package concurrency;

import java.util.concurrent.*;

import java.util.concurrent.locks.*;

/**

* RUN:

* javac concurrency/AttemptLocking.java && java concurrency.AttemptLocking

*

* OUTPUT:

*

*/

public class AttemptLocking {

private ReentrantLock lock = new ReentrantLock();

public void untimed() {

boolean captured = lock.tryLock();

try {

System.out.println("trylock(): " + captured);

}

finally {

if (captured) {

lock.unlock();

}

}

}

public void timed() {

boolean captured = false;

try {

captured = lock.tryLock(2, TimeUnit.SECONDS);

}

catch (InterruptedException e) {

throw new RuntimeException(e);

}

try {

System.out.println("tryLock(2, TimeUnit.SECONDS): " + captured);

}

finally {

if (captured) {

lock.unlock();

}

}

}

public static void main(String[] args) throws InterruptedException {

final AttemptLocking al = new AttemptLocking();

al.untimed();

al.timed();

new Thread() {

{

setDaemon(true);

}

public void run() {

al.lock.lock();

System.out.println("acquired");

}

}.start();

// Thread.yield();

TimeUnit.MILLISECONDS.sleep(50);

al.untimed();

al.timed();

}

}