php多任务程序实例解析

<?php
error_reporting(e_all);
set_time_limit(0);
/**
* php多任务程序的实现
* 借助proc_open
* 其实该叫进程(process)
* 能启动多进程，你可以使用你的想象力做你想做的了，以后再写个能用的
* 如果你是在linux上跑php，并且启用pcntl模块后，使用pcntl函数该更好
* 
*/
class thread {
  protected $_pref; // process reference
  protected static $_instance = null;
  protected $_pipes;
  
  private function __construct() {
    $this->_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;
  }
}
// 测试代码
$file = __file__;
if(empty($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\n";
} else {
  $somecontent = "\r\n//~~~~~~~~~~~~-这次请求序号是：" . $argv[1];
  sleep(mt_rand(0, 3));
  $handle = fopen($file, 'a+');
  fwrite($handle, $somecontent);
}