cn.ponfee.scheduler.common.lock

类 RedisLock

java.lang.Object

cn.ponfee.scheduler.common.lock.RedisLock

所有已实现的接口:

Serializable, Lock

public class RedisLock
extends Object
implements Lock, Serializable

Distributes lock based redis(unlock使用redis lua script)

 class X {
   public void m() {
     Lock lock = new RedisLock(redisTemplate, "lockKey", 100);
     lock.lock();  // block until acquire lock or timeout
     try {
       // ... method body
     } finally {
       lock.unlock()
     }
   }
 }

 class Y {
   public void m() {
     Lock lock = new RedisLock(redisTemplate, "lockKey", 100);
     if (!lock.tryLock()) return;
     try {
       // ... method body
     } finally {
       lock.unlock();
     }
   }
 }

 class Z {
   public void m() {
     Lock lock = new RedisLock(redisTemplate, "lockKey", 100);
     // auto timeout release lock
     if (!lock.tryLock(100, TimeUnit.MILLISECONDS)) return;
     try {
       // ... method body
     } finally {
       lock.unlock();
     }
   }
 }
 

作者:

Ponfee

另请参阅:

better implementation: redisson, 序列化表格

构造器概要

构造器

构造器和说明
RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate, String lockKey)
RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate, String lockKey, int timeoutMillis)
RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate, String lockKey, int timeoutMillis, int sleepMillis) Constructor

方法概要

限定符和类型	方法和说明
static boolean	exceptionContainsNoScriptError(Throwable e)
void	funlock() Force unlock
boolean	isHeldByCurrentThread() 当前线程是否持有锁 {@code class X { Lock lock = new RedisLock(redisTemplate, "lockKey", 100); // ...
boolean	isLocked() 是否已锁（任何线程）
void	lock() 等待锁直到获取(non interrupt)
void	lockInterruptibly() 等待锁直到获取成功或抛出InterruptedException异常
Condition	newCondition()
boolean	tryLock() 尝试获取锁，成功返回true，失败返回false
boolean	tryLock(long timeout, TimeUnit unit) 尝试获取锁，成功返回true，失败返回false 线程中断则抛出interrupted异常
void	unlock() 释放锁

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

RedisLock

public RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate,
                 String lockKey)

RedisLock

public RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate,
                 String lockKey,
                 int timeoutMillis)

RedisLock

public RedisLock(org.springframework.data.redis.core.RedisTemplate<?,?> redisTemplate,
                 String lockKey,
                 int timeoutMillis,
                 int sleepMillis)

Constructor

参数:

redisTemplate - spring redis template

lockKey - the lock key

timeoutMillis - lock timeout millis seconds(prevent deadlock)

sleepMillis - wait sleep millis seconds

方法详细资料

lock

public void lock()

等待锁直到获取(non interrupt)

指定者:

lock 在接口中 Lock

lockInterruptibly

public void lockInterruptibly()
                       throws InterruptedException

等待锁直到获取成功或抛出InterruptedException异常

指定者:

lockInterruptibly 在接口中 Lock

抛出:

InterruptedException - if call Thread#interrupt

tryLock

public boolean tryLock()

尝试获取锁，成功返回true，失败返回false

指定者:

tryLock 在接口中 Lock

返回:

if true get lock successfully

tryLock

public boolean tryLock(long timeout,
                       @Nonnull
                       TimeUnit unit)
                throws InterruptedException

尝试获取锁，成功返回true，失败返回false
线程中断则抛出interrupted异常

指定者:

tryLock 在接口中 Lock

参数:

timeout - the timeout value

unit - the timeout unit

返回:

true lock successfully

抛出:

InterruptedException - if interrupted

unlock

public void unlock()

释放锁

指定者:

unlock 在接口中 Lock

newCondition

public Condition newCondition()

指定者:

newCondition 在接口中 Lock

isHeldByCurrentThread

public boolean isHeldByCurrentThread()

当前线程是否持有锁

  
     class X {
       Lock lock = new RedisLock(redisTemplate, "lockKey", 100);
       // ...
       public void m() {
         assert !lock.isHeldByCurrentThread();
         lock.lock();
         try {
             // ... method body
         } finally {
             lock.unlock();
         }
       }
     }
  
 

返回:

if true the current thread held locked

isLocked

public boolean isLocked()

是否已锁（任何线程）

返回:

true is locked

funlock

public void funlock()

Force unlock

exceptionContainsNoScriptError

public static boolean exceptionContainsNoScriptError(Throwable e)