The example in this article describes the implementation method of multi-thread concurrency in PHP. Share it with everyone for your reference, the details are as follows:

Multi-threading in Java is a new thread thing. PHP relies on Apache and there is a multi-threading method at the bottom of Linux.

Here is how to simulate PHP concurrency if you cannot control the Apache server

<?php
if(function_exists(&#39;date_default_timezone_set&#39;)) {
  date_default_timezone_set(&#39;PRC&#39;);
}
function a()
{
 $time = time();
 sleep(3);
 $fp = fopen(&#39;result_a&#39;.$time.&#39;.log&#39;, &#39;w&#39;);
 fputs($fp, &#39;Set in &#39; . Date(&#39;h:i:s&#39;, time()) . (double)microtime() . "rn");
 fclose($fp);
}
function b()
{
 $time = time();
 sleep(3);
 $fp = fopen(&#39;result_b&#39;.$time.&#39;.log&#39;, &#39;w&#39;);
 fputs($fp, &#39;Set in &#39; . Date(&#39;h:i:s&#39;, time()) . (double)microtime() . "rn");
 fclose($fp);
}
if(!isset($_GET[&#39;act&#39;])) $_GET[&#39;act&#39;] = &#39;a&#39;;
if($_GET[&#39;act&#39;] == &#39;a&#39;)
{
 a();
}
else if($_GET[&#39;act&#39;] == &#39;b&#39;) b();
?>

The above code writes a file locally.

If you visit localhost/a.php and open two browser tabs at the same time as quickly as possible, you will find that the difference in creation time of the two files is 3 seconds

But if you visit localhost/a.php?act=b another one Visit /a.php?act=a and you will find that the two files were created at almost the same time.

For apache, the same URL means a thread (or process), but different URLs mean concurrency.

If there is a download action inside php

function runThread()
{
 down("http://localhost/test/a.php?act=a");
}
if($_GET['act'] == 'run')
{
 echo 'start:';
 runThread();
 echo ' End';
}

http://localhost/test/a.php?act=run

http://localhost/test/a.php?act=run&s=2

As long as the host If the accessed URLs are different, they are considered to be different processes, which means concurrency. The file creation time is not 3 seconds

Friends who have a local Linux server can also use Linux to simulate concurrency

<?php
for ($i=0;$i<10;$i++) {
echo $i;
sleep(5);
}
?>

Save the above as test.php, and then write a SHELL code

#!/bin/bash
for i in 1 2 3 4 5 6 7 8 9 10
do
php -q test.php &
done

More PHP will convert the entire website For a summary of methods for generating pure static HTML web pages, please pay attention to the PHP Chinese website for related articles!