文件锁,memcache锁,SQL锁。推荐使用memcache锁。
<?php
class LockSystem
{
const LOCK_TYPE_DB = 'SQLLock';
const LOCK_TYPE_FILE = 'FileLock';
const LOCK_TYPE_MEMCACHE = 'MemcacheLock';
private $_lock = null;
private static $_supportLocks = array('FileLock', 'SQLLock', 'MemcacheLock');
public function __construct($type, $options = array())
{
if(false == empty($type))
{
$this->createLock($type, $options);
}
}
public function createLock($type, $options=array())
{
if (false == in_array($type, self::$_supportLocks))
{
throw new Exception("not support lock of ${type}");
}
$this->_lock = new $type($options);
}
public function getLock($key, $timeout = ILock::EXPIRE)
{
if (false == $this->_lock instanceof ILock)
{
throw new Exception('false == $this->_lock instanceof ILock');
}
$this->_lock->getLock($key, $timeout);
}
public function releaseLock($key)
{
if (false == $this->_lock instanceof ILock)
{
throw new Exception('false == $this->_lock instanceof ILock');
}
$this->_lock->releaseLock($key);
}
}
interface ILock
{
const EXPIRE = 5;
public function getLock($key, $timeout=self::EXPIRE);
public function releaseLock($key);
}
class FileLock implements ILock
{
private $_fp;
private $_single;
public function __construct($options)
{
if (isset($options['path']) && is_dir($options['path']))
{
$this->_lockPath = $options['path'].'/';
}
else
{
$this->_lockPath = '/tmp/';
}
$this->_single = isset($options['single'])?$options['single']:false;
}
public function getLock($key, $timeout=self::EXPIRE)
{
$startTime = Timer::getTimeStamp();
$file = md5(__FILE__.$key);
$this->fp = fopen($this->_lockPath.$file.'.lock', "w+");
if (true || $this->_single)
{
$op = LOCK_EX + LOCK_NB;
}
else
{
$op = LOCK_EX;
}
if (false == flock($this->fp, $op, $a))
{
throw new Exception('failed');
}
return true;
}
public function releaseLock($key)
{
flock($this->fp, LOCK_UN);
fclose($this->fp);
}
}
class SQLLock implements ILock
{
public function __construct($options)
{
$this->_db = new mysql();
}
public function getLock($key, $timeout=self::EXPIRE)
{
$sql = "SELECT GET_LOCK('".$key."', '".$timeout."')";
$res = $this->_db->query($sql);
return $res;
}
public function releaseLock($key)
{
$sql = "SELECT RELEASE_LOCK('".$key."')";
return $this->_db->query($sql);
}
}
class MemcacheLock implements ILock
{
public function __construct($options)
{
$this->memcache = new Memcache();
}
public function getLock($key, $timeout=self::EXPIRE)
{
$waitime = 20000;
$totalWaitime = 0;
$time = $timeout*1000000;
while ($totalWaitime < $time && false == $this->memcache->add($key, 1, $timeout))
{
usleep($waitime);
$totalWaitime += $waitime;
}
if ($totalWaitime >= $time)
throw new Exception('can not get lock for waiting '.$timeout.'s.');
}
public function releaseLock($key)
{
$this->memcache->delete($key);
}
}
try
{
//创建锁(推荐使用MemcacheLock)
$lockSystem = new LockSystem(LockSystem::LOCK_TYPE_MEMCACHE);
//获取锁
$lockKey = 'key';
$lockSystem->getLock($lockKey,8);
//业务逻辑
...
//释放锁
$lockSystem->releaseLock($lockKey);
}
catch (Exception $e)
{
//释放锁
$lockSystem->releaseLock($lockKey);
}
参考:
https://blog.csdn.net/clevercode/article/details/52493568
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