What is the difference between CountDownLatch and CyclicBarrier in Java concurrency?

CountDownLatch and CyclicBarrier are both used in and are part of a multi-threaded environment.

According to Java Doc -

CountDownLatch - A synchronization aid that allows one or more threads to wait until a set of operations performed in other threads is completed.

CyclicBarrier - A synchronization aid that allows a group of threads to wait for each other to reach a common barrier point.

##2RunningIt has a constructor that can provide Runnable. It has no such constructor3Thread /taskIt maintains thread countIt maintains task count tr>4.5CyclicBarrier Example

gentlemen. No.	Key	CyclicBarrier	CountDownLatch
1	Basic	Allows synchronization of a group of threads all waiting for each other to reach a common obstacle point.	A synchronization aid that allows one or more threads to wait for a set of operations performed in other threads to complete.
##Can be advanced	It is not recommended to use	It is recommended to use.
Exception	If a thread is blocked while waiting If interrupted, all other waiting threads will throw BrokenBarrierException	Only the current thread will throw	InterruptedException and will not affect other threads

public class Main {
   public static void main(String args[]) throws InterruptedException {
      ExecutorService executors = Executors.newFixedThreadPool(4);
      CyclicBarrier cyclicBarrier = new CyclicBarrier(5);
      executors.submit(new Service1(cyclicBarrier));
      executors.submit(new Service1(cyclicBarrier));
      executors.submit(new Service2(cyclicBarrier));
      executors.submit(new Service2(cyclicBarrier));
      executors.submit(new Service2(cyclicBarrier));
      Thread.sleep(3000);
      System.out.println("Done");
   }
}
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
public class Service1 implements Runnable {
   CyclicBarrier cyclicBarrier;
   public Service1(CyclicBarrier cyclicBarrier) {
      super();
      this.cyclicBarrier = cyclicBarrier;
   }
   @Override
   public void run() {
      System.out.println("Services1" + cyclicBarrier.getNumberWaiting());
      while (true) {
         try {
            cyclicBarrier.await();
         } catch (InterruptedException | BrokenBarrierException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }
      }
   }
}
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
public class Service2 implements Runnable {
   CyclicBarrier cyclicBarrier;
   public Service2(CyclicBarrier cyclicBarrier) {
      super();
      this.cyclicBarrier = cyclicBarrier;
   }
   @Override
   public void run() {
      System.out.println("Services2" + cyclicBarrier.getNumberWaiting());
      while (true) {
         try {
            cyclicBarrier.await();
         } catch (InterruptedException | BrokenBarrierException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }
      }
   }
}

CountDownLatch Example

public class Main {
   public static void main(String args[]) throws InterruptedException {
      ExecutorService executors = Executors.newFixedThreadPool(4);
      CountDownLatch latch= new CountDownLatch(2);
      executors.submit(new Service1(latch));
      executors.submit(new Service2(latch));
      latch.await();
      System.out.println("Done");
   }
}
import java.util.concurrent.CountDownLatch;

public class Service1 implements Runnable {

   CountDownLatch latch;
   public Service1(CountDownLatch latch) {
      super();
      this.latch = latch;
   }

   @Override
   public void run() {
      try {
         Thread.sleep(20000);
      } catch (InterruptedException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
      latch.countDown();
      System.out.println("Services2"+latch.getCount());
   }
}
import java.util.concurrent.CountDownLatch;
public class Service2 implements Runnable {
   CountDownLatch latch;
   public Service2(CountDownLatch latch) {
      super();
      this.latch = latch;
   }
   @Override
   public void run() {
      try {
         Thread.sleep(20000);
      } catch (InterruptedException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
      latch.countDown();
      System.out.println("Services2"+latch.getCount());
   }
}

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