code19_CLASSIC_PROBLEMS_producer_consumer_problem.java

// Java program to implement solution of producer
// consumer problem.
import java.util.LinkedList;

public class Threadexample
{
	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);
				}
			}
		}
	}
}