模拟 CAS 算法

package com.atguigu.juc;

/*

• 模拟 CAS 算法
  */
  public class TestCompareAndSwap {

  public static void main(String[] args) {
  final CompareAndSwap cas = new CompareAndSwap();

   for (int i = 0; i < 10; i++) {
   	new Thread(new Runnable() {
   		
   		@Override
   		public void run() {
   			int expectedValue = cas.get();
   			boolean b = cas.compareAndSet(expectedValue, (int)(Math.random() * 101));
   			System.out.println(b);
   		}
   	}).start();
   }
  

  }

}

class CompareAndSwap{

private int value;

//获取内存值
public synchronized int get(){
	return value;
}

//比较
public synchronized int compareAndSwap(int expectedValue, int newValue){
	int oldValue = value;
	
	if(oldValue == expectedValue){
		this.value = newValue;
	}
	
	return oldValue;
}

//判断
public synchronized boolean compareAndSet(int expectedValue, int newValue){
	return expectedValue == compareAndSwap(expectedValue, newValue);
}

}