PHP获得job队列、创建执行进程、等待结束

<?php defined('SYSPATH') OR die('No direct access allowed.');
class Controller_Jobs extends Controller_Base{

public function before(){
parent::before();
if(Request::$protocol != "cli"){
die("Only cli allowed!");
}
}

public function after(){
parent::after();
//do some cleaning tasks
}


private function _execJobCommand($joburi,$paras){

$php_exec = Kohana::config("picsou.php_exec");
$php_index = APPINDEX;
$command_args = array();
$command_args[] = $php_index;
$command_args[] = "--uri=".$joburi;
foreach ($paras as $para => $value){
$command_args[] = "--".$para."=".$value;
}

//var_dump($command_args);exit;
echo "exec commmand:".$php_exec."";
pcntl_exec($php_exec,$command_args);
}

/*
* Running jobs in queues
*/
public function action_run(){
$requestCount = 0;
while(true){
$sql = "select * from job_queue where status='1' and approved='1' order by id";
$jobs = DB::query(Database::SELECT,$sql)->execute()->as_array();
if($jobs){
foreach ($jobs as $job){
$requestCount ++;
//update the jobs status as running
DB::update('job_queue')->set(array('status'=>'2'))
->where('id','=',$job['id'])->execute();

$job_pid = pcntl_fork();
if($job_pid == -1){
die("Could not fork Child");
} else if($job_pid == 0 ){
$this->_execJobCommand($job['job_uri'],json_decode($job['paras'],true));
echo "finish Child";
exit(0);
//run jobs here
} else{
echo "Waiting for job";
ob_flush();
$child_pid = pcntl_waitpid($job_pid,$status, WUNTRACED);
echo "waitpid end:".$status."";
if($status == 0){
//job completed
DB::update('job_queue')->set(array('status'=>'999'))
->where('id','=',$job['id'])->execute();
echo "Child Finished";
ob_flush();
}else{
DB::update('job_queue')->set(array('status'=>'-1'))
->where('id','=',$job['id'])->execute();
echo "Child Failed";
ob_flush();
}
}
}
}
else{
if($requestCount >=10){
echo "Have a rest, I have processed 10 jobs";
exit;
}
//no job to run
//echo "No job";
ob_flush();
sleep(5);

}
}
}

}