private static void lockAndExecute(final Runnable runnable, final Iterator<Guardian> guardians) {
if (guardians.hasNext()) {
final Guardian guardian = guardians.next();
ThreadUtils.log("Acquire lock: %s", guardian);
synchronized (guardian) {
ThreadUtils.log("Lock: %s acquired", guardian);
Guardian.lockAndExecute(runnable, guardians);
}
ThreadUtils.log("Release lock: %s", guardian);
} else {
ThreadUtils.log("All locks are acquired. Execute task");
runnable.run();
}
}
public static void main(final String[] args) throws Exception {
// Create a lock and acquire it
final Lock lock = new ReentrantLock();
lock.lock();
try {
// Create another thread that tries to acquire the same lock
final Thread thread =
new Thread(
new Runnable() {
@Override
public void run() {
try {
// Wait a minute before it gives up
ThreadUtils.log("Acquiring the lock...");
if (lock.tryLock(1, TimeUnit.MINUTES)) {
try {
ThreadUtils.log("Working...");
} finally {
lock.unlock();
}
}
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
ThreadUtils.log("Cancelled");
}
}
},
"Thread-1");
thread.start();
// Wait 2 seconds before interrupting the thread
Thread.sleep(2000);
// Cancel the thread from what it is doing and wait for it to finish
thread.interrupt();
thread.join();
} finally {
lock.unlock();
}
ThreadUtils.log("Done");
}