https://raw.githubusercontent.com/vsaravanan/java22/master/src/main/java/com/saravanjs/java22/console/multithreading/semaphore/ProducerConsumerExample.java
 
 
 

class SharedBuffer {
private final Queue<Integer> buffer;
private final int maxSize;
private final Semaphore items;   // Semaphore counting available items
private final Semaphore spaces;  // Semaphore counting available spaces
private final Semaphore mutex;   // Binary semaphore for mutual exclusion

public SharedBuffer(int maxSize) {
this.buffer = new LinkedList<>();
this.maxSize = maxSize;
this.items = new Semaphore(0);
this.spaces = new Semaphore(maxSize);
this.mutex = new Semaphore(1);
    }

public void put(int item) throws InterruptedException {
spaces.acquire();  // Wait for available space
mutex.acquire();   // Ensure mutual exclusion
buffer.add(item);
mutex.release();
items.release();   // Signal that an item is available
}

public int take() throws InterruptedException {
items.acquire();   // Wait for an available item
mutex.acquire();   // Ensure mutual exclusion
int item = buffer.poll();
mutex.release();
spaces.release();  // Signal that space is available
return item;
    }
}

public class Consumer implements Runnable {
 private final SharedBuffer sharedBuffer;


 public Consumer(SharedBuffer sharedBuffer) {
 this.sharedBuffer = sharedBuffer;

    }


 @Override
 public void run() {
 while (true) {
 try {
 int item = sharedBuffer.take();
 System.out.println("Consuming " + item);
 Thread.sleep((int) (Math.random() * 1000));  // Simulate time taken to consume an item
 } catch (InterruptedException e) {
 Thread.currentThread().interrupt();
 System.out.println("Consumer was interrupted");
 break;  // Exit the loop if interrupted
 }

        }

    }

}

public class Producer implements Runnable {
 private final SharedBuffer sharedBuffer;


 public Producer(SharedBuffer sharedBuffer) {
 this.sharedBuffer = sharedBuffer;

    }


 @Override
 public void run() {
 for (int i = 0; i < 10; i++) {
 try {
 System.out.println("Producing " + i);
 sharedBuffer.put(i);
 Thread.sleep((int) (Math.random() * 1000));  // Simulate time taken to produce an item
 } catch (InterruptedException e) {
 Thread.currentThread().interrupt();
 System.out.println("Producer was interrupted");

            }

        }

    }

}

public class ProducerConsumerExample {
 public static void main(String[] args) {
 SharedBuffer sharedBuffer = new SharedBuffer(5);


 Thread producerThread = new Thread(new Producer(sharedBuffer));
 Thread consumerThread = new Thread(new Consumer(sharedBuffer));


 producerThread.start();
 consumerThread.start();


 try {
 producerThread.join();  // Wait for the producer to finish
 consumerThread.interrupt();  // Interrupt the consumer after the producer is done
 consumerThread.join();  // Wait for the consumer to finish
 } catch (InterruptedException e) {
 Thread.currentThread().interrupt();
 System.out.println("Main thread was interrupted");

        }

    }

}

Producing 0

Consuming 0

Producing 1

Consuming 1

Producing 2

Consuming 2

Producing 3

Consuming 3

Producing 4

Producing 5

Consuming 4

Consuming 5

Producing 6

Consuming 6

Producing 7

Consuming 7

Producing 8

Producing 9

Consuming 8