Research on Asynchronous Operations in PHP_PHP Tutorial

1. Why does PHP need asynchronous operations?

Generally speaking, PHP is suitable for short-term tasks such as web page display. If you perform time-consuming operations such as resizing images, importing big data, sending EDM, SMS, etc. in batches, it is easy to cause operation timeout. Condition. You can say that I can set an infinite timeout, etc. You also need to know that PHP has a working mode which is fastcgi. PHP does not timeout indefinitely, which does not mean that fastcgi will not timeout... If you still want fastcgi to never timeout, I It is recommended that you discuss it with your operation and maintenance personnel...

At this time, the asynchronous operation comes into play. Since it is a non-blocking operation, the operation will return immediately, and then work slowly in the background. It doesn’t matter whether it times out or not, I’m not working under the current process/thread. Look, isn’t it beautiful, but actually it’s also a trap...

2. Can PHP implement asynchronous operations?

The answer is yes, but various pure PHP implementations on the Internet are a bit awkward. Socket mode, suspended process mode, and some even directly fork the process. Very good, all kinds of gods show their magical powers. If the operation and maintenance personnel see it, they will definitely attack you. It would be strange if they don’t kill the web server...

Is there any other better way to implement this asynchronous operation? Yes, now we only have to think about how to enable plug-ins. Check the mainstream plug-in solutions of PECL. There are a bunch of ××MQ (message queue). Among them, there is a plug-in for task distribution that comes into our sight. Gearman (actually this guy is the corner, I won’t introduce it in detail, click to connect See introduction).

3. Why choose Gearman?

If nothing else, let’s just say that it has many clients and supports clients in many languages. You can use most of the languages ​​you like to write workers. Personally, I am very annoyed by the language debate. You can use Shenma to write workers as you like. There is data persistence support (that is, the queue is saved to the database medium, so failure recovery is easy), and there is cluster support (in fact, many ××MQ have these functions). There are extensions on PECL, and there are also extensions implemented in pure PHP. Anyway, this Gearman has lived for a long time, and all the miscellaneous problems have been basically solved.

4. Basic idea

With the Gearman plug-in, it is much easier. It means sending a task to gearman, sending out the executed task, and then waiting for the worker to call the PHP cli to run our php code.

I just wrote a python worker (don’t ask me why I use python, 1. I know python, 2. I don’t need to install runtime under Linux). You can write a PHP worker based on your own ideas, but, I don't really trust workers running PHP. For other languages, you can try implementing a worker using java, node.js or other languages. Friends who are interested in writing workers in Golang can contact me.

phpasync_worker_py

Sorry, there are no comments in it. A configuration file and a py script. The basic function is to analyze the calling parameters and then call the PHP Cli, that's it. To make the py script run, please install the python gearman module yourself.

Then go to the PHP part and write the test code first:

Copy code The code is as follows:

require_once 'PHPAsyncClient.php';
date_default_timezone_set('Asia/Shanghai');

class AsyncTest {

    const
        LOG_FILE = '/debug.log';

    static public function run() {
        if (PHPAsyncClient::in_callback(__FILE__)) {
            self::log('php Async callback');
            PHPAsyncClient::parse();
            return;
        }
        if (PHPAsyncClient::is_main(__FILE__)) {
            self::log('main run');
            $async_call = PHPAsyncClient::getInstance();
            $async_call->AsyncCall('AsyncTest', 'callback', array(
                'content' => 'Hello World!!!',
            ), array(
                'class' => 'AsyncTest',
                'method' => 'callback',
                'params' => array(
                    'content' => 'Hello Callback!',
                ),
            ), __FILE__);
            return;
        }
    }

    static public function callback($args) {
        self::log('AsyncTest callback run');
        self::log('AsyncTest callback args:'.print_r($args, true));
    }

    static public function log($content) {
        $fullname = dirname(__FILE__).self::LOG_FILE;
        $content = date('[Y-m-d H:i:s]').$content."n";
        file_put_contents($fullname, $content, FILE_APPEND);
    }
}
AsyncTest::run();

就3个静态方法，一个是用于调试的log方法，其他都是字面意思。这个例子是对这种调用方式有个初步印象。然后直接上PHP的所有源码：

php_async.zip

然后应该会有很多人会说，win下安装不了gearman……所以我把java版的gearman server也放上去吧。

java-gearman-service-0.6.6.zip

5.结论

经过以上配置犀牛一样大的家伙后（要装一个Gearman，还要跑个Py脚本），我们基本上就使PHP拥有了异步调用功能，当然其中还有一个状态维护神马的要自己去实现。所以发现，其实这个方案不咋样，太复杂了。还是使用一些web service的方式去做web callback会好点（问题是web callback一样会超时……），这个请留意后续。  

为防止上面的代码无法下载，脚本之家特打包下载

原文链接：http://my.oschina.net/wakanoc/blog/101789

http://www.bkjia.com/PHPjc/326466.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/326466.htmlTechArticle1.为啥PHP需要异步操作？ 一般来说PHP适用的场合是web页面展示等耗时比较短的任务，如果对于比较花时间的操作如resize图片、大数据导入、...