Producer Consumer Problem

Author: Tamoziit

java/threads/ProducerConsumer.java

@@ -0,0 +1,77 @@
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class ProducerConsumer {
+ static private Queue<Integer> queue; // object of Queue class
+ private int capacity;
+
+ public ProducerConsumer(int cap) {
+ queue = new LinkedList<>();
+ capacity = cap;
+ }
+
+ public boolean add(int item) { // for producer thread
+ synchronized (queue) { // Queue queue() object used as MUTEX
+ while (queue.size() == capacity) {
+ try {
+ queue.wait(); // wait till queue is not full
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ }
+
+ System.out.print(Thread.currentThread().getName() + " Producing: ");
+ queue.add(item);
+ queue.notifyAll(); // notify all threads that queue is not empty
+ return true;
+ }
+ }
+
+ public int remove() { // for consumer thread
+ synchronized (queue) {
+ while (queue.size() == 0) {
+ try {
+ queue.wait(); // wait till queue is not empty
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ }
+
+ System.out.print(Thread.currentThread().getName() + " Consuming: ");
+ int dequeued = queue.poll(); // dequeueing
+ queue.notifyAll(); // notify all threads that queue is not full
+ return dequeued;
+ }
+ }
+
+ public static void main(String[] args) {
+ System.out.println("Main Thread Starting");
+ ProducerConsumer ob = new ProducerConsumer(10);
+
+ // Producer Threads
+ new Thread(() -> {
+ while (true) {
+ System.out.println(ob.add(100) + "(size = " + queue.size() + ")");
+ }
+ }, "Producer 1").start();
+ new Thread(() -> {
+ while (true) {
+ System.out.println(ob.add(100) + "(size = " + queue.size() + ")");
+ }
+ }, "Producer 2").start();
+
+ // Consumer Threads
+ new Thread(() -> {
+ while (true) {
+ System.out.println(ob.remove() + "(size = " + queue.size() + ")");
+ }
+ }, "Consumer 1").start();
+ new Thread(() -> {
+ while (true) {
+ System.out.println(ob.remove() + "(size = " + queue.size() + ")");
+ }
+ }, "Consumer 2").start();
+
+ System.out.println("Main Thread Exiting");
+ }
+}