Table of Contents
Can we synchronize static method in Java?
Synchronized static methods are synchronized on the class object of the class the synchronized static method belongs to. Since only one class object exists in the Java VM per class, only one thread can execute inside a static synchronized method in the same class.
Can we synchronize private method in Java?
You don’t need to separately synchronize the private method if it is only called from synchronized methods.
Can we override Run method in Java?
Answer: Yes, we can override start() method of thread in Java, the same way we override any other methods. for example, In below, custom thread class MyThread, both start() method and run() method have been overridden.
Can we have multiple run methods in Java?
You can’t have two run() methods, because you (and the compiler) could not know which one to execute when calling obj. run() . Thread t1 = new Thread(new Runnable(){public void run(){…}}) By using inner class you can achieve multiple run methods in a single class.
Is volatile synchronized?
For the purposes of visibility, each access to a volatile field acts like half a synchronization. Under the new memory model, it is still true that volatile variables cannot be reordered with each other. The difference is that it is now no longer so easy to reorder normal field accesses around them.
Does synchronized method lock whole class?
Only one thread can execute inside a synchronized instance method. If more than one instance exist, then one thread at a time can execute inside a synchronized instance method per instance. And if synchronized method is static , then the method owner and that block’s monitor is the Class , so whole class gets locked.
Can Run method be overloaded?
Overloading of run() method is possible. But Thread class start() method can invoke no-argument method. The other overloaded method we have to call explicitly like a normal method call.
Can we override Thread run method?
We can override start/run method of Thread class because it is not final. But it is not recommended to override start() method, otherwise it ruins multi-threading concept.
Can we start two threads at a time?
No. After starting a thread, it can never be started again. If you does so, an IllegalThreadStateException is thrown. In such case, thread will run once but for second time, it will throw exception.
Why do we use synchronization in Java?
We need to synchronize the shared resources to ensure that at a time only one thread is able to access the shared resource. If an Object is shared by multiple threads then there is need of synchronization in order to avoid the Object’s state to be getting corrupted. Synchronization is needed when Object is mutable.
How do you synchronize a method in Java?
Synchronization in Java is achieved with the help of the keyword “synchronized”. This keyword can be used for methods or blocks or objects but cannot be used with classes and variables. A synchronized piece of code allows only one thread to access and modify it at a given time.
Is it possible to run two synchronized methods at the same time?
As we all know only one synchronized method can be run at the same time. So my questions is what if I declare the run () method as synchronized, and then run multi threads, is it possible for other thread to run the run () method?
What is the use of synchronized method in threading?
Synchronized method is used to lock an object for any shared resource. When a thread invokes a synchronized method, it automatically acquires the lock for that object and releases it when the thread completes its task. Output: 5 10 15 20 25 100 200 300 400 500.
Can two threads run the run() method at once?
You create two instance of Test as well as two threads run each, so it is impossible for other thread to run the run () method. Only if your two thread run with the same instance like this: You need a synchronized keyword for the run method. Thanks for contributing an answer to Stack Overflow!