1. 程式人生 > >實現執行緒間的通訊(二)

實現執行緒間的通訊(二)

非靜態的同步方法的鎖物件:this

靜態的同步方法的鎖物件是:該類的位元組碼物件

this.notify():喚醒單個等待的執行緒

this.notifyAll():喚醒所有等待的執行緒

/*
 *      1.在同步程式碼塊中,用哪個物件鎖,就用那個物件呼叫wait方法
 *      2.為什麼wait方法和notify方法可以定義在Object這類中
 *          因為鎖物件是任意物件,Object類是所有類的基類
 *      3.sleep方法和wait方法的區別:
 *          wait方法可以傳入引數(就是在引數的時間結束後等待),也可以不傳入引數(直接等待),
 *          sleep方法在同步函式或者同步程式碼塊中,不釋放鎖
 *          wait方法在同步函式或者同步程式碼塊中,釋放鎖
 */

JDK1.5:(三個執行緒輪流執行)

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

public class DenoNotify2 {

    public static void main(String[] args) {
        final Print2 p=new Print2();
        new Thread(){
            public void run(){
                while (true){
                    try {
                        p.print1();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        new Thread(){
            public void run(){
                while (true){
                    try {
                        p.print2();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        new Thread(){
            public void run(){
                while (true){
                    try {
                        p.print3();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
    }
}

class Print2{
    private ReentrantLock r=new ReentrantLock();
    private Condition c1=r.newCondition();
    private Condition c2=r.newCondition();
    private Condition c3=r.newCondition();

    private int flag=1;
    public void print1() throws Exception{
        r.lock();
            if (flag!=1){
                c1.await();
            }
            System.out.print("1");
            System.out.print("2");
            System.out.print("3");
            System.out.print("4");
            System.out.println("5");
            flag=2;
            c2.signal();
        r.unlock();
    }
    public void print2() throws Exception{
        r.lock();
            if (flag!=2){
                c2.await();
            }
            System.out.print("上");
            System.out.print("山");
            System.out.print("打");
            System.out.print("老");
            System.out.println("虎");
            flag=3;
           c3.signal();
        r.unlock();
    }
    public void print3() throws Exception{
        r.lock();
            if (flag!=3){
                c3.await();
            }
            System.out.print("a");
            System.out.print("b");
            System.out.print("c");
            System.out.print("d");
            System.out.println("e");
            flag=1;
            c1.signal();
        r.unlock();
    }
}