package br.com.leonardoz.features.synchronizers;
import java.util.Random;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.Executors;
/**
* Barriers are used for blocking a group of threads until they come together at
* a single point in order to proceed. Basically, convergence of threads.
*
* Accepts a runnable in it's constructor to be called when the threads reach the
* barrier, but before its unblocked
*
* Most common implementation is cyclic barrier.
*
*/
public class UsingBarriers {
public static void main(String[] args) {
Runnable barrierAction = () -> System.out.println("Well done, guys!");
var executor = Executors.newCachedThreadPool();
var barrier = new CyclicBarrier(10, barrierAction);
Runnable task = () -> {
try {
// simulating a task that can take at most 1sec to run
System.out.println("Doing task for " + Thread.currentThread().getName());
Thread.sleep(new Random().nextInt(10) * 100);
System.out.println("Done for " + Thread.currentThread().getName());
barrier.await();
} catch (InterruptedException | BrokenBarrierException e) {
e.printStackTrace();
}
};
for (int i = 0; i < 10; i++) {
executor.execute(task);
}
executor.shutdown();
}
}
