public class MyThreadPrinter2 implements Runnable {
private String name;
private Object prev;
private Object self;
private MyThreadPrinter2(String name, Object prev, Object self) {
this.name = name;
this.prev = prev;
this.self = self;
}
@Override
public void run() {
int count = 10;
while (count > 0) {
synchronized (prev) {
synchronized (self) {
System.out.print(name);
count--;
try{
Thread.sleep(1);
}
catch (InterruptedException e){
e.printStackTrace();
}
self.notify();
}
try {
prev.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) throws Exception {
Object a = new Object();
Object b = new Object();
Object c = new Object();
MyThreadPrinter2 pa = new MyThreadPrinter2("A", c, a);
MyThreadPrinter2 pb = new MyThreadPrinter2("B", a, b);
MyThreadPrinter2 pc = new MyThreadPrinter2("C", b, c);
new Thread(pa).start();
Thread.sleep(10);
new Thread(pb).start();
Thread.sleep(10);
new Thread(pc).start();
Thread.sleep(10);
}
}
我对这里的notify和wait ,a,b,c谁先拿到锁不太理解??
还有就是两层synchronized 也是理解不了。求详细解答啊!!
求高手解释一下,谢谢了!!
private String name;
private Object prev;
private Object self;
private MyThreadPrinter2(String name, Object prev, Object self) {
this.name = name;
this.prev = prev;
this.self = self;
}
@Override
public void run() {
int count = 10;
while (count > 0) {
synchronized (prev) {
synchronized (self) {
System.out.print(name);
count--;
try{
Thread.sleep(1);
}
catch (InterruptedException e){
e.printStackTrace();
}
self.notify();
}
try {
prev.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) throws Exception {
Object a = new Object();
Object b = new Object();
Object c = new Object();
MyThreadPrinter2 pa = new MyThreadPrinter2("A", c, a);
MyThreadPrinter2 pb = new MyThreadPrinter2("B", a, b);
MyThreadPrinter2 pc = new MyThreadPrinter2("C", b, c);
new Thread(pa).start();
Thread.sleep(10);
new Thread(pb).start();
Thread.sleep(10);
new Thread(pc).start();
Thread.sleep(10);
}
}
我对这里的notify和wait ,a,b,c谁先拿到锁不太理解??
还有就是两层synchronized 也是理解不了。求详细解答啊!!
求高手解释一下,谢谢了!!
wait/notify方法,都是成对出现的,楼主展现的代码里面,都是单个出现的,很让人诧异。
其次,
wait/notify方法的使用中,wait方法必须让现场持有该对象的监听器,所以,必须添加synchronized块。
当线程调用wait方法时,释放该对象的锁,
而notify则不存在这个事情,所以,notify方法可以不用被synchronized块包围。
这是多线程里面比较经典的一个例子,三个线程循环打印10次ABC
notify一样要持有对象的锁jdk的说明
此方法只应由作为此对象监视器的所有者的线程来调用
IllegalMonitorStateException - 如果当前线程不是此对象监视器的所有者。
然后这样依次执行,打印10次ABC。