CS 4210, Spring 2005

Homework 1

Due 5 PM Thursday January 27, 2005

Turn in electronically (email to fujimoto@cc.gatech.edu)

1. Turn in a digital picture of yourself (head shot).

2. Write a pthreads program using the producer/consumer (work queue or work pile) model to do some simple arithmetic on numbers entered on the keyboard. Your program should take a single command line argument that indicates the number of consumer (worker) threads that should be created. After creating the worker threads, the main program should repeatedly prompt the user and read a number entered from the keyboard. This number should be placed into a queue. One of the consumer threads should then remove the number from the queue, compute the square of the number, print the result, and then go back and wait for more work to do. You may assume the queue size is bounded of some reasonable size (if the queue becomes full, the main thread should block). You may assume the program executes forever, i.e., the main program and worker threads never exit.

Notes on this assignment:

• The purpose of this assignment is to give you some practice at writing a simple pthreads code, and make sure you are set up to create and run pthreads programs. This assignment should not be very difficult. If you are spending a lot of time on this, one of us has made a mistake! So please send email if that happens.
• You are free to use and modify code discussed in class, provided you thoroughly understand what the code does!

Some suggestions in programming with pthreads:

• Compile your programs with "-lpthread" to make sure you get the right library, e.g.,

gcc –o prog prog.c –lpthread

• Be sure to test the return values of pthread calls; you might want to create wrappers around common functions so you don't forget.