浅谈PHP进程管理

<?php
define('PROC_MAX', 10);
define('PROC_MIN', 5);
 
$cmd = $argv[1];
$aPid = [];
$pidFile = __DIR__ . '/pid.pid';
$pid = file_get_contents($pidFile);
 
switch($cmd){
 case 'start' :
  if(posix_kill($pid, 0)){
   echo "gamelog process is already exsits!\n";
   return false;
  }
  //设置默认文件权限
  umask(022);
  //fork
  $pid = pcntl_fork();
  if($pid < 0){
   exit('fork error!');
  }else if($pid > 0){
   exit;
  }
  //脱离当前终端
  posix_setsid();
  //将当前工作目录更改为根目录
  chdir('/');
  //关闭文件描述符
  fclose(STDIN);
  fclose(STDOUT);
  fclose(STDERR);
  //重定向输入输出
  global $STDOUT, $STDERR;
  $STDOUT = fopen('/dev/null', 'a');
  $STDERR = fopen('/dev/null', 'a');
   
  cli_set_process_title('gamelog:master');
  $pid = posix_getpid();
  file_put_contents($pidFile, $pid);
  //闹钟信号
  pcntl_signal(SIGALRM, function() use (&$aPid) {
   pcntl_alarm(300);
   $workerNum = mt_rand(1, 20);//此处检测你需要的进程数
   $daemonNum = count($aPid);
    
   ($workerNum > PROC_MAX) && ($workerNum = PROC_MAX);
   if($daemonNum < $workerNum){
    $procNum = $workerNum - $daemonNum;
    $procNum = max(PROC_MIN, $procNum);
    for($p = 1; $p <= $procNum; $p++){
     $pid = pcntl_fork();
     if ($pid < 0) {
      exit('fork error!');
     } else if ($pid == 0) {
      cli_set_process_title('gamelog:worker');
      while (true) {
       //do your work
       usleep(100);
      }
      exit();
     } else {
      $aPid[] = $pid;
     }
    }
   }else if($daemonNum > $workerNum){
    $wokerNum = max($wokerNum, PROC_MIN);
    $killNum = $daemonNum - $workerNum;
    foreach($aPid as $key=>$pid){
     if(posix_kill($pid, SIGKILL)){
      unset($aPid[$key]);
      if(--$killNum <= 0){
       break;
      }
     }
    }
   }
  }, false);
   
  pcntl_signal(SIGUSR1, function() use (&$aPid, $pid){
   foreach($aPid as $key=>$chpid){
    if(!posix_kill($chpid, SIGKILL)){
     echo "kill child $chpid faild\n";
    }
   }
   posix_kill($pid, SIGKILL);
  }, false);
   
  pcntl_signal(SIGUSR2, function() use (&$aPid, $pid){
   foreach($aPid as $key=>$chpid){
    if(!posix_kill($chpid, SIGKILL)){
     echo "kill child $chpid faild\n";
    }
   }
   if(!posix_kill($pid, SIGALRM)){
    echo "restart gamelog faild\n";
   }
  }, false);
   
  posix_kill($pid, SIGALRM);
  while (true) {
   pcntl_signal_dispatch();
   $pid = pcntl_wait($status, WUNTRACED);//不阻塞
  }
  break;
  
 case 'stop' :
  if(!posix_kill($pid, SIGUSR1)){
   exit('stop gamelog process error!');
  }
  break;
 case 'reload' :
  if(!posix_kill($pid, SIGUSR2)){
   exit('restop gamelog process error!');
  }
  break;
 default :
  echo "Useage php signal.php start|stop|reload\n";
}