Download IS C362/ IS F372 (Operating Systems) Assign

Birla Institute of Technology & Science-Pilani Hyderabad Campus
CS C372/CS F372/ IS C362/ IS F372 (Operating Systems)
Assignment2
Date Assigned: 16.09.2013 Weightage: 8 Marks Date of Submission: 05.10.2013
---------------------------------Problem 1: Write a program (parent process) that takes 8 positive integers from command line
(5 odd numbers, and 3 even numbers) and displays their sum on the monitor. Then it forks a
child process. Child goes through all these 8 integers (as it has inherited all these 8 integers
from parent) and computes the sum of only the odd integers (here 5 such integers are there)
and outputs the sum onto the monitor, and further it forks another child process (grandchild of
the parent process) which sleeps for 20 seconds and then computes the sum of the even
integers (here 3 such integers are there) and outputs the sum onto the monitor. The first child
sleeps for 1 second and then exits without worrying whether its’ child (i.e. grandchild of the
parent process) is still running. Parent catches the SIGCHLD signal when the 1st child exits and
prints a message within the signal handler (“Sum of odd integers is displayed”), and then exits.
Execute your code on Ubuntu, and see if there exists a Zombie. Include screenshot of your
pstree command to show your results.
Problem 2: Write a set of programs using message queues, shared memory, fork, and exec etc.
to implement the following application (interactions between different processes and Inter
Process Communication elements are as shown below). There are two writers who read from a
Shared memory (SM) and write the contents to a message queue (MQ).
Message Queue
Dispatcher
Reader
Writer
Writer
Reader
Shared Memory
For simplicity assume that the SM contains an integer data item. The writer that gets the SM
first reads this integer and writes a message to the MQ with the data part as this integer and
type as 100. Then it increments the contents of the SM by 1 and detaches itself from the SM.
Other writer then gets attached to the SM and reads the integer (the incremented one) and
writes it to the MQ as a message with type 200. The Dispatcher process continuously reads the
MQ and invokes appropriate reader decided by the conditions given next. If the message type is
100, it executes a new program (assume /usr/bin/prog1.exe) and passes the integer data item
(referenced by the data part of the message) as the argument. Do not bother about what
prog1.exe is doing. This is one of the reader processes. If the type of the message is 200, it
instantiates a reader process that prints the integer (data part of the message) on the standard
output.
Problem 3: Create an N x N matrix with unique random values (integers) ranging from 2 to (N*N
+ 1) as its elements. The value of N should be minimum 5. Create N threads, where each thread
takes the elements of one row of the N x N matrix as its argument (one thread for each row).
Each thread looks for a prime number in its argument (row) and reports it to the master thread.
Master thread waits till all threads report back the prime numbers that are seen in their
respective rows (within the NxN matrix). Master thread then adds up (sums) these primes
numbers reported by each of the child threads (siblings). Each of thread dies or exits after
reporting the prime numbers they see in their respective rows. Master thread exits after
printing the sum. Write this program using Posix thread API (pthread_create, pthread_join,
pthread_exit, etc.)
Submission guidelines: For submission, include the application code (with executable binary)
with program numbers as the source file names. Send your files as a tar file named after one
person in your group (ID no.tar) to your respective instructor’s official mail id. You are allowed
to form a group of maximum 3 students. You need to keep your group as it was for the first
assignment. Late submissions will be rejected without being evaluated.
Cc: CSIS Dept N/B, and CMS
I/C