php多进程pcntl学习-僵尸进程

<?php
$ppid = getmygid();
$pid = pcntl_fork();
if ($pid == -1){
die(‘fork failed‘);
}else if($pid == 0){
$mypid = getmygid();
echo ‘I am child process. My PID is ‘ . $mypid . ‘ and my father is‘,$ppid.PHP_EOL;
exit(); //关闭子进程 ,需要配合pcntl_wait使用 , 否则通过ps aux | grep php - >[php] <defunct> 僵尸进程
}else{
echo ‘Oh my god! I am a father now! My child is‘. $pid . ‘ and mine is ‘ . $ppid . PHP_EOL;
//pcntl_wait($status); //回收子进程,避免僵尸进程
}
//使主进程挂起
sleep(100);