Implement producer-consumer problem using threads. PPL Practical Question.
// Java program to implement solution of producer
// consumer problem.
import java.util.LinkedList;
public class ProducerConsumer {
public static void main(String[] args)
throws InterruptedException {
// Object of a class that has both produce()
// and consume() methods
final PC pc = new PC();
// Create producer thread
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
try {
pc.produce();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
// Create consumer thread
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
try {
pc.consume();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
// Start both threads
t1.start();
t2.start();
// t1 finishes before t2
t1.join();
t2.join();
}
// This class has a list, producer (adds items to list
// and consumber (removes items).
public static class PC {
// Create a list shared by producer and consumer
// Size of list is 2.
LinkedList<Integer> list = new LinkedList<>();
int capacity = 2;
// Function called by producer thread
public void produce() throws InterruptedException {
int value = 0;
while (true) {
synchronized (this) {
// producer thread waits while list
// is full
while (list.size() == capacity)
wait();
System.out.println("Producer produced-"
+ value);
// to insert the jobs in the list
list.add(value++);
// notifies the consumer thread that
// now it can start consuming
notify();
// makes the working of program easier
// to understand
Thread.sleep(1000);
}
}
}
// Function called by consumer thread
public void consume() throws InterruptedException {
while (true) {
synchronized (this) {
// consumer thread waits while list
// is empty
while (list.size() == 0)
wait();
//to retrive the ifrst job in the list
int val = list.removeFirst();
System.out.println("Consumer consumed-"
+ val);
// Wake up producer thread
notify();
// and sleep
Thread.sleep(1000);
}
}
}
}
}