Assignment 1: Fun with Threads

The Royal Society for Putting Little Numbers in Front of Big Numbers has decided that it is imperative to sort large files of double precision IEEE-754 floating point data. For this, they have contacted you to write a sorting program this purpose---mostly because no one else was around and you didn't seem to be particular busy.

Your task is simple. Write a program that reads the file "/scratch1/numbers", sorts them in ascending order, and writes them back to a file "sorted". You must do this on schlitz.cs.uchicago.edu, a 4 processor Sun server. Moreover, your program should use threads to make the program run as fast as possible.

Here are a few specific details:

• The file /scratch1/numbers contains IEEE-754 double precision floating point numbers stored in binary format. This is the same type as C "double".

• Your program must be written in C or C++ and use either Solaris threads or POSIX threads. Look at the man pages for thr_create() or pthread_create() for some details and pointers.

• You may use the C qsort() function if you think it will help.

• You may not have enough disk space in your home directory to write the output file in this assignment. If not, just make a directory for yourself on either /scratch1 or /scratch2 and run the program there.

• Grading is simple. Whoever has the fastest program (wall-clock time) gets 100%. Your grade will be determined by the speed of your program relative to the fastest solution (i.e., twice as slow = 50%).

• Good luck :-).