Question

Write a program that launches 50 threads. Each thread should add one to a variable named sum that is initialized to zero. Run the program with and without synchronization to see its effect.

IN JAVA PLEASE

ALSO PLEASE SPECIFY HOW TO RUN THIS PROGRAM - WITH AND WITHOUT SYNCHRONIZATION

THANK YOU

Answer 1

Program without Synchronization

class Demo implements Runnable {
   static int sum = 0;// static sum variable

   @Override
   public void run() {
       ++sum;// adding 1 to sum
   }
}

public class Test {

   public static void main(String[] args) {
       Thread[] ar = new Thread[50];// creating an array of 50 threads
       for (int i = 0; i < 50; i++) {
           // initilizing the array
           ar[i] = new Thread(new Demo());
       }
       long start = System.nanoTime();// getting start time
       for (int i = 0; i < 50; i++) {
           ar[i].start();// starting the threads
       }
       long time = System.nanoTime() - start;// calculating time taken in nanoseconds
       System.out.printf("Took %.1f ms to complete the task\n", time / 1e6);// showing time in milliseconds
       System.out.println("Sum: " + Demo.sum);// showing sum value
   }
}

Program with Synchronization

class Demo implements Runnable {
   static int sum = 0;// static sum variable

   @Override
   public synchronized void run() {//synchronized method
       ++sum;// adding 1 to sum
   }
}

public class Test {

   public static void main(String[] args) {
       Thread[] ar = new Thread[50];// creating an array of 50 threads
       for (int i = 0; i < 50; i++) {
           // initilizing the array
           ar[i] = new Thread(new Demo());
       }
       long start = System.nanoTime();// getting start time
       for (int i = 0; i < 50; i++) {
           ar[i].start();// starting the threads
       }
      
       long time = System.nanoTime() - start;// calculating time taken in nanoseconds
       System.out.printf("Took %.1f ms to complete the task\n", time / 1e6);// showing time in milliseconds
       System.out.println("Sum: " + Demo.sum);// showing sum value
   }
}