思路很简单:

开一个子进程处理异步事务，处理完之后，通过管道告诉父进程，并将返回数据写入管道

代码如下:

AsynHttpClient.php

    url = $url;        $this->callback = $callback;        $this->run();    }    public function run()    {        $this->process = new swoole_process([$this, "callback"], true);         $this->process->start();        swoole_event_add($this->process->pipe, function($pipe) {            $content = $this->process->read();            call_user_func($this->callback, $content);            swoole_event_del($this->process->pipe);        });    }    public function callback(swoole_process $process)    {        $ch = curl_init($this->url);        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);        $content = curl_exec($ch);        curl_close($ch);                $process->write($content);    }}

index.php

require 'AsynHttpClient.php';new AsynHttpClient("http://127.0.0.1:9000/api.php", function($data) {   print_r($data);});echo 1;

api.php

     'ok',  'data' => 'hello',]);

php -S 127.0.0.1:9000

可以看到运行结果是1在前面, 证明是异步执行的.

其实通过php中的pcntl_fork和libevent也可以实现, 不需要借助swoole, 但是swoole提供的process确实很好用