import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.locks.*;
public class ConsumerProducer {
private static Buffer buffer = new Buffer();
public static void main(String[] args) {
ExecutorService executor = Executors.newFixedThreadPool(2);
executor.execute(new ProducerTask());
executor.execute(new ConsumerTask());
executor.shutdown();
}
private static class ProducerTask implements Runnable {
@Override
public void run() {
try {
int i = 1;
while (true) {
System.out.println("Producer writes " + i);
buffer.write(i ++);
Thread.sleep((int)(Math.random() * 10000));
}
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
}
private static class ConsumerTask implements Runnable {
public void run() {
try {
while (true) {
System.out.println(" Consumer reads: " + buffer.read());
Thread.sleep((int)(Math.random() * 10000));
}
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
}
private static class Buffer {
private static final int CAPACITY = 1;
private LinkedList<Integer> queue = new LinkedList<>();
private Lock lock = new ReentrantLock();
private Condition notEmpty = lock.newCondition();
private Condition notFull = lock.newCondition();
public void write(int value) {
lock.lock();
try {
while (queue.size() == CAPACITY) {
System.out.println("Wait for notFull conditino");
notFull.await();
}
queue.offer(value);
notEmpty.signal();
} catch (InterruptedException ex) {
ex.printStackTrace();
} finally {
lock.unlock();
}
}
public int read() {
int value = 0;
lock.lock();
try {
while (queue.isEmpty()) {
System.out.println(" Wait for notEmpty condition");
notEmpty.await();
}
value = queue.poll();
notFull.signal();
} catch (InterruptedException ex) {
ex.printStackTrace();
} finally {
lock.unlock();
return value;
}
}
}
}