PHP定时执行任务实现方法详解（Timer）

<?php
 /**
 *定时器
 */
 class Timer
 {
  //保存所有定时任务
  public static $task = array();
 
   //定时间隔
   public static $time = 1;
 
   /**
  *开启服务
   *@param $time int
  */
  public static function run($time = null)
   {
   if($time)
    {
      self::$time = $time;
    }
    self::installHandler();
    pcntl_alarm(1);
   }
   /**
   *注册信号处理函数
   */
   public static function installHandler()
   {
    pcntl_signal(SIGALRM, array('Timer','signalHandler'));
   }
 
   /**
   *信号处理函数
   */
   public static function signalHandler()
   {
    self::task();
   //一次信号事件执行完成后,再触发下一次
   pcntl_alarm(self::$time);
   }
 
   /**
   *执行回调
   */
   public static function task()
   {
    if(empty(self::$task))
    {//没有任务,返回
      return ;
    }
    foreach(self::$task as $time => $arr)
   {
      $current = time();
   
     foreach($arr as $k => $job)
    {//遍历每一个任务
       $func = $job['func']; /*回调函数*/
       $argv = $job['argv']; /*回调函数参数*/
     $interval = $job['interval']; /*时间间隔*/
       $persist = $job['persist']; /*持久化*/
 
       if($current == $time)
       {//当前时间有执行任务
 
      //调用回调函数,并传递参数
        call_user_func_array($func, $argv);
      
      //删除该任务
        unset(self::$task[$time][$k]);
       }
       if($persist)
       {//如果做持久化,则写入数组,等待下次唤醒
        self::$task[$current+$interval][] = $job;
       }
    }
    if(empty(self::$task[$time]))
    {
     unset(self::$task[$time]);
    }
    }
   }
 
   /**
   *添加任务
   */
   public static function add($interval, $func, $argv = array(), $persist = false)
   {
    if(is_null($interval))
    {
     return;
    }
    $time = time()+$interval;
   //写入定时任务
   self::$task[$time][] = array('func'=>$func, 'argv'=>$argv, 'interval'=>$interval, 'persist'=>$persist);
   }
 
   /**
   *删除所有定时器任务
   */
   public function dellAll()
   {
    self::$task = array();
   }
 }

<?php
 
 class DoJob
 {
  public function job( $param = array() )
  {
   $time = time();
   echo "Time: {$time}, Func: ".get_class()."::".__FUNCTION__."(".json_encode($param).")\n";
  }
 }

<?php
 
 require_once(__DIR__."/Timer.php");
 require_once(__DIR__."/DoJob.php");
 
 
 Timer::dellAll();
 
 Timer::add( 1, array('DoJob','job'), array(),true);
 
 Timer::add( 3, array('DoJob','job'),array('a'=>1), false);
 
 echo "Time start: ".time()."\n";
 Timer::run();
 
 while(1)
 {
  sleep(1);
  pcntl_signal_dispatch();
 }