一个简单的php守护进程代码示例

工作中同事需要做一个简单的工作进程,需要在进程结束时不能被硬生生的掐断当前正在执行的工作流程,需要等一个处理流程跑完了再结束,所以这时候就需要用到pcntl的信号量来工作了,主要的设计思路:

  1. 捕获系统发给进程的中断的信号量
  2. 在handler代码中设置标志位变量
  3. 在一个业务循环处理完成之后判断标志位变量,如果接收到过终止请求,则跳出整个工作循环。 主要的处理逻辑:
  • 注册绑定函数:

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    protected function regist_sig_handler()
    {
    declare(ticks = 1);
    pcntl_signal(SIGTERM, [$this, 'sig_handler']);
    pcntl_signal(SIGHUP, [$this, 'sig_handler']);
    pcntl_signal(SIGINT, [$this, 'sig_handler']);
    }

  • 在函数中设置标志位:

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protected function sig_handler($signo)
{
switch ($signo) {
case SIGTERM:
case SIGHUP:
case SIGINT:
self::$_MYDAEMON_SHOULD_STOP = true;
// ...
break;
}
}

  • 构建退出处理函数

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    protected function shouldStop()
    {
    if (self::$_MYDAEMON_SHOULD_STOP) {
    // before exit staff code
    // ...
    return true;
    }
    return false;
    }

  • 在主循环中一次处理完成后判断是否要终止退出

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    while (true) {
    if ($this->shouldStop()) {
    break;
    }
    try {
    $jobStatusInfo = $this->execute([]);
    } catch (Exception $ex) {
    $this->log($ex->getMessage());
    }
    usleep(10);
    }

附上完整代码(loop是示例需要长时间处理的业务逻辑,memoryusage超限也会退出,外部可以由supervisor/daemontools等进程监控程序控制)

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#!/usr/bin/env php
<?php
/**
* Description
*
* @project mydevkit
* @package mydevkit
* @author nickfan <nickfan81@gmail.com>
* @link http://www.axiong.me
* @version $Id$
* @lastmodified: 2015-07-08 09:37
*
*/
@set_time_limit(0);
class myDaemon
{
const DEBUG = true;
protected static $_MYDAEMON_SHOULD_STOP = false;
public static $memLimit = 5242880;
private $loop = 10;
protected $logpath = '';
public function __construct($option = [])
{
$option += [
'loop' => 10,
'memLimit' => 5242880,
'logpath' => '/tmp/daemon_kill.log',
];
$this->loop = $option['loop'];
$this->logpath = $option['logpath'];
self::$memLimit = $option['memLimit'];
$this->regist_sig_handler();
}
public function __destruct()
{
$this->log('worker progress ending...');
}
protected function regist_sig_handler()
{
declare(ticks = 1);
pcntl_signal(SIGTERM, [$this, 'sig_handler']);
pcntl_signal(SIGHUP, [$this, 'sig_handler']);
pcntl_signal(SIGINT, [$this, 'sig_handler']);
}
protected function sig_handler($signo)
{
switch ($signo) {
case SIGTERM:
case SIGHUP:
case SIGINT:
self::$_MYDAEMON_SHOULD_STOP = true;
$signoStr = '';
if ($signo == SIGTERM) {
$signoStr = 'SIGTERM';
} elseif ($signo == SIGHUP) {
$signoStr = 'SIGHUP';
} elseif ($signo == SIGINT) {
$signoStr = 'SIGINT';
}
$content = date('Y-m-d H:i:s') . ' ' . $signoStr . PHP_EOL;
file_put_contents($this->logpath, $content, FILE_APPEND);
break;
}
}
protected function shouldStop()
{
if (self::$_MYDAEMON_SHOULD_STOP) {
// before exit staff code
// ...
return true;
}
return false;
}
protected function log()
{
$args = func_get_args();
$retstr = date('[Y-m-d H:i:s] ') . implode(' ', $args) . PHP_EOL;
if (self::DEBUG == true) {
echo $retstr;
} else {
return $retstr;
}
}
public function execute($data = [])
{
$this->log('[EXECUTE] process lot of data.');
for ($i = 0; $i < $this->loop; $i++) {
$this->log('step:' . ($i + 1));
sleep(1);
}
return rand(1, $this->loop);
}
public function run()
{
$this->log('[RUN] worker starting to run ...');
while (true) {
if ($this->shouldStop()) {
break;
}
$this->log('processJobData Start ...');
try {
$jobStatusInfo = $this->execute([]);
$this->log('processJobData end with: ' . var_export($jobStatusInfo, true));
unset($jobStatusInfo);
} catch (Exception $ex) {
$this->log($ex->getMessage());
}
$memory = memory_get_usage();
$this->log('memory usage:' . sprintf('%.2fMB', round($memory / 1048576, 2)));
if ($memory > self::$memLimit) {
$this->log('exiting run due to memory limit');
exit;
}
//sleep(1);
usleep(10);
}
$this->log('[RUN] worker run quit.');
}
}
$gotMyParam = 10;
if (isset($argv[1])) {
$gotMyParam = intval(trim(strip_tags($argv[1])));
}
$worker = new myDaemon(['loop' => $gotMyParam, 'memLimit' => 1048576 * 128,]);
$worker->run();

也可以到我的coding上下载:

https://coding.net/u/nickfan/p/mydevkit/git/blob/master/bin/daemon

测试:

在class代码中的构造函数中注释掉

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//$this->regist_sig_handler();

运行daemon代码,在执行execute的for循环时ctrl+c或者用 kill 杀死当前进程

Snip20150708_1

进程直接结束,没有执行完execute的一个完整流程就直接退出了,

把注释去掉重新执行daemon代码:

Snip20150708_2

在执行过程中按ctrl+c或者kill命令杀死前进程

观察daemon运行的结果是直到整个execute循环执行完了以后才退出程序的

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