<?php

$processes = array();

function addTask(&$processes, $callback){
	$pid = pcntl_fork();
        if ($pid < 0) {
            throw new RuntimeException("fork error");
        } elseif ($pid > 0) {
        } else {
            $pid = getmypid();
	    pcntl_signal(SIGTERM, 'sig_handler');
            call_user_func($callback);
            exit(0);
        }
	array_push($processes, $pid);
}

function sig_handler(){
	exit(0);
}

addTask($processes, array('test', 'run'));
addTask($processes, array('test', 'run'));
addTask($processes, array('test', 'run'));
addTask($processes, array('test', 'run'));
addTask($processes, array('test', 'run'));

$runnings = 1;
while($runnings > 0){
    foreach( $processes AS $key => $pid ){
        $res = pcntl_waitpid($pid, $status, WNOHANG | WUNTRACED);
        if ($res === -1) {
            $log = "pcntl_waitpid failed. the process maybe available";
	    error_log( $log );
        } elseif ($res === 0) {
		continue;
        } else {
            if (pcntl_wifsignaled($status)) {
                $term_signal = pcntl_wtermsig($status);
		$log = sprintf('子进程异常终止信号：%s, PID:%s', $term_signal, $pid);
		error_log( $log );
            }
            if (pcntl_wifstopped($status)) {
                $stop_signal = pcntl_wstopsig($status);
		$log = sprintf('子进程异常停止信号：%s, PID:%s', $stop_signal, $pid);
		error_log( $log );
            }
//	    for PHP 5 >= 5.3.4
//            if (pcntl_wifexited($status)) {
//                $errno = pcntl_wexitstatus($status);
//                $errmsg = pcntl_strerror($errno);
//		$log = sprintf('子进程异常退出：[%s]%s, PID:%s', $errno, $errmsg, $pid);
//		error_log( $log );
//            } else {
//                $errno = pcntl_get_last_error();
//                $errmsg = pcntl_strerror($errno);
//		$log = sprintf('子进程异常退出：[%s]%s, PID:%s', $errno, $errmsg, $pid);
//		error_log( $log );
//	    }
	    unset($processes[$key]);
	    $runnings = count($processes);
	}
    }
    usleep(100);
}

class test{
	function run($sec = 30){
		//$sec = mt_rand(1,$sec);
		sleep($sec);
		echo getmypid() . ':done => ' . $sec . PHP_EOL;
	}
}