In continuation to what we've learnt in CyclicBarrier , find below code snippet
explaining real time scenario which is a perfect analogy.
In continuation to what we've learnt in CyclicBarrier , find below code snippet explaining real time scenario which is a perfect analogy.
package com.concurrent.jdk5;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
/* 4 bikers starting
from Manali and reaching to Leh after
* crossing 3
checkpoints */
public class CyclicBarrierDemo {
public static void main(String[] args) {
final CyclicBarrier checkPoint = new CyclicBarrier(4, new BarrierAction());
Thread t1 = new Thread(new Biker(checkPoint), "Biker 1");
Thread t2 = new Thread(new Biker(checkPoint), "Biker 2");
Thread t3 = new Thread(new Biker(checkPoint), "Biker 3");
Thread t4 = new Thread(new Biker(checkPoint), "Biker 4");
t1.start();
t2.start();
t3.start();
t4.start();
}
}
/* Worker thread*/
class Biker implements Runnable {
private CyclicBarrier checkPoint;
public Biker(CyclicBarrier checkPoint) {
this.checkPoint = checkPoint;
}
public void run() {
try {
/* All bikers called await() and waiting to end the barrier.
Once number of threads
*
crossing the barrier is equal to number mentioned in above construtor, then
*
last thread entering will call the barrier action which has seperate
implementation*/
System.out.println(Thread.currentThread().getName()
+
" has left Manali");
checkPoint.await();
System.out.println(Thread.currentThread().getName()
+
" has left the first checkpoint /
barrier");
/* Again, all bikers called await() and waiting to end the
barrier. */
checkPoint.await();
System.out.println(Thread.currentThread().getName()
+
" has left the second checkpoint /
barrier");
checkPoint.await();
System.out.println(Thread.currentThread().getName()
+
" has reached Leh");
} catch (InterruptedException
| BrokenBarrierException e) {
e.printStackTrace();
}
}
}
/* barrierAction-the
action to execute when all threads crossed the barrier number */
class BarrierAction implements Runnable {
public void run() {
System.out.println("Barrier Action run by Thread :"+Thread.currentThread().getName());
System.out.println("\nAll bikers have arrived to checkpoint. Lets refill the
petrol\n");
}
}
Output
Biker 1
has left Manali
Biker 4
has left Manali
Biker 3
has left Manali
Biker 2
has left Manali
Barrier
Action run by Thread :Biker 2
All
bikers have arrived to checkpoint. Lets refill the petrol
Biker 2
has left the first checkpoint / barrier
Biker 3
has left the first checkpoint / barrier
Biker 1
has left the first checkpoint / barrier
Biker 4
has left the first checkpoint / barrier
Barrier
Action run by Thread :Biker 4
All
bikers have arrived to checkpoint. Lets refill the petrol
Biker 4
has left the second checkpoint / barrier
Biker 1
has left the second checkpoint / barrier
Biker 2
has left the second checkpoint / barrier
Biker 3
has left the second checkpoint / barrier
Barrier
Action run by Thread :Biker 3
All
bikers have arrived to checkpoint. Lets refill the petrol
Biker 3
has reached Leh
Biker 1
has reached Leh
Biker 2
has reached Leh
Biker 4
has reached Leh
References : http://codepumpkin.com/cyclicbarrier-java-concurrency-utilities/
