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Java synchronized methods: lock on object or class
Please Explain How Java synchronized work with static method ? Some one has said that it is done by its Class Object but they don't say how the lock is done with that.
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Instead of locking on the instance, it locks on the object which epresents the class. Google for more details. – Peter Lawrey Jun 19 '12 at 09:18
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1http://stackoverflow.com/questions/578904/how-do-synchronized-static-methods-work-in-java – epoch Jun 19 '12 at 09:19
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You always synchronize on a monitor object. Every Java object can be used here.
With a synchronized block, you can specify that object directly.
synchronized (something){
}
With a synchronized method, it synchronizes on the object instance itself (on this), so it is identical to:
synchronized (this) {
}
With a synchronized static method, it synchronizes on the class object, just like "some one has said".
synchronized (ThisClass.class){
}
The mechanism is always the same: Only one thread can hold the lock at the same time, others have to wait.
Thilo
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No , I ment that static method and instance method. So how both method synchronized block when they access. Specially static method. What is the loked concept when it access. – Harsha Jun 19 '12 at 10:37
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`static synchronized void theMethod(){}` does the same thing as `static void theMethod(){ synchronized(ThisClass.class){} }` – Thilo Jun 19 '12 at 12:16