Buffer.java

/**
 * The `Buffer` class represents a bounded buffer with a fixed capacity.
 * It provides methods for producers to add items to the buffer and
 * consumers to remove items from the buffer. The buffer uses a blocking
 * queue to ensure thread safety. Producers can produce items and add
 * them to the buffer, while consumers can consume items from the buffer.
 * The class also keeps track of the number of producers finished and items
 * produced to determine when all items have been produced and consumed.
 **/



import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;


public class Buffer {
    private BlockingQueue<Integer> buffer;
    private int producersFinished;
    private int itemsProduced;

    public Buffer(int capacity) {
        this.buffer = new ArrayBlockingQueue<>(capacity);
        this.producersFinished = 0;
        this.itemsProduced = 0;
    }
 
    // The produce method is used by producers to add items to the buffer.
    public void produce(long producerID, int itemCount) throws InterruptedException {
        for (int i = 0; i < itemCount; i++) {
            int item = i + 1;
            buffer.put(item);
            itemsProduced++;
            System.out.println("Producer " + producerID + " produced item: " + item);

            Thread.sleep(500);
        }
        synchronized (this) {
            producersFinished++;
            if (producersFinished == itemCount) {
                notifyAll();
            }
        }
    }

    // Consume items from the buffer by the consumer
    public void consume(long consumerID, int itemCount) throws InterruptedException {
        for (int i = 0; i < itemCount; i++) {
            synchronized (this) {
                while (buffer.isEmpty() && producersFinished < itemCount) {
                    wait();
                }
                if (producersFinished == itemCount && buffer.isEmpty()) {
                    break;
                }
                int item = buffer.take();
                System.out.println("Consumer " + consumerID + " consumed item: " + item);
                Thread.sleep(500);
            }
        }
        synchronized (this) {
            if (itemsProduced == itemCount) {
                notifyAll();
            }
        }
    }
}