java多线程之间的相互通信

小咪咪 2022-05-28 03:43 297阅读 0赞

利用Condition的await方法和signal方法了指定叫醒一个线程、通过变量signal来实现线程之间的通信

import java.util.concurrent.locks.Condition;
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReentrantLock;
    
    public class Demo {
    
        private int signal;
    
        Lock lock = new ReentrantLock();
        Condition a = lock.newCondition();
        Condition b = lock.newCondition();
        Condition c = lock.newCondition();
    
    
        public void a() {
            lock.lock();
            while(signal != 0 ) {
                try {
                    a.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("a");
            signal ++;
            b.signal();
            lock.unlock();
        }
    
        public  void b() {
            lock.lock();
            while(signal != 1) {
                try {
                    b.await();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            System.out.println("b");
            signal ++;
            c.signal();
            lock.unlock();
        }
    
        public  void c () {
            lock.lock();
            while(signal != 2) {
                try {
                    c.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("c");
            signal = 0;
            a.signal();
            lock.unlock();
        }
    
        public static void main(String[] args) {
    
            Demo d = new Demo();
            A a = new A(d);
            B b = new B(d);
            C c = new C(d);
    
            new Thread(a).start();
            new Thread(b).start();
            new Thread(c).start();
    
        }
    }
    
    class A implements Runnable {
    
        private Demo demo;
    
        public A(Demo demo) {
            this.demo = demo;
        }
    
        @Override
        public void run() {
            while(true) {
                demo.a();
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    
    }
    class B implements Runnable {
    
        private Demo demo;
    
        public B(Demo demo) {
            this.demo = demo;
        }
    
        @Override
        public void run() {
            while(true) {
                demo.b();
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    
    }
    class C implements Runnable {
    
        private Demo demo;
    
        public C(Demo demo) {
            this.demo = demo;
        }
    
        @Override
        public void run() {
            while(true) {
                demo.c();
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    
    }