notify 和wait 2

1. 在這個例子中，休眠（Thread.sleep()）被放在同步語句之外，因而程式有較高的執行效率。

在前一個例子中，sleep()放在同步語句之內，使得只有一個線程的synchnoize塊執行完，才能執行其他的線程同步塊，因而效率非常低

 

2. 單個線程的異常不會影響其他的線程

 

類Product.java

import java.util.List;<br />/**<br /> * @author Administrator<br /> *<br /> * TODO To change the template for this generated type comment go to<br /> * Window - Preferences - Java - Code Style - Code Templates<br /> */<br />public class Product implements Runnable {<br />private List container = null;<br />private int count;<br />public Product(List lst) {<br />this.container = lst;<br />}<br />public void run() {<br />while (true) {<br />System.out.println("container.size()=" + container.size() + "," + Thread.currentThread().getThreadGroup().activeCount() +<br />"," + Thread.activeCount());</p><p>//Thread[] threads = new Thread[Thread.activeCount()];<br />//Thread.enumerate(threads);<br />//<br />//for (int j = 0; j < threads.length; j++) {<br />//StackTraceElement[] ste = threads[j].getStackTrace();<br />//for (int i = 0; i < ste.length; i++) {<br />//System.out.println(threads[j].getName() + ste[i]);<br />//}<br />//}</p><p>synchronized (container) {<br />if (container.size() > MultiThread.MAX) {<br />try {<br />System.out.println("Exceed the MAX limit.");<br />container.wait();<br />} catch (InterruptedException e) {<br />e.printStackTrace();<br />}<br />}else{<br />container.add(new Object());<br />container.notify(); //自動通知，快速生產<br />System.out.println("我生產了" + (++count) + "個");<br />}<br />//container.add(new Object());<br />//container.notify();<br />//System.out.println("我生產了" + (++count) + "個");<br />}</p><p>//try {<br />//Thread.sleep(10);<br />//} catch (InterruptedException e) {<br />//e.printStackTrace();<br />//}<br />}<br />}<br />}

 

 

 

 

 

類Consume.java

 

import java.util.List;<br />/**<br /> * @author Administrator<br /> *<br /> * TODO To change the template for this generated type comment go to<br /> * Window - Preferences - Java - Code Style - Code Templates<br /> */<br />public class Consume implements Runnable {<br /> private List container = null;<br /> private int count;</p><p> private String flag = "test is ok";<br /> public Consume(List lst) {<br /> this.container = lst;<br /> }<br /> public void run() {<br /> while (true) {<br /> synchronized (container)<br /> {<br />// if (container.size() == 0) {<br />// try {<br />// System.out.println("container.size=0");<br />// container.wait();//放棄鎖<br />// } catch (InterruptedException e) {<br />// e.printStackTrace();<br />// }<br />// }else{<br />// container.remove(0);<br />// //container.notify();<br />// System.out.println("我吃了" + (++count) + "個");<br />// }<br /> if(container.size() > 0){<br /> container.remove(0);<br />// //container.notify();<br /> System.out.println(Thread.currentThread().getId() + "我吃了" + (++count) + "個,還剩" + container.size());<br /> }else{<br /> container.notify();<br /> }<br /> //container.remove(0);<br /> //container.notify();<br /> //System.out.println("我吃了" + (++count) + "個");<br /> }</p><p> try {<br /> Thread.sleep(1000);<br /> } catch (InterruptedException e) {<br /> e.printStackTrace();<br /> }<br /> }<br /> }<br />}<br />

 

類MultiThread.java

 

import java.util.ArrayList;<br />import java.util.List;<br />public class MultiThread {<br /> private List container = new ArrayList();<br /> public final static int MAX = 5;<br /> public static void main(String args[]) {<br /> MultiThread m = new MultiThread();<br /> new Thread(new Consume(m.getContainer())).start();<br /> new Thread(new Product(m.getContainer())).start();<br /> new Thread(new Consume(m.getContainer())).start();<br /> //new Thread(new Product(m.getContainer())).start();<br /> }<br /> public List getContainer() {<br /> return container;<br /> }<br /> public void setContainer(List container) {<br /> this.container = container;<br /> }<br />}