多线程 -- 锁 lock condition

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lock锁的等待与唤醒

 

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相关接口

 

public interface Condition {

    void await() throws InterruptedException;  //等待，响应中断

    void awaitUninterruptibly();               //等待，不响应中断

    long awaitNanos(long nanosTimeout) throws InterruptedException;
                                               //限时等待

    boolean await(long time, TimeUnit unit) throws InterruptedException;
                                               //限时等待

    boolean awaitUntil(Date deadline) throws InterruptedException;
                                               //等待到某一时间

    void signal();     //唤醒一个线程

    void signalAll();  //唤醒所有线程

}

 

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使用示例：

 

class Test9{

    private ReentrantLock lock=new ReentrantLock();
    private Condition condition1=lock.newCondition();
    private Condition condition2=lock.newCondition();

    public void test(){
        try{
            lock.lock();
            System.out.println("condition1 获得锁："+System.currentTimeMillis());
            Thread.sleep(1000);
            System.out.println("condition1 即将进入等待"+System.currentTimeMillis());
            System.out.println();
            condition1.await();
            System.out.println("condition1 再次获得锁："+System.currentTimeMillis());
            Thread.sleep(2000);
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            System.out.println("condition1 释放锁："+System.currentTimeMillis());
            System.out.println();
            lock.unlock();
        }
    }

    public void test2(){
        try{
            lock.lock();
            System.out.println("condition2 获得锁："+System.currentTimeMillis());
            Thread.sleep(1000);
            System.out.println("condition2 即将进入等待"+System.currentTimeMillis());
            System.out.println();
            Thread.sleep(2000);
            condition2.await();
            System.out.println("condition2 再次获得锁："+System.currentTimeMillis());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            System.out.println("condition2 释放锁："+System.currentTimeMillis());
            System.out.println();
            lock.unlock();
        }
    }

    public void test3(){
        try{
            lock.lock();
            System.out.println("唤醒condition1获得锁："+System.currentTimeMillis());
            condition1.signal();
            System.out.println("已经唤醒condition1");
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            System.out.println("唤醒condition1 释放锁："+System.currentTimeMillis());
            System.out.println();
            lock.unlock();
        }
    }

    public void test4(){
        try {
            lock.lock();
            System.out.println("唤醒condition2 获得锁："+System.currentTimeMillis());
            condition2.signal();
            System.out.println("已经唤醒condition2");
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            System.out.println("唤醒condition2 释放锁"+System.currentTimeMillis());
            System.out.println();
            lock.unlock();
        }
    }
}

class Thread9 implements Runnable{

    private Test9 test9;
    private int flag;

    Thread9(Test9 test9,int flag){
        this.test9=test9;
        this.flag=flag;
    }

    @Override
    public void run() {
        switch (flag){
            case 1: test9.test(); break;
            case 2: test9.test2(); break;
            case 3: test9.test3(); break;
            case 4: test9.test4(); break;
        }
    }
}

public class ThreadTest9 {

    public static void main(String[] args){
        Test9 t=new Test9();
        Thread9 t1=new Thread9(t,1);
        Thread9 t2=new Thread9(t,2);
        Thread9 t3=new Thread9(t,3);
        Thread9 t4=new Thread9(t,4);

        Thread thread1=new Thread(t1);
        Thread thread2=new Thread(t2);
        Thread thread3=new Thread(t3);
        Thread thread4=new Thread(t4);

        thread1.start();
        thread2.start();

        try{
            Thread.sleep(1000);
        }catch (Exception e){
            e.printStackTrace();
        }

        thread3.start();
        thread4.start();
    }
}

 

 

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控制台输出：

 

 

condition1 获得锁：1568856711825
condition1 即将进入等待1568856712840

condition2 获得锁：1568856712841
condition2 即将进入等待1568856713842

唤醒condition1获得锁：1568856715848
已经唤醒condition1
唤醒condition1 释放锁：1568856715849

唤醒condition2 获得锁：1568856715851
已经唤醒condition2
唤醒condition2 释放锁1568856715853

condition1 再次获得锁：1568856715854
condition1 释放锁：1568856717857

condition2 再次获得锁：1568856717860
condition2 释放锁：1568856717861