Trying to learn multithreading and inter-process communication of threads. Have implemented a typical producer-consumer problem. However, the output am getting is pretty sequential which should not be the case while working with threads ideally.
Ok, so here is the complete code:
public class ProducerConsumerSimulation {
public static ProducerConsumerSimulation simulation = new ProducerConsumerSimulation();
private Queue<Integer> sharedQueue = new LinkedList<Integer>();
private int MAX_LIMIT = 10;
public void produce(int i){
synchronized (sharedQueue) {
while(true){
while(sharedQueue.size()==MAX_LIMIT){
try {
sharedQueue.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
sharedQueue.add(i);
System.out.println("Produced: "+i);
sharedQueue.notifyAll();
return;
}
}
}
public void consume() {
synchronized (sharedQueue) {
while (true) {
while (sharedQueue.isEmpty()) {
try {
sharedQueue.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
int i = sharedQueue.remove();
System.out.println("Consumed: " + i);
sharedQueue.notifyAll();
return;
}
}
}
/**
* @param args
*/
public static void main(String[] args) {
for(int i=1;i<=5;i++){
Runnable p = new Producer();
Thread prod = new Thread(p);
prod.start();
}
for(int i=1;i<=5;i++){
Runnable c = new Consumer();
Thread con = new Thread(c);
con.start();
}
}
}
Producer Thread :
public class Producer implements Runnable {
/* (non-Javadoc)
* @see java.lang.Runnable#run()
*/
@Override
public void run() {
for(int i=1;i<=10;i++){
ProducerConsumerSimulation.simulation.produce(i);
}
}
}
Consumer thread:
public class Consumer implements Runnable {
/* (non-Javadoc)
* @see java.lang.Runnable#run()
*/
@Override
public void run() {
for(int i=1;i<=10;i++){
ProducerConsumerSimulation.simulation.consume();
}
}
}
Now as I run the program, producer threads are always running first than consumer. Even if I create multiple producers/consumers, result is same. Below is the output on single producer and single consumer:
Produced: 1
Produced: 2
Produced: 3
Produced: 4
Produced: 5
Produced: 6
Produced: 7
Produced: 8
Produced: 9
Produced: 10
Consumed: 1
Consumed: 2
Consumed: 3
Consumed: 4
Consumed: 5
Consumed: 6
Consumed: 7
Consumed: 8
Consumed: 9
Consumed: 10
Can somebody explain the behavior here? I have gone through many answers here but want to understand if I have wrongly implemented or else.
