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What does signalAll do in Java?
signalAll. Wakes up all waiting threads. If any threads are waiting on this condition then they are all woken up. Each thread must re-acquire the lock before it can return from await .
When should signalAll called?
When to use singal(), signallAll() in general: If you have a resource that has to be initialized before it can be used concurrently by all threads it makes sense to wake up all threads at once by calling signalAll().
How do you lock a method in Java?
lock() in the inner() method. A thread calling outer() will first lock the Lock instance. Then it will call inner() . Inside the inner() method the thread will again try to lock the Lock instance.
What is a conditional variable Java?
Condition variables are a mechanism that allow you to test that a particular condition holds true before allowing your method to proceed. In the case of your example there are two conditions, notFull and notEmpty .
How can we invoke all waiting threads?
Waiting threads to finish completely in Java
- Using join() method of Thread class.
- Using CountDownLatch.
- Using shutdown(), isTerminated() methods of Executors.
- Using invokeAll() method of ExecutorService.
- Using invokeAll() method of ExecutorCompletionService.
Why locks are better than synchronized?
Lock framework works like synchronized blocks except locks can be more sophisticated than Java’s synchronized blocks. Locks allow more flexible structuring of synchronized code. Only one thread is allowed to access only one method at any given point of time using a synchronized block.
What does await () do in java?
The await() method of the Java CyclicBarrier class is used to make the current thread waiting until all the parties have invoked await() method on this barrier or the specified waiting time elapses.
What is the difference between lock and ReentrantLock?
Lock is an interface. It defines a set of methods that all locks should have. ReentrantLock is a concrete class that implements the Lock interface. It implements all the methods defined in Lock , plus much more.
What is object lock in Java?
An object-level lock is a mechanism when we want to synchronize a non-static method or non-static code block such that only one thread will be able to execute the code block on a given instance of the class. Once the thread got the lock then it is allowed to execute any synchronized method on that object.
What are conditions java?
Java, like all other programming languages, is equipped with specific statements that allow us to check a condition and execute certain parts of code depending on whether the condition is true or false. Such statements are called conditional, and are a form of composite statement.
What is difference between wait () and sleep () method?
It tells the calling thread (a.k.a Current Thread) to wait until another thread invoke’s the notify() or notifyAll() method for this object, The thread waits until it reobtains the ownership of the monitor and Resume’s Execution….Difference between wait and sleep in Java.
| Wait() | Sleep() |
|---|---|
| Wait() is not a static method. | Sleep() is a static method. |
How can we avoid deadlock in Java?
How can we avoid a deadlock in Java?
- Avoid Nested Locks: A deadlock mainly happens when we give locks to multiple threads. Avoid giving a lock to multiple threads if we already have given to one.
- Avoid Unnecessary Locks: We can have a lock only those members which are required.
- Using Thread.