java变量读写效率测试

时间 2019-11-12

标签 java 变量读写效率测试栏目 Java 繁體版

原文原文链接

主要测试全局变量、局部变量、volatile变量、原子变量的读写效率，源码以下：oop

public class GloableVarientTest {
private long temp = 0;测试

   public void test() {
       long loop = Integer.MAX_VALUE;
       long start = System.currentTimeMillis();
       for (long i = 0; i < loop; i++) {
           temp += i;
       }
       long end = System.currentTimeMillis();
       System.out.println(end - start);
   }atom

   public void testLocal() {
       long loop = Integer.MAX_VALUE;
       long temp = 0;
       long start = System.currentTimeMillis();
       for (long i = 0; i < loop; i++) {
           temp += i;
       }
       long end = System.currentTimeMillis();
       System.out.println(end - start);
   }源码

private volatile long volatileTemp = 0;class

   public void testVolatile() {
       long loop = Integer.MAX_VALUE;
       long start = System.currentTimeMillis();
       for (long i = 0; i < loop; i++) {
           volatileTemp += i;
       }
       long end = System.currentTimeMillis();
       System.out.println(end - start);
   }test

   public void testAtomic() {
       AtomicLong atomicTemp = new AtomicLong(0);
       long loop = Integer.MAX_VALUE;
       long start = System.currentTimeMillis();
       for (long i = 0; i < loop; i++) {
           atomicTemp.addAndGet(i);
       }
       long end = System.currentTimeMillis();
       System.out.println(end - start);
   }效率

   public static void main(String[] args) {
       GloableVarientTest gv = new GloableVarientTest();
       gv.test();
       gv.testLocal();
       gv.testVolatile();
       gv.testAtomic();
   }
}变量

读写效率测试结果：局部变量 > 全局变量 >>> volatile变量 ≈ 原子变量im