Use Memache as process lock

<?php

// 使用Memache 作为进程锁 

class lock_processlock{
	
	
	// key 的前缀
	protected $sLockKeyPre;
	// 重试间隔
    protected $iLockRetryInterval;
	//重试次数 
    protected $iLockRetryCount;
	//锁的过期时间
    protected $iLockCacheTimeout;
    // 锁过期后的回调函数
    protected $onLockTimeoutFunc;
	// memache 的实例
    protected $oMemcache;
	// 存储memcache失败后重试次数 
    protected $iMemcacheRetryCount;
	
	
	
	
	  public function __construct ($onLockTimeoutFunc=NULL) {
        $aLockConfig = get_config(&#39;&#39;, &#39;lock&#39;);
        $this->sLockKeyPre = self::LOCK_KEY_PRE;
        $this->iLockRetryInterval = self::LOCK_RETRY_INTERVAL;
        $this->iLockRetryCount =self::LOCK_RETRY_COUNT;
        $this->iLockCacheTimeout = self::LOCK_CACHE_TIMEOUT;
        $this->iMemcacheRetryCount = self::LOCK_CACHE_TIMEOUT;
		if(!$onLockTimeoutFunc){
			// 如果加锁不成功则调用回调函数,如果没有回调函数,使用本类中所带的 
			$onLockTimeoutFunc ='onLockTimeout' ; 
		}
        $this->onLockTimeoutFunc = $onLockTimeoutFunc;
    }
	
	
	/**
	连接memcache 服务器 
	*/
	public  function connect() {
		if (! isset ( $this->oMemcache )) {
			$this->oMemcache = new Memcache ();
			$this->oMemcache->connect ( '127.0.0.1', 11211 );
		}
		return $this->oMemcache;
	}
	
	
	/*
	向MeMcache中添加 key
	*/
	public addMemcache($sKey, $sValue, $iTimeout){
		
		for($i= 0 ; $i<$this->iMemcacheRetryCount){
			$bRes = $this->oMemcache->add($sKey, $sValue, $iTimeout);
			if($bRes){
				return true ; 
			}
				// 如果加锁不成功,sleep 之后,从新加锁
			usleep($this->iLockRetryInterval*1000);
			
		}
		return  false ;  
		
	}
	
	
	/*
	加锁 
	*/
	public function lock($sLockID){
		
		$oMemcache =   $this->connect();
	    $sKey = $this->sLockKeyPre . $sLockID;
		
		// 加锁如果不成功可以多试几次 
		
		for($i = 0 ; $i <$this->iLockRetryCount ; $i++){
			
			// 这里设置value 的值可以随便设置 
			if($this->addMemcache($sKey,'1',$this->iLockCacheTimeout)){
				return true ; 
			}
			
			// 如果加锁不成功,sleep 之后,从新加锁
			usleep($this->iLockRetryInterval*1000);
			
		}
		
		// 若还不成功,则加锁失败,调用回调函数,.也就是失败后需要处理的操作 
		if(is_callable($this->onLockTimeoutFunc)){
			// 调用函数 
			call_user_func($this->onLockTimeoutFunc); 
		}
		
	}
	
	
	/*
	解锁操作 
	*/
	public function unlock($sLockID){
		
		$oMemcache =   $this->connect();
	    $sKey = $this->sLockKeyPre . $sLockID;
		// 删除key
		return $this->oMemcache->delete($sKey);
		
	}
	
	
	/**
	如果加锁不成功,则执行如下操作 
	*/
	 public function onLockTimeout(){
		 
		 echo ("加锁超时");
	 }
     
}



// 应用实例 

  $oLock = new lock_processlock();
  $lockResource = "test";
  // 加锁
  $oLock->lock($lockResource);
  // 解锁
  $oLock->unlock($lockResource);

The above has introduced the use of Memache as a process lock, including aspects of the process. I hope it will be helpful to friends who are interested in PHP tutorials.