public function start(){
  

  

  echo "Multi-process start\n";
  

  while (true){
  

  $this->parentRun();
  

  echo "当前任务数：" . self::$isfork . "\n";
  

  

  if(!$this->isFork()){
  

  echo "wait  " . $this->waitTime . "s\n";
  

  sleep($this->waitTime);
  

  continue;
  

  }
  

  

  echo date("Y-m-d h:m:s");
  

  if ( $this->childCount <= $this->max ){
  

  

  $deploy = array_pop(self::$queue);
  

  $pid=pcntl_fork();
  

  }else{
  

  

  usleep(10000);
  

  continue;
  

  }
  

  if ($pid == -1) {
  

  die("could not fork");
  

  } else if ($pid) {// we are the parent
  

  echo 'childNum:'.$pid.', maxNum:'.$this->max."\n";
  

  $this->childCount++;
  

  $this->forkMinus();
  

  echo 'childSum:' . $this->childCount."\n";
  

  } else {// we are the child
  

  $this->run($deploy);
  

  exit();
  

  }
  

  }
  

  }