使用synchronized锁

package com.ysf;public class Tst02AtomicSync {private static int count = 0;public static void increment() {synchronized (Tst02AtomicSync.class) {count++;}try {Thread.sleep(10L);} catch (InterruptedException e) {e.printStackTrace();}}public static void main(String[] args) throws InterruptedException {Thread t1 = new Thread(() -> {for (int i = 0; i < 100; i++) {increment();}}, "plus-1");Thread t2 = new Thread(() -> {for (int i = 0; i < 100; i++) {increment();}}, "plus-2");t1.start();t2.start();t1.join();t2.join();System.out.println(count);}
}

 public static void increment();descriptor: ()Vflags: ACC_PUBLIC, ACC_STATICCode:stack=2, locals=2, args_size=00: ldc 2: dup3: astore_04: monitorenter                      // 进入了锁5: getstatic                         // 从主内存取值8: iconst_19: iadd                              // ++10: putstatic     #3                  // 往主内存放值13: aload_014: monitorexit

• synchronized 破坏了多线程操作临界资源的特性，保证同一时间下，只有一个线程可以获取到临界资源进行操作