今天写一个测试类，主要是测试wait(long timeout)到底会不会自动notify，到后来发现
一些很诡异的东西。
package com.hp.thread.chapter04;
public class WaitAndNotify {
private Object obj = new Object();
public static void testPureWait(){
new Thread(new Runnable(){
public void run() {
synchronized (this) {
try {
System.out.println("thread 0");
wait();
System.out.println("thread 0 waited...");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
new Thread(new Runnable(){
public void run() {
synchronized (this) {
try {
System.out.println("thread 1");
wait(1000);
System.out.println("thread 1 waited...");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
public void testWait1000(){
new Thread(new Runnable(){
public void run() {
System.out.println("thread 0 " + this);
synchronized (obj) {
while(true){
try {
System.out.println("thread 0 running...");
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}).start();
new Thread(new Runnable(){
public void run() {
System.out.println("thread 1 " + this);
synchronized (obj) {
try {
while(true){
wait(1000);
System.out.println("thread 1 waited...");
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
//通过打印出来的this，发现2个是不同的结果，为什么呢？
//因为this是指向当前对象的引用，不过方法中都是new Thread(new Runnable(){}).start()
//方式来生成，都是通过匿名的方式，所以每次的this都是指向new Thread()的WaitAndNotify对象
public void testWait1000_2(){
new Thread(new Runnable(){
public void run() {
synchronized (this) {
while(true){
try {
System.out.println("thread 0");
System.out.println("thread 0 running...");
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}).start();
new Thread(new Runnable(){
public void run() {
synchronized (this) {
try {
while(true){
System.out.println("thread 1");
wait(1000);
System.out.println("thread 1 waited...");
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
public static void testWait(){
new Thread(new Runnable(){
public void run() {
while(true){
synchronized (this) {
try {
System.out.println("...");
wait();
System.out.println("waited...");
notifyAll();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}).start();
new Thread(new Runnable(){
public void run() {
while(true){
synchronized (this) {
try {
notifyAll();
System.out.println("notify...");
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}).start();
}
/**
* @param args
*/
public static void main(String[] args) {
// testPureWait();
// testWait();
new WaitAndNotify().testWait1000();
}
}
调用testWait1000_2方法得到的结果不是我期望（线程0始终在运行，线程1是不会运行的），但世界的结果恰恰相反，好事2个线程不相干，测试结果如下
thread 0 thread 0 running... thread 1 thread 1 waited... thread 0 thread 0 running... thread 1 thread 0 thread 0 running... thread 1 waited... thread 1
但是运行testWait1000正好是我要的结果，开始百思不得其解，后来打印this发现mystery了
thread 0 com.hp.thread.chapter04.WaitAndNotify$3@525483cd thread 0 running... thread 1 com.hp.thread.chapter04.WaitAndNotify$4@67f1fba0 thread 0 running... thread 0 running... thread 0 running... thread 0 running...
发现2个this的地址完全不一样，细想一下豁然开朗。
