<<–2/”>a href=”https://exam.pscnotes.com/5653-2/”>p>In Java, wait() and sleep() are two different methods used for controlling the execution of threads. While both serve the purpose of making threads pause their execution, they are used in distinct contexts and have different behaviors and implications. Understanding the differences, advantages, and disadvantages of these methods is crucial for developers working with multi-threaded applications.
| Feature | wait() |
sleep() |
|---|---|---|
| Defined In | Object class |
Thread class |
| Usage Context | Used for inter-thread Communication | Used for pausing the execution of a thread |
| Synchronization Requirement | Must be called within a synchronized block or method | Does not require synchronization |
| Release of Lock | Releases the lock on the object | Does not release any locks |
| Wake-up Mechanism | Woken up by notify() or notifyAll() |
Wakes up automatically after the specified time or if interrupted |
| Interrupt Handling | Throws InterruptedException |
Throws InterruptedException |
| Duration Control | Waits until notified | Waits for the specified time |
| Purpose | Coordination between threads | Delays the execution of the current thread |
| Object-Level Method | Yes | No |
| Static Method | No | Yes |
A1: No, wait() must be called within a synchronized block or method. Otherwise, an IllegalMonitorStateException is thrown.
A2: No, sleep() does not release any locks held by the thread when it is called.
A3: Yes, sleep() can be interrupted by another thread, causing it to throw InterruptedException.
A4: The thread will remain in the waiting state indefinitely until it is notified.
A5: No, wait() is not a static method; it is called on an instance of an object.
A6: No, sleep() is not intended for inter-thread communication. It only pauses the current thread for a specified duration.
A7: The default time unit for sleep() is milliseconds.
A8: A thread can be woken up from wait() by a call to notify() or notifyAll() on the same object that it is waiting on.
A9: Yes, wait() can be called on any object, but it must be within a synchronized context of that object.
A10: The main purpose of wait() is to facilitate inter-thread communication and synchronization by making the calling thread wait until another thread notifies it.
Understanding the differences, advantages, and disadvantages of wait() and sleep() is essential for effective multi-threaded programming in Java. While both methods pause thread execution, wait() is designed for inter-thread communication and requires synchronization, whereas sleep() is used for simple delays without synchronization. Proper use of these methods can lead to efficient and synchronized thread behavior, avoiding common pitfalls like deadlocks and busy-waiting.