    $out = "POST ".$parts['path']." HTTP/1.1\r\n";
    $out.= "Host: ".$parts['host']."\r\n";
    $out.= "Content-Type: application/x-www-form-urlencoded\r\n";
    $out.= "Content-Length: ".strlen($post_string)."\r\n";
    $out.= "Connection: Close\r\n\r\n";
    if (isset($post_string)) $out.= $post_string;

    fwrite($fp, $out);
    fclose($fp);
}

Symfony HttpClient是异步的https://symfony.com/doc/current/components/http_client.html。

例如，你可以

use Symfony\Component\HttpClient\HttpClient;

$client = HttpClient::create();
$response1 = $client->request('GET', 'https://website1');
$response2 = $client->request('GET', 'https://website1');
$response3 = $client->request('GET', 'https://website1');
//these 3 calls with return immediately
//but the requests will fire to the website1 webserver

$response1->getContent(); //this will block until content is fetched
$response2->getContent(); //same 
$response3->getContent(); //same

class async_file_get_contents extends Thread{
    public $ret;
    public $url;
    public $finished;
        public function __construct($url) {
        $this->finished=false;
        $this->url=$url;
    }
        public function run() {
        $this->ret=file_get_contents($this->url);
        $this->finished=true;
    }
}
$afgc=new async_file_get_contents("http://example.org/file.ext");

你可以在PHP中使用非阻塞套接字和pecl扩展之一:

http://php.net/event http://php.net/libevent http://php.net/ev https://github.com/m4rw3r/php-libev

您可以使用库，它为您的代码和pecl扩展之间提供了一个抽象层:https://github.com/reactphp/event-loop

您还可以使用基于前面库的异步http-client: https://github.com/reactphp/http-client

查看ReactPHP的其他库:http://reactphp.org

使用异步模型时要小心。 我推荐在youtube上看这个视频:http://www.youtube.com/watch?v=MWNcItWuKpI