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Update reentrantlock.md

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docs/java/concurrent/reentrantlock.md
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@ -218,6 +218,33 @@ private volatile int state;
![](https://p1.meituan.net/travelcube/b8b53a70984668bc68653efe9531573e78636.png) ![](https://p1.meituan.net/travelcube/b8b53a70984668bc68653efe9531573e78636.png)
> 🐛 修正: 图中的一处小错误，(AQS)CAS修改共享资源 State 成功之后应该是获取锁成功(非公平锁)。
>
> 对应的源码如下：
>
> ```java
> final boolean nonfairTryAcquire(int acquires) {
> final Thread current = Thread.currentThread();//获取当前线程
> int c = getState();
> if (c == 0) {
> if (compareAndSetState(0, acquires)) {//CAS抢锁
> setExclusiveOwnerThread(current);//设置当前线程为独占线程
> return true;//抢锁成功
> }
> }
> else if (current == getExclusiveOwnerThread()) {
> int nextc = c + acquires;
> if (nextc < 0) // overflow
> throw new Error("Maximum lock count exceeded");
> setState(nextc);
> return true;
> }
> return false;
> }
> ```
>
>
为了帮助大家理解 ReentrantLock 和 AQS 之间方法的交互过程，以非公平锁为例，我们将加锁和解锁的交互流程单独拎出来强调一下，以便于对后续内容的理解。 为了帮助大家理解 ReentrantLock 和 AQS 之间方法的交互过程，以非公平锁为例，我们将加锁和解锁的交互流程单独拎出来强调一下，以便于对后续内容的理解。
![](https://p1.meituan.net/travelcube/7aadb272069d871bdee8bf3a218eed8136919.png) ![](https://p1.meituan.net/travelcube/7aadb272069d871bdee8bf3a218eed8136919.png)