Table of Contents
When to Use wait and notify in Java?
The wait() method causes the current thread to wait until another thread invokes the notify() or notifyAll() methods for that object. The notify() method wakes up a single thread that is waiting on that object’s monitor. The notifyAll() method wakes up all threads that are waiting on that object’s monitor.
What is thread wait in Java?
wait() causes current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0). The current thread must own this object’s monitor.
What is illegal thread state exception?
java.lang.IllegalThreadStateException. Thrown to indicate that a thread is not in an appropriate state for the requested operation. See, for example, the suspend and resume methods in class Thread .
What is difference between wait and sleep in Java?
Wait() method releases lock during Synchronization. Sleep() method does not release the lock on object during Synchronization. Wait() should be called only from Synchronized context. There is no need to call sleep() from Synchronized context.
What happens when notifyAll is called?
Calling notify() or notifyAll() methods issues a notification to a single or multiple threads that a condition has changed and once the notification thread leaves the synchronized block, all the threads which are waiting for fight for object lock on which they are waiting and lucky thread returns from wait() method …
How are threads synchronized in Java?
Java Synchronized Method 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.
What are the techniques of synchronizing?
Synchronization methods: Overview
| Method | Complexity | Frequency used |
|---|---|---|
| Moving libraries | Low | Medium to high |
| Moving objects | Medium to high | Medium |
| Applying journaled changes | High | Low |
| Refreshing new system | Low | Low |
Can we start a dead thread in Java?
Once a thread enters dead state it cannot be restarted.
Which is lock release wait () or sleep ()?
Wait() method releases lock during Synchronization. Sleep() method does not release the lock on object during Synchronization.
What is the difference between notify () and notifyAll () in Java?
As in the case of notify() method, the notification is sent to a single thread among the multiple waiting threads, so it is sure that which of those waiting threads is going to receive the lock. On the other hand, notifyAll() sends a notification to all waiting threads.