phplock (php process lock) v1.0 beta1_PHP tutorial

In web development, we often cache time-consuming operations of our database, but there may be a trap. At the moment when the cache fails, a large number of accesses get cache failure indications, and all go to the backend to query the database, resulting in a large number of databases at the same time. Time-consuming queries may cause problems such as database downtime. This problem is deeply hidden and difficult to find. This project is mainly used to solve the inter-process lock problem of PHP.
Example:

Copy code The code is as follows:

/**
* Test example, open two pages at the same time, you can find the code that only one page can always enter the lock range at the same time
* @link http://code.google.com/p/phplock/
* @author sunli
* @svnversion $Id: test.php 2 2009-11-24 07:14:27Z sunli1223 $
* @version v1.0 beta1
* @license Apache License Version 2.0
* @copyright sunli1223@gmail.com
*/
require 'class.phplock.php';
$lock = new PHPLock ( 'lock/', 'lockname' );
$lock->startLock ();
$lock ->startLock ();
//process code
echo "enter lock
rn";
ob_end_flush();
flush ();
ob_flush();
sleep (5); //Sleep for 20 seconds, simulate concurrent operations
echo "Execution completed
rn";
$lock-> ;unlock ();
$lock->endLock ();
echo "Release lock completed
rn";
/**
* cache operation
*
* @return $array
*/
function getCache ($key) {
return $cache;
}
/**
* Set cache
*
* @param string $key
* @param array $value
*/
function setCache($key,$value) {

}
$cache=getCache($key);
if (! $cache) {
//The cache does not exist, start locking
$lock = new PHPLock ('lock/', $key);
$lock->startLock ();
$lock->startLock ();
//Try to determine whether there is data in the cache. There may have been access to rebuild the cache, so there is no need to query the database again
$cache=getCache();
if(!$cache){
//Database query operation, the code is omitted
$data=$dbdata;
setCache($key,$data );
}
//Release lock
$lock->unlock ();
$lock->endLock ();
}
?>

Recommended related articles
Analysis and research on PHP process locking problem

http://www.bkjia.com/PHPjc/320818.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/320818.htmlTechArticleIn web development, we often cache time-consuming operations of our database, but there may be a trap in caching At the moment of failure, a large number of accesses were marked as cache invalid, all...