Java并发编程中的join()与interrupt()函数

     刚刚写了下Java的并发程序，在此做个笔记。对于线程a和b，在线程b中调用a.join()，那么此时线程b将会被挂起，直至线程a执行完才会有线程b执行的机会，若想打破这种机制，可以调用a.interrupt()，这时，线程b可以不必受刚才的约束。

 

import java.util.concurrent.*;

class Sleeper extends Thread {
//private String name;
private int duration;

public Sleeper(String name, int duration){
super(name);
this.duration = duration;
start();
}
public void run(){
try{
System.out.println(getName() + " before sleep.");
TimeUnit.MILLISECONDS.sleep(duration);
System.out.println(getName() + " is asleep.");
}catch(InterruptedException e){
System.out.println(getName() + " was interrupted. " + " isInterrupted(): " + isInterrupted());
return;
}
System.out.println(getName() + " has awakened.");
}
}

class Joiner extends Thread{
private Sleeper sleeper;
public Joiner(String name, Sleeper sleeper){
super(name);
this.sleeper = sleeper;
start();
}

public void run(){
try{
System.out.println(getName() + " before join.");
sleeper.join();
System.out.println(getName() + " after join.");
}catch (InterruptedException e) {
System.out.println(getName() + " was interrupted.");
}
System.out.println(getName() + " join completed.");
}
}
public class ConcurrentBasic {
public static void main(String args[]){
Sleeper sleepy = new Sleeper("Sleepy", 3000);
Sleeper grumpy = new Sleeper("Grumpy", 3000);
Joiner dopey = new Joiner("Dopey", sleepy);
Joiner doc = new Joiner("Doc", grumpy);

grumpy.interrupt();

}
}

      grumpy在这被打断了，那么和它join的doc将会被唤醒，从而导致doc线程的执行，这里可以把grumpy.interrupt()改为doc.interrupt()，运行情况与预想差不多。