Java中的锁机制

Java中的锁机制：

1. API层面：Synchronized，AQS（CLH）: ReentrantLock，ReentrantReadWriteLock，StampedLock(Ordered RW locks)
2. JVM层面(Hotspot): SpinLock,Biased,Stack-Locked(轻量级锁), Inflated(重量级锁)
   • Neutral: Unlocked
   • Biased: Locked/Unlocked + Unshared
   • Stack-Locked: Locked + Shared but uncontended，The mark points to displaced mark word on the owner thread's stack.
   • Inflated: Locked/Unlocked + Shared and contended，Threads are blocked in monitorenter or wait().，The mark points to heavy-weight "objectmonitor" structure.

参考：
http://openjdk.java.net/groups/hotspot/docs/RuntimeOverview.html
AbstractQueuedLongSynchronizer,StampedLock源码
http://cs.rochester.edu/research/synchronization/pseudocode/ss.html