5 threads each increment a shared int counter 1000 times

描述

5 threads each increment a shared int counter 1000 times.

例子

public class Main {
    private int counter = 0;

    public static void main(String[] args) throws InterruptedException {
    long startTime = System.currentTimeMillis();
    Main sharedCounter1 = new Main();

    Thread thread1 = new Thread(() -> sharedCounter1.increment());
    thread1.start();//from w ww .2 1 doc. ne t
    Thread thread2 = new Thread(() -> sharedCounter1.increment());
    thread2.start();
    Thread thread3 = new Thread(() -> sharedCounter1.increment());
    thread3.start();
    Thread thread4 = new Thread(() -> sharedCounter1.increment());
    thread4.start();
    Thread thread5 = new Thread(() -> sharedCounter1.increment());
    thread5.start();

    thread1.join();
    thread2.join();
    thread3.join();
    thread4.join();
    thread5.join();

    long endTime = System.currentTimeMillis();
    System.out.println("Counter: " + sharedCounter1.counter);
    System.out.println("Total time taken(in millis): " + (endTime - startTime));
}

    public void increment() {
        for (int i = 0; i < 1000; i++) {
            synchronized (Main.class) {
                //                System.out.println(Thread.currentThread().getName());
                counter++;
            }
        }
    }
}