> 定时器任务功能类似于Linux下的crontab;因为使用了开源的[cron-expression](https://github.com/dragonmantank/cron-expression)来解析运行周期,所以zcswoole目前最小粒度只支持到分钟;swoole可以实现毫秒级别的定时器,所以如果你需要更小粒度的定时器需求,那么需要自己实现解析运行周期的方法;
#### 原理:
zcswoole的定时器为1秒轮询所有任务,将到期的任务丢到task进程处理,task进程不会影响工作进程,所以理论上误差不会很大
#### 创建任务表:
```sql
DROP TABLE IF EXISTS contrab;
CREATE TABLE contrab (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`timer` VARCHAR(255)
CHARACTER SET utf8
COLLATE utf8_general_ci NOT NULL
COMMENT '定时周期',
`command` VARCHAR(255)
CHARACTER SET utf8
COLLATE utf8_general_ci NOT NULL
COMMENT '命令',
`remark` TEXT CHARACTER SET utf8
COLLATE utf8_general_ci NOT NULL
COMMENT '备注',
`create_time` DATETIME DEFAULT NULL,
`status` TINYINT(2) NOT NULL DEFAULT '0'
COMMENT '0开启,1关闭',
PRIMARY KEY (`id`)
)
ENGINE = InnoDB
CHARSET = utf8
COLLATE utf8_general_ci
COMMENT = '定时器';
```
#### 代码:
zcswoole在http服务已内置定时器功能,在http服务启动时,会在第一个进程设置一个定时器,每秒轮询所有任务
```php
/**
* http服务,继承zcswoole的httpServer服务后,覆盖父类方法可以扩展自己功能
* Class HttpCommand
* @package command
*/
class HttpCommand extends HttpServerCommand
{
// demo,为http服务添加一个定时器功能,重写父类onEvent方法
public function onEvent()
{
parent::onEvent();
$this->server->on('receive', [$this, 'receive']);
$this->server->on('task', [$this, 'task']);
$this->server->on('finish', [$this, 'finish']);
}
/**
* 开始进程,重写父类workerStart方法
* @param $server
* @param $workerID
*/
public function workerStart($server, $workerID)
{
// 为第一个进程安装定时器
if (!$this->server->taskworker && $workerID == 0) {
Console::msg('crontab task start......');
swoole_timer_tick(1000, function(){
$records = MysqliDB::instance()->where('status', 0)->get('crontab');
foreach ($records as $record) {
$nextTime = CronExpression::factory($record['timer'])->getNextRunDate()->getTimestamp() - 1;
if (time() == $nextTime) {
$this->server->task($record['command']);
} /*else {
Console::msg("no run; next time is ".$nextTime.", now time is ". time());
}*/
}
});
}
}
/**
* 处理任务
* @param Server $server
* @param $taskID
* @param $workerID
* @param $data
* @return string
*/
public function task(Server $server, $taskID, $workerID, $data)
{
exec($data);
return $data . 'success';
}
/**
* 结束任务回调
* @param Server $server
* @param $taskID
* @param $data
*/
public function finish(Server $server, $taskID, $data)
{
Console::success('has run ' . $data);
}
}
```
#### 效果:
- 任务管理页面:
- 后台执行:
