分享PHP-pcntl 实现多进程代码

PHP使用PCNTL系列的函数也能做到多进程处理一个事务。比如我需要从数据库中获取80w条的数据，再做一系列后续的处理，这个时候，用单进程？你可以等到明年今天了。。。所以应该使用pcntl函数了。

下面我们来看个实例

代码

    <?php
    $arChildId = array();

    for($i = 0; $i < 10; $i++)
    {
    $iPid = pcntl_fork();
    if($iPid == -1)
    {
      die('can\'t be forked.');
    }

    if($iPid)
    {
      # 主进程逻辑
      $arChildId[] = $iPid;
    }
    else
      {
      # 子进程逻辑
      $iPid = posix_getpid(); # 获取子进程的ID
      $iSeconds = rand(5, 30);
      echo '* Process '. $iPid. ' was created, and Executed, and Sleep '. $iSeconds. PHP_EOL;
      excuteProcess($iPid, $iSeconds);
      exit();
    }
    }

    while(count($arChildId) > 0)
    {
    foreach($arChildId as $iKey=> $iPid)
    {
      $res = pcntl_waitpid($iPid, $status, WNOHANG);

      if($res == -1 || $res > 0)
      {
        unset($arChildId[$iKey]);
        echo '* Sub process: '. $iPid. ' exited with '. $status. PHP_EOL;
      }
    }
    }

    # 子进程执行的逻辑
    function excuteProcess($iPid, $iSeconds)
    {
    file_put_contents('./log/'.$iPid.'.log', $iPid.PHP_EOL, FILE_APPEND);
    sleep($iSeconds);
    }
    ?>

运行结果

    * Process 16163 was created, and Executed, and Sleep 11
    * Process 16164 was created, and Executed, and Sleep 21
    * Process 16165 was created, and Executed, and Sleep 24
    * Process 16166 was created, and Executed, and Sleep 27
    * Process 16167 was created, and Executed, and Sleep 8
    * Process 16168 was created, and Executed, and Sleep 14
    * Process 16169 was created, and Executed, and Sleep 14
    * Process 16170 was created, and Executed, and Sleep 26
    * Process 16171 was created, and Executed, and Sleep 20
    * Process 16172 was created, and Executed, and Sleep 21
    * Sub process: 16167 exited with 0
    * Sub process: 16163 exited with 0
    * Sub process: 16169 exited with 0
    * Sub process: 16168 exited with 0
    * Sub process: 16171 exited with 0
    * Sub process: 16164 exited with 0
    * Sub process: 16172 exited with 0
    * Sub process: 16165 exited with 0
    * Sub process: 16170 exited with 0
    * Sub process: 16166 exited with 0