JAVA并发，同步锁性能测试

测试主要从运行时间差来体现，数据量越大，时间差越明显，例子如下：

package com.xt.thinks21_2;

/**
 * 同步锁性能测试
 * 
 * @author Administrator
 *
 */
public class SynchronizedTimeTest {
    public volatile int inc = 0;

    public void increase() {
        inc++;
    }

    public static void main(String[] args) {
        final SynchronizedTimeTest test = new SynchronizedTimeTest();
        for (int i = 0; i < 10; i++) {
            new Thread() {
                public void run() {
                    for (int j = 0; j < 10000; j++)
                        test.increase();
                };
            }.start();
        }
        Long time1 = System.currentTimeMillis();
        while (Thread.activeCount() > 1) {
            // 保证前面的线程都执行完
            Thread.yield();
        }
        Long time2 = System.currentTimeMillis();
        System.out.println("time1:" + time1 + " time2:" + time2);
        Long timeDiff = time2 - time1;
        System.out.println("time:" + timeDiff + "-->" + test.inc);
    }
}

上面是方法未加synchronized运行结果：

time1:1429805281187 time2:1429805281187
time:0-->75809

方法添加synchronized运行结果：

time1:1429805416628 time2:1429805416645
time:17-->100000