phplock (php process lock) v1.0 beta1_PHP tutorial-PHP Tutorial-php.cn

phplock (php process lock) v1.0 beta1_PHP tutorial

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Release： 2016-07-21 15:43:00

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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 (); 
} 
?> 
 