Wait and notify

Wait ()

Causes the current thread to wait before another thread calls the Notify () method or the Notifyall () method of this object.

Notify ()
Wakes up a single thread waiting on this object monitor.

Package com.icss.biz.ppt;


/**
* Thinking in Java p627
* @author XIAOHP
*
*/
public class Waittest {
public static void Main (string[] args) {

Restaurant restaurant = new Restaurant ();
Waiter waiter = new Waiter (restaurant);
Waiter.start ();
Chef Chef = new Chef (restaurant,waiter);
Chef.start ();
}
}


Class Restaurant {
Public order;
}


Class order{
private static int i=0;
private int m_count;
Public order () {
M_count = i++;
if (m_count==10) {
SYSTEM.OUT.PRINTLN ("No food, end!");
System.exit (0);
}
}
}


Class Waiter extends Thread
{
Private restaurant M_restaurant;

Public Waiter (restaurant R) {
M_restaurant = R;
}

public void Run () {
while (M_restaurant.order = = null) {
Synchronized (this) {
try {
System.out.println ("Waiter thread id=" + thread.currentthread (). GetId () + "Waiting");
Wait (); Wait for the notification to be notified before running down
M_restaurant.order = null;
System.out.println ("Waiter thread id=" + thread.currentthread (). GetId () + "receive notification, take order \ n");
catch (Exception e) {
}
}
}
}
}


Class Chef extends thread{
Private restaurant M_restaurant;
Private Waiter M_waiter;
Public Chef (Restaurant Restaurant,waiter waiter) {
M_restaurant = restaurant;
M_waiter = Waiter;
}
public void Run () {
while (true) {
if (M_restaurant.order = = null) {
M_restaurant.order = New Order ();
System.out.println ("Chef thread id=" + thread.currentthread (). GetId () + "received New Order");

Synchronized (m_waiter) {
System.out.println ("Chef thread id=" + thread.currentthread (). GetId () + "----Notice waiter fetch food");
M_waiter.notify (); Inform waiter to fetch food
}

The following code moves to the sychronized and a deadlock occurs.
try {
Thread.Sleep (1000);
catch (Exception e) {
}
}

}
}
}