Mega Code Archive
The producer-consumer approach to thread cooperation
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// : c13:Restaurant.java
// The producer-consumer approach to thread cooperation.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
class Order {
private static int i = 0;
private int count = i++;
public Order() {
if (count == 10) {
System.out.println("Out of food, closing");
System.exit(0);
}
}
public String toString() {
return "Order " + count;
}
}
class WaitPerson extends Thread {
private Restaurant restaurant;
public WaitPerson(Restaurant r) {
restaurant = r;
start();
}
public void run() {
while (true) {
while (restaurant.order == null)
synchronized (this) {
try {
wait();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
System.out.println("Waitperson got " + restaurant.order);
restaurant.order = null;
}
}
}
class Chef extends Thread {
private Restaurant restaurant;
private WaitPerson waitPerson;
public Chef(Restaurant r, WaitPerson w) {
restaurant = r;
waitPerson = w;
start();
}
public void run() {
while (true) {
if (restaurant.order == null) {
restaurant.order = new Order();
System.out.print("Order up! ");
synchronized (waitPerson) {
waitPerson.notify();
}
}
try {
sleep(100);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
}
}
public class Restaurant {
Order order; // Package access
public static void main(String[] args) {
Restaurant restaurant = new Restaurant();
WaitPerson waitPerson = new WaitPerson(restaurant);
Chef chef = new Chef(restaurant, waitPerson);
}
} ///:~
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