CS 370 Spring 2009
Honors Contract: Racing Sorts
Dr. Andrew R. Dalton
March 23rd, 2009
1 Introduction
For this assignment, you will implement a multithreaded C program that visualizes the differences in running
times among a set of sorting algorithms. You will use the pthread library for multithreading and the termcap
library for low-level terminal control.
POSIX threads (pthreads) is a POSIX standard for threads. The standard defines an API for creating and
manipulating threads. Pthreads are most commonly used on Unix-like POSIX systems such as Linux and
Solaris, but Microsoft Windows implementations also exist.
Termcap is an old, low-level facility that abstracts the description and use of computer terminal devices. In
the past, terminals were more than windows on the screen, they were physical hardware devices. Operating
systems controlled these terminals by sending special text control codes. Each terminal type had (potentially)
different control codes for various operations. Termcap defines a set of attributes, including booleans (does
the terminal have this property or function?), numbers (how many rows and how many columns?), and strings
(what byte sequence do you send to make the terminal do ...?). The facility includes a terminal description
“database” and a collection of functions to get and use the information. Read the curs termcap(3x) and
termcap(5) manual pages for more information.
2 Overview
The purpose of this assignment is two-fold: to give you experience writing multithreaded applications and to
give you experience working with low-level character devices. You will develop a C program that consists of
multiple modules (read “source files”). Each module encapsulates a specific “concern” of the application. I
have provided you with 12 files: a Makefile, 3 header files, and 8 C source files. Embedded within these files
are comments marked with the string TODO. You are to fill in the implementation details for each of these
comments. These implementation details will include (not necessarily in this order):
1. The introduction of a bounded (i.e., “fixed size”) buffer that is shared among the threads in your
program. This buffer will be used to enable sorting threads to communicate with the main thread. This
bounded buffer should be implemented as an abstract data type, with all mutex locking and unlocking
code implemented within the ADT. You may use any of the examples we’ve discussed in class for this
portion of the assignment.
2. The creation of a mapping from string to sort thread entry function. This mapping will be used to
“lookup” sorting algorithms by their name.
3. The development of a simple “screen” library using termcap. You will make calls to functions in the
termcap library to lookup information about your terminal type and provide functions for accessing and
using that information. This will be contained within screen.c.
The screen library will use the ioctl() system call to retrieve and set parameters associated with the
character device associated with the terminal. See man 2 ioctl for information about the ioctl() system
call and man tty ioctl about specifics related to getting and setting terminal attributes. You will be
interested in TCGETA and TCSETA.
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