ReentrantLock和Synchronized简单比较

//**************synchronized的实现方式******************
// 1、用于代码块
synchronized(this){}
// 2、用于实例对象
synchronized(object){}
// 3、用于方法
public synchronized void test(){}
// 4、可重入
for(int i=0;i<10;i++){
   synchronized(this){}   
}
// *********************ReentrantLock使用方式***********************
public void test() throws Exception{
    //1、初始化选择公平锁，非公平锁
    ReentrantLock lock = new ReentrantLock(true);    
    //2、用于代码块
    lock.lock();
    try{
        try{
            //3、支持多种加锁方式，比较灵活，具有可重入特性
            if(lock.tryLock(10,TimeUtil.MILLISECONDS)){}
         }finally{
           //4、手动释放锁 
           lock.unlock();
        }
    } finally{
       lock.unlock();
    }       
}

package com.kit.mok;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
/**
 * @author 七彩星星
 * @version 1.0
 * @date 2021/7/26 16:59
 */
public class Aqslock {
    public static class Sync extends AbstractQueuedSynchronizer {
        @Override
        protected boolean tryAcquire(int args) {
            return compareAndSetState(0, 1);
        }
        @Override
        protected boolean tryRelease(int args) {
            setState(0);
            return true;
        }
        @Override
        protected boolean isHeldExclusively() {
            return getState() == 1;
        }
    }
    private Sync sync = new Sync();
    public void lock() {
        sync.acquire(1);
    }
    public void unlock() {
        sync.release(1);
    }
}

package com.kit.mok;
/**
 * @author 七彩星星
 * @version 1.0
 * @date 2021/7/26 17:05
 */
public class AqsMain {
    static int count = 0;
    static Aqslock reentrantLock = new Aqslock();
    // static ReentrantLock reentrantLock = new ReentrantLock(false);
    public static void main(String[] args) throws InterruptedException {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                try {
                    aqslock.lock();
                    for (int i = 0; i < 10000; i++) {
                        count ++;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    aqslock.unlock();
                }
            }
        };
        Thread thread1=new Thread(runnable);
        Thread thread2=new Thread(runnable);
        thread1.start();
        thread2.start();
        thread1.join();
        thread2.join();
        System.out.println(count);
    }
}