用于 PHP 的 pthreads 不在 Apache 中执行并行线程

我正在使用 PHP 的 pthreads 扩展.当我在 Windows 上从 cmd 执行 PHP 脚本时，我得到了并行线程，但是当我从 Apache 调用相同的脚本时，我得到了不同的结果，在我看来就像单线程执行一样.

I'm using the pthreads extension for PHP. When I execute the PHP script from cmd on Windows I get parallel threads but when I call the same script from Apache I get a different result and it seems to me like single thread execution.

是否应该为 Apache 进行任何配置以获得像 cmd(并行)这样的响应?

Is there any configuration that I should make for Apache to get response like cmd (parallel)?

class AsyncOperation extends Thread {
    public function __construct($arg){
        $this->arg = $arg;
    }

    public function run(){
        if($this->arg){
            for($i = 0; $i < 50; $i++) {
                echo "Yoo " . $this->arg . "<br>\n";
            }
        }
    }
}
$thread = new AsyncOperation("World ----------");
$thread2 = new AsyncOperation("Second -------------------------");
$thread->start();
$thread2->start();

for($i = 0; $i < 100; $i++) {
    echo "Standard <br>\n";
}

$thread->join();
$thread2->join();

示例代码在 cmd 中给出响应，例如:

Example code give response in cmd like:

Yoo World ----------<br>
Yoo World ----------<br>
Yoo World ----------<br>
Standard <br>
Standard <br>
Yoo World ----------<br>
Yoo Second -------------------------<br>
Standard <br>
Standard <br>

在网络浏览器中:

Yoo World ----------
Yoo World ----------
Yoo World ----------
Yoo World ----------
...
Yoo Second -------------------------
Yoo Second -------------------------
Yoo Second -------------------------
Yoo Second -------------------------
...
Standard 
Standard 
Standard 
Standard 
...

更新:在不同的浏览器上我得到不同的结果；此问题可能与缓冲区有关，我将对此进行调查.

Update: on different browsers I get different results; this problem might be related to buffer, which I'm going to investigate.