实践【Java多线程编程核心技术】系列：同步方法造成的无限等待

本文实践来自于【Java多线程编程核心技术】一书！

同步方法容易造成死循环，如——
类Service.java：

package service;
public class Service {

synchronized public void methodA(){
    System.out.println("methodA begin");
    boolean isContinueRun = true;
    while(isContinueRun){       
    }
    System.out.println("methodA end");
}
synchronized public void methodB() {
    System.out.println("methodB begin");
    System.out.println("methodB end");
  }

}

线程类代码如：

package extthread;

import service.Service;

public class ThreadA extends Thread {

private Service service;

public ThreadA(Service service) {
    super();
    this.service = service;
}

@Override
public void run() {
    // TODO Auto-generated method stub
    service.methodA();
}

}

package extthread;
import service.Service;
public class ThreadB extends Thread{

private Service service;

public ThreadB(Service service) {
    super();
    this.service = service;
}

/* (non-Javadoc)
 * @see java.lang.Thread#run()
 */
@Override
public void run() {
    // TODO Auto-generated method stub
    service.methodB();
}

}

运行类：

package test.run;
import service.Service;
import extthread.ThreadA;
import extthread.ThreadB;

public class Run {

public static void main(String[] args) {
    Service service = new Service();
    ThreadA athread = new ThreadA(service);
    athread.start();
    ThreadB bthread = new ThreadB(service);
    bthread.start();
}

}

相关死循环分析——
线程B永远得不到执行机会，被锁死了！

screenshot_20160525155141.png