Friendica Communications Platform (please note that this is a clone of the repository at github, issues are handled there) https://friendi.ca
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

142 lines
3.3 KiB

<?php
namespace Friendica\Core;
/**
* @file src/Core/Lock.php
* @brief Functions for preventing parallel execution of functions
*/
use Friendica\Core\Logger;
use Friendica\Core\Cache\CacheDriverFactory;
use Friendica\Core\Cache\IMemoryCacheDriver;
/**
* @brief This class contain Functions for preventing parallel execution of functions
*/
class Lock
{
/**
* @var Lock\ILockDriver;
*/
static $driver = null;
public static function init()
{
$lock_driver = Config::get('system', 'lock_driver', 'default');
try {
switch ($lock_driver) {
case 'memcache':
case 'memcached':
case 'redis':
$cache_driver = CacheDriverFactory::create($lock_driver);
if ($cache_driver instanceof IMemoryCacheDriver) {
self::$driver = new Lock\CacheLockDriver($cache_driver);
}
break;
case 'database':
self::$driver = new Lock\DatabaseLockDriver();
break;
case 'semaphore':
self::$driver = new Lock\SemaphoreLockDriver();
break;
default:
self::useAutoDriver();
}
} catch (\Exception $exception) {
Logger::log('Driver \'' . $lock_driver . '\' failed - Fallback to \'useAutoDriver()\'');
self::useAutoDriver();
}
}
/**
* @brief This method tries to find the best - local - locking method for Friendica
*
* The following sequence will be tried:
* 1. Semaphore Locking
* 2. Cache Locking
* 3. Database Locking
*
*/
private static function useAutoDriver() {
// 1. Try to use Semaphores for - local - locking
if (function_exists('sem_get')) {
try {
self::$driver = new Lock\SemaphoreLockDriver();
return;
} catch (\Exception $exception) {
Logger::log('Using Semaphore driver for locking failed: ' . $exception->getMessage());
}
}
// 2. Try to use Cache Locking (don't use the DB-Cache Locking because it works different!)
$cache_driver = Config::get('system', 'cache_driver', 'database');
if ($cache_driver != 'database') {
try {
$lock_driver = CacheDriverFactory::create($cache_driver);
if ($lock_driver instanceof IMemoryCacheDriver) {
self::$driver = new Lock\CacheLockDriver($lock_driver);
}
return;
} catch (\Exception $exception) {
Logger::log('Using Cache driver for locking failed: ' . $exception->getMessage());
}
}
// 3. Use Database Locking as a Fallback
self::$driver = new Lock\DatabaseLockDriver();
}
/**
* Returns the current cache driver
*
* @return Lock\ILockDriver;
*/
private static function getDriver()
{
if (self::$driver === null) {
self::init();
}
return self::$driver;
}
/**
* @brief Acquires a lock for a given name
*
* @param string $key Name of the lock
* @param integer $timeout Seconds until we give up
* @param integer $ttl The Lock lifespan, must be one of the Cache constants
*
* @return boolean Was the lock successful?
*/
public static function acquire($key, $timeout = 120, $ttl = Cache::FIVE_MINUTES)
{
return self::getDriver()->acquireLock($key, $timeout, $ttl);
}
/**
* @brief Releases a lock if it was set by us
*
* @param string $key Name of the lock
* @return void
*/
public static function release($key)
{
self::getDriver()->releaseLock($key);
}
/**
* @brief Releases all lock that were set by us
* @return void
*/
public static function releaseAll()
{
self::getDriver()->releaseAll();
}
}