Producer Consumer Problem in Java
Producer — Consumer problem
Producer produce the jobs(add element into Queue) and Consumer consume the jobs(remove element from Queue) .
Both are shared a fixed size buffered memory as Queue.
We can solve Producer-Consumer problem
1- by using wait , notify() & notifyAll()
2- Semaphore
1- How to use wait, notify and notifyAll in Java — Producer Consumer Example
package com.application.producer;
import java.util.Queue;
import java.util.Random;
public class Producer extends Thread {
private final Queue<Integer> queue;
private final int maxSize;
public Producer(Queue<Integer> queue, int maxSize, String name) {
super(name);
this.queue = queue;
this.maxSize = maxSize;
}
@Override
public void run() {
while (true) {
synchronized (queue) {
while (queue.size() == maxSize) {
try {
System.out.println(“Buffred size is full”);
queue.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Random random = new Random();
int i = random.nextInt();
System.out.println(“Producing value : “ + i);
queue.add(i);
queue.notifyAll();
}
}
}
}
===========================
package com.application.producer;
import java.util.Queue;
public class Consumer extends Thread {
private final Queue<Integer> queue;
private final int maxSize;
public Consumer(Queue<Integer> queue, int maxSize, String name) {
super(name);
this.queue = queue;
this.maxSize = maxSize;
}
@Override
public void run() {
while (true) {
synchronized (queue) {
while (queue.isEmpty()) {
try {
queue.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
queue.remove();
System.out.println(“Consuming the job”);
queue.notifyAll();
}
}
}
}
================
package com.application.producer;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Random;
public class ProducerConsumerExample {
public static void main(String[] args) {
final Queue<Integer> buffer = new LinkedList<>();
int maxsize = 10;
Producer producer = new Producer(buffer, maxsize, “Producer”);
Consumer consumer = new Consumer(buffer, maxsize, “Consumer”);
Random random = new Random();
int i = random.nextInt();
System.out.println(“produce same” + i);
producer.start();
consumer.start();
}
}
========================================
Output
Producing value : 250629585
Producing value : -316327511
Producing value : -864679355
Producing value : 38374974
Producing value : 1229081603
Producing value : -775385974
Producing value : -822954575
Producing value : -78390043
Producing value : 44810827
Producing value : -1987790057
Buffred size is full
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
Consuming the job
