A brief introduction to PHP non-blocking mode, a brief introduction to PHP blocking_PHP tutorial

A brief introduction to PHP non-blocking mode, a brief introduction to PHP blocking

Non-blocking mode refers to the message mechanism that uses socket events, and the communication between the Server and Client is in an asynchronous state .

Let PHP no longer block. When PHP needs to complete some long-term processing as a back-end process, in order to quickly respond to page requests without making a judgment on the result return, the following measures can be taken:

1. If you are using FastCGI mode, using fastcgi_finish_request() can end the session immediately, but the PHP thread continues to run.

echo "program start.";
file_put_contents('log.txt','start-time:'.date('Y-m-d H:i:s'), FILE_APPEND);
fastcgi_finish_request();
sleep(1);
echo 'debug...';
file_put_contents('log.txt', 'start-proceed:'.date('Y-m-d H:i:s'), FILE_APPEND);
sleep(10);
file_put_contents('log.txt', 'end-time:'.date('Y-m-d H:i:s'), FILE_APPEND);

In the output of this example, you can see that the session returns after the output program start., so the debug output browser cannot receive it, but the log.txt file can fully receive the three completion times.

2. Use the non-blocking mode of fsockopen and cUrl to request another URL

$fp = fsockopen("www.example.com", 80, $errno, $errstr, 30);
if (!$fp) die('error fsockopen');
stream_set_blocking($fp,0);
$http = "GET /save.php / HTTP/1.1\r\n"; 
$http .= "Host: www.example.com\r\n"; 
$http .= "Connection: Close\r\n\r\n";
fwrite($fp,$http);
fclose($fp);

Use curl_multi_* functions in cURL to send asynchronous requests

$cmh = curl_multi_init();
$ch1 = curl_init();
curl_setopt($ch1, CURLOPT_URL, "http://localhost:6666/child.php");
curl_multi_add_handle($cmh, $ch1);
curl_multi_exec($cmh, $active);
echo "End\n";

3. Use Gearman and Swoole extensions

Gearman is a distributed asynchronous processing framework with PHP extensions that can handle large batches of asynchronous tasks;
Swoole is very popular recently. It has many asynchronous methods and is easy to use. (Note from Chenyuan: It claims to redefine PHP and completely destroy NodeJS. Although the Swoole tool is good, I feel that the extension itself is not comparable to NodeJS)

4. Use redis and other caches and queues to write data to the cache, and use background scheduled tasks to achieve asynchronous processing of data.

This method should be very common in common high-traffic architectures

5. In extreme cases, system commands can be called and data can be passed to background tasks for execution. Personally, I feel it is not very efficient.

$cmd = 'nohup php ./processd.php $someVar >/dev/null &';
`$cmd`

6. I don’t understand the gringo’s ultimate move, it’s natively supported by php

http://nikic.github.io/2012/12/22/Cooperative-multitasking-using-coroutines-in-PHP.html

7. Install the pcntl extension and use pcntl_fork to generate a child process to execute tasks asynchronously. Personally, I think it is the most convenient, but it is also prone to zombie process .

if (($pid = pcntl_fork()) == 0) {
child_func(); //子进程函数，主进程运行
} else {
father_func(); //主进程函数
}
echo "Process " . getmypid() . " get to the end.\n";
function father_func() {
echo "Father pid is " . getmypid() . "\n";
}
function child_func() {
sleep(6);
echo "Child process exit pid is " . getmypid() . "\n";
exit(0);
}

The above content is the PHP non-blocking mode introduced by the editor. I hope it will be helpful to everyone!