ReentrantLock和synchronized性能比较

最新推荐文章于 2025-07-17 00:10:02 发布

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最新推荐文章于 2025-07-17 00:10:02 发布 · 2.6k 阅读

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#锁

本文探讨了在低并发与高并发场景中，ReentrantLock与synchronized的性能表现。在高并发测试中，计算100000000次，ReentrantLock耗时5789ms，而synchronized耗时8850ms。ReentrantLock借助CAS自旋操作，减少了线程切换带来的资源消耗，因此在高并发环境下性能更优。

ReentrantLock和synchronized在低并发的时候性能差距不大，本次主要测试高并发时的性能。

使用ReentrantLock

public class SysDemoTest implements Runnable{
	
	private HashMap<String,Integer> x;
	
	private CountDownLatch latch;
	
	private CountDownLatch end;
	
	private ReentrantLock lock;
	
	SysDemoTest(HashMap<String,Integer> x,CountDownLatch latch,ReentrantLock lock,CountDownLatch end){
		this.x = x;
		this.latch = latch;
		this.lock = lock;
		this.end = end;
	}
	
	public static void main(String[] args) {
		ReentrantLock lock = new ReentrantLock();
		CountDownLatch latch = new CountDownLatch(1000);
		CountDownLatch end = new CountDownLatch(1000);
		HashMap<String,Integer> x = new HashMap<String,Integer>();
		x.put("1", 0);
		long start = System.currentTimeMillis();
		SysDemoTest test = new SysDemoTest(x,latch,lock,end);
		for(int i = 0 ;i <1000;i++) {
			Thread t = new Thread(test);
			t.start();
			latch.countDown();
		}
		try {
			end