Assignment-2 Producer-Consumer

Operating Systems 
Assignment-2
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There are two problems in this assignment.

Problem-1: Producer-Consumer
In computing, the producer–consumer problem is a classic example of a multi-process
synchronization problem. The problem describes two processes, the producer and the
consumer, which share a common, fixed-size data buffer/queue.
• The producer’s job is to generate data, put it into the queue, and start again.
• At the same time, the consumer is consuming the data (i.e. removing it from the queue),
one piece at a time.
Problem: Using locks and condition variable, we need to make sure that the producer won’t try
to add data into buffer if it’s full and that the consumer won’t try to remove data from an
empty data buffer. You are given the implementations for the following Java files already:
• App.java
• Producer.java
• Consumer.java
You are asked to provide the producer-consumer implementation for SharedDataStore.java
using locks and condition variables.
Sample Run
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//App.java
public class App {
public static void main(String[] args) {
SharedDataStore dataStore = new SharedDataStore(5);//max capacity
Producer producer = new Producer(dataStore);
Consumer consumer = new Consumer(dataStore);
producer.start();
consumer.start();
}
}
//Producer.java
public class Producer extends Thread{
private SharedDataStore dataStore;
public Producer(SharedDataStore dataStore) {
this.dataStore = dataStore;
}
@Override
public void run() {
while(true){
Random r = new Random();
int number = r.nextInt(10);
dataStore.produce(number);
}
}
}
//Consumer.java
public class Consumer extends Thread{
private SharedDataStore dataStore;
public Consumer(SharedDataStore dataStore) {
this.dataStore = dataStore;
}
@Override
public void run() {
while(true){
dataStore.consume();
}
}
}
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//SharedDataStore.java
public class SharedDataStore {
//TODO: your code goes here
}
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Problem 2: Implement Locks in os/161
OS/161 is an incomplete operating system. Locks are not implemented in OS/161. In this
assignment, you are asked to implement the locks for OS/161. The interface for the lock
structure is defined in kern/include/synch.h. Implementation for functions is provided in
kern/threads/synch.c. You can use the implementation of semaphores as a model, but do not
build your lock implementation on top of semaphores or you will be penalized. In other words,
your lock implementation should not use sem_create(), P(), V() or any of the other functions
from the semaphore interface. OS/161 also includes test cases for locks.
You are going to complete the implementation for the following lock functions. In class, while
we were using pthread API, we called create, lock, unlock,... functions of thread API. In this
assignment, you’ll have the opportunity to write the logic behind these low level functions in
OS/161. I hope you’ll enjoy it!
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In order to test you implementation, uou are required to run test, lt1 which provided by sys161.
You should be receiving “Success” as the result of the test. A sample screenshot for running the
test is given below.
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What to Submit:
• You are asked to submit your work as a single zip file via CANVAS. Zip file will include
two folders
o Problem1: includes your work as an eclipse Java project. Please don’t forget to
put comments in your source code explaining your reasoning for the solution.
o Problem2: includes the kernel code that you updated (only the source files that
you updated), and a document with an explanation for your implementation and
with sample screenshots showing success from test-runs using OS/161.