What is a Java ReentrantLock and how do I use it?

What is a Java ReentrantLock and how do I use it?

A ReentrantLock is a synchronization aid that allows threads to lock and unlock resources in Java. It provides more flexibility than synchronized blocks.

Can you give me an example of how to implement a ReentrantLock?

Sure! Here's a simple example:

import java.util.concurrent.locks.ReentrantLock;

public class Counter {
    private int count = 0;
    private final ReentrantLock lock = new ReentrantLock();

    public void increment() {
        lock.lock();
        try {
            count++;
        } finally {
            lock.unlock();
        }
    }

    public int getCount() {
        return count;
    }
}

What are the advantages of using ReentrantLock over synchronized?

ReentrantLock offers more features like tryLock, timed lock waits, and the ability to interrupt threads waiting for a lock, which synchronized does not.

Are there any downsides to using ReentrantLock?

Yes, the main downside is that it requires manual unlocking, which can lead to deadlocks if not handled properly.