PHP 多任务秒级定时器的实现方法

 /***
 * Class Timer
 */
 class Timer extends SplMinHeap
 {
   /**
   * 比较根节点和新插入节点大小
   * @param mixed $value1
   * @param mixed $value2
   * @return int
   */
   protected function compare($value1, $value2)
   {
     if ($value1['timeout'] > $value2['timeout']) {
       return -1;
     }
     if ($value1['timeout'] < $value2['timeout']) {
       return 1;
     }
     return 0;
   }
   /**
   * 插入节点
   * @param mixed $value
   */
   public function insert($value)
   {
     $value['timeout'] = time() + $value['expire'];
     parent::insert($value);
   }
   /**
   * 监听
   * @param bool $debug
   */
   public function monitor($debug = false)
   {
     while (!$this->isEmpty()) {
       $this->exec($debug);
       usleep(1000);
     }
   }
   /**
   * 执行
   * @param $debug
   */
   private function exec($debug)
   {
     $hit = 0;
     $t1  = microtime(true);
     while (!$this->isEmpty()) {
       $node = $this->top();
       if ($node['timeout'] <= time()) {
         //出堆或入堆
         $node['repeat'] ? $this->insert($this->extract()) : $this->extract();
         $hit = 1;
         //开启子进程
         if (pcntl_fork() == 0) {
           empty($node['action']) ? '' : call_user_func($node['action']);
           exit(0);
         }
         //忽略子进程,子进程退出由系统回收
         pcntl_signal(SIGCLD, SIG_IGN);
       } else {
         break;
       }
     }
     $t2 = microtime(true);
     echo ($debug && $hit) ? '时间堆 - 调整耗时: ' . round($t2 - $t1, 3) . "秒\r\n" : '';
   }
 }

$timer = new Timer();
//注册 - 3s - 重复触发
$timer->insert(array('expire' => 3, 'repeat' => true, 'action' => function(){
  echo '3秒 - 重复 - hello world' . "\r\n";
}));
//注册 - 3s - 重复触发
$timer->insert(array('expire' => 3, 'repeat' => true, 'action' => function(){
  echo '3秒 - 重复 - gogo' . "\r\n";
}));
//注册 - 6s - 触发一次
$timer->insert(array('expire' => 6, 'repeat' => false, 'action' => function(){
  echo '6秒 - 一次 - hello xxxx' . "\r\n";
}));
//监听
$timer->monitor(false);