phpマルチタスクプログラムインスタンス解析

phpマルチタスクプログラムの実装方法を例として簡単に解析し、具体的なコードは以下の通りである.

_pref = 0;
  }
  
  public static function getInstance($file) {
    if (null == self::$_instance) {
      self::$_instance = new self;
    }
    
    $descriptor = array(
    0 => array("pipe", "r"),
    1 => array("pipe", "w"),
    2 => array("file", "./error-output.txt", "a"),
    );
    self::$_instance->_pref = proc_open("php -q $file", $descriptor, self::$_instance->_pipes);
    return true;
  }
  
  public function __destruct() {
    proc_close($this->_pref);
    $this->_pref = null;
  }
}
//     
$file = __FILE__;
if(empty($argv[1])) {
  $t2 = Thread::getInstance("$file 1");
  $t3 = Thread::getInstance("$file 2");
  $t4 = Thread::getInstance("$file 3");
  $t5 = Thread::getInstance("$file 4");
  $t5 = Thread::getInstance("$file 5");
  $t5 = Thread::getInstance("$file 6");
  $t2 = Thread::getInstance("$file 7");
  $t3 = Thread::getInstance("$file 8");
  $t4 = Thread::getInstance("$file 9");
  $t5 = Thread::getInstance("$file 10");
  $t5 = Thread::getInstance("$file 11");
  $t5 = Thread::getInstance("$file 12");
  echo "Main thread done
";
} else {
  $somecontent = "\r
//~~~~~~~~~~~~-       ：" . $argv[1];
  sleep(mt_rand(0, 3));
  $handle = fopen($file, 'a+');
  fwrite($handle, $somecontent);
}