高并发编程自己实现独占锁

下面是自己实现的独占锁

package ch4.aqs;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;


public class SelfLock implements Lock {

    private static class Sync extends AbstractQueuedSynchronizer {
        //  表示获取到锁 state= 1 获取到锁，state=0 ，表示这个当前没有线程拿到
        @Override
        protected boolean isHeldExclusively() {
            return getState() == 1;
        }

        @Override
        protected boolean tryAcquire(int arg) {
            if (compareAndSetState(0, 1)) {
                setExclusiveOwnerThread(Thread.currentThread());//  表示当前线程拿到了这个锁

                return true;
            }
            return false;
        }

        @Override
        protected boolean tryRelease(int arg) {
            if (getState()==0) {
                throw  new UnsupportedOperationException();

            }
            setExclusiveOwnerThread(null);//  当前没有线程独占
            setState(0);//  只有拿到锁的线程才会释放锁，所以没有多个线程同时去释放的
            return true;
        }
        Condition  newCondition(){
            return new ConditionObject();
        }
    }
     private final  Sync sync= new Sync();
    @Override
    public void lock() {
        //  获取锁
        sync.acquire(1);// 因为是个独占锁所以是1
    }
    @Override
    public void lockInterruptibly() throws InterruptedException {
        sync.acquireInterruptibly(1);
    }
    @Override
    public boolean tryLock() {
        return sync.tryAcquire(1);
    }
    @Override
    public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
        return sync.tryAcquireNanos(1,unit.tonanos(time));
    }
    @Override
    public void unlock() {
        sync.release(1);
    }
    @Override
    public Condition newCondition() {
        return sync.newCondition();
    }
}

下面进行测试

package ch4.aqs;

import tools.SleepTools;

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class TestMyLock {
    public void test(){
        final Lock lock= new SelfLock();
        class Worker extends Thread{
            @Override
            public void run() {
                while (true){
                    lock.lock();
                    try {
                        SleepTools.second(1);
                        System.out.println(Thread.currentThread().getName());
                        SleepTools.second(1);
                    } finally {
                        lock.unlock();
                    }
                    SleepTools.second(2);
                }
            }
        }
        //  启动10个线程
        for (int i = 0; i < 10; i++) {
            Worker w = new Worker();
            w.setDaemon(true);
            w.start();
        }
        for (int i = 0; i < 10; i++) {
            SleepTools.second(1);
            System.out.println();
        }

    }

    public static void main(String[] args) {
        TestMyLock testMyLock = new TestMyLock();
        testMyLock.test();
    }

}