测试代码如下：
package lhever.JVM;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAdder;
public class AtomicTest
{
public static final int MAX_THREAD_COUNT =
10;
private static final int TASK_COUNT =
10;
private static final int TARGET_COUNT =
100000000;
private AtomicLong atomicLongVal =
new AtomicLong(
0);
private LongAdder longAdderVal =
new LongAdder();
private static CountDownLatch latchForAtomicLong =
new CountDownLatch(TASK_COUNT);
private static CountDownLatch latchForLongAdder =
new CountDownLatch(TASK_COUNT);
public class AtomicLongThread implements Runnable {
protected String name;
protected long startTime;
public AtomicLongThread(
long startTime) {
this.startTime = startTime;
}
@Override
public void run()
{
long v = atomicLongVal.get();
while(v < TARGET_COUNT) {
v = atomicLongVal.incrementAndGet();
}
long endTime = System.currentTimeMillis();
System.out.println(
"AtomicLongThread Spend:" + (endTime - startTime) +
"ms, v = " + v);
latchForAtomicLong.countDown();
}
}
public class LongAddderThread implements Runnable {
protected String name;
protected long startTime;
public LongAddderThread(
long startTime) {
this.startTime = startTime;
}
@Override
public void run()
{
long v = longAdderVal.sum();
while(v < TARGET_COUNT) {
longAdderVal.increment();
v = longAdderVal.sum();
}
long endTime = System.currentTimeMillis();
System.out.println(
"LongAddderThread Spend:" + (endTime - startTime) +
"ms, v = " + v);
latchForLongAdder.countDown();
}
}
public void testAtomicLongThread()
throws InterruptedException {
ExecutorService exe = Executors.newFixedThreadPool(MAX_THREAD_COUNT);
long startTime = System.currentTimeMillis();
AtomicLongThread atomicIntegerThread =
new AtomicLongThread(startTime);
for(
int i =
0; i < TASK_COUNT; i++) {
exe.submit(atomicIntegerThread);
}
latchForAtomicLong.await();
exe.shutdown();
}
public void testLongAdderThread()
throws InterruptedException {
ExecutorService exe = Executors.newFixedThreadPool(MAX_THREAD_COUNT);
long startTime = System.currentTimeMillis();
LongAddderThread longAddderThread =
new LongAddderThread(startTime);
for(
int i =
0; i < TASK_COUNT; i++) {
exe.submit(longAddderThread);
}
latchForLongAdder.await();
exe.shutdown();
}
/**
* 下面的测试表明，AtomicLong的并发性能比LongAdder要差，在线程竞争越剧烈的场合，其表现出来的性能会更加优越
* @param args
* @throws InterruptedException
* @author lhever 2017年4月4日 下午11:10:06
* @since v1.0
*/
public static void main(String[] args)
throws InterruptedException {
/**
* MAX_THREAD_COUNT、TASK_COUNT的值都为3时候测试结果如下：
*/
AtomicTest test =
new AtomicTest();
test.testAtomicLongThread();
test.testLongAdderThread();
/**
* MAX_THREAD_COUNT、TASK_COUNT的值都为10时候测试结果如下：
*/
AtomicTest test1 =
new AtomicTest();
test1.testAtomicLongThread();
test1.testLongAdderThread();
}
}
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