CS 180 - Assignment #3

Information

• Handout
• parent-matrix.c (HTML) This is a skeleton to get you started. You'll need to modify it. You can change most anything you want but don't change the print_array function because you won't diff correctly if you do. Also, you must document (Doxygenize) all functions, including main, even if you didn't write the functions.
• Command lines to compile the programs:

  gcc -D_XOPEN_SOURCE -Wall -Wextra -ansi -pedantic -O -Wno-unused-result parent-matrix.c -o parent-matrix
  gcc -D_XOPEN_SOURCE -Wall -Wextra -ansi -pedantic -O -Wno-unused-result child-matrix.c -o child-matrix
  

• To run the program, type this at the command line:

  ./parent-matrix input.txt child-matrix
  

  where the first parameter is the name of a text file that has the matrix in it and the second parameter is the name of the child program to execute.

• Sample output for a small 3x3 matrix:

         1       2       3
         4       5       6
         7       8       9
  
        30      36      42
        66      81      96
       102     126     150	
  

• Here is a program to generate random matrices for use as input for this assignment. For example, if you want a 5x5 matrix with values ranging from -20 to +20, you would run it like this:

  ./gen_matrix 5 -20 20
  

  and you would see something like this:

  5
        16      14      16      12      15
         8       8     -16     -19      -6
       -17      -2      20      11       5
       -15      -6     -10       5      19
        16      -4      16      10       5
  

  You would redirect the output into a file for use by the parent-matrix program:

  ./gen_matrix 5 -20 20 > mat5.txt
  

• Sample output for the above matrix by running: parent-matrix mat5.txt (assumes child-matrix exists)

        16      14      16      12      15
         8       8     -16     -19      -6
       -17      -2      20      11       5
       -15      -6     -10       5      19
        16      -4      16      10       5
  
       156     172     472     312     539
       653     346    -226    -387    -399
      -713    -380     130     159      91
       111    -344     -90      39     -49
      -118      80     620     544     559
  

• Sample output for a random 16x16 matrix
• Random 20x20 matrix (output20.txt)
• Matrix references:
• Refresher on matrix multiplication
• Another refresher.
• Online matrix multiplier
• Additional information about command line arguments and exec functions. These links are from a CS120 lecture.

• Using script

You need to capture your shell session that shows compiling and running the program, using diff to make sure your output is correct and running with valgrind and then running Doxygen. After you've finished coding and testing everything and are sure everything is correct, use the script command to make a text file of your session. From the bash shell in the directory you've setup to test with, run these commands: (You'll need a proper Doxygen config file called Doxyfile for the doxygen command to work. Make sure to enable warnings and set output to QUIET. Otherwise, you will have lots of unecessary output and will not be able to see the warnings.)

script
date
uptime
echo FIRSTNAME LASTNAME
pwd
whoami
uname -a
cat /proc/cpuinfo
cat /proc/meminfo
gcc -D_XOPEN_SOURCE -Wall -Wextra -ansi -pedantic -O -Wno-unused-result parent-matrix.c -o parent-matrix
gcc -D_XOPEN_SOURCE -Wall -Wextra -ansi -pedantic -O -Wno-unused-result child-matrix.c -o child-matrix
./parent-matrix mat16.txt child-matrix | tee output.txt
diff output16.txt output.txt
valgrind -q --leak-check=full --show-reachable=yes --trace-children=yes --tool=memcheck ./parent-matrix mat5.txt ./child-matrix
doxygen
ls -al html/

Then, press Ctrl-D to end the script session. A file named typescript was created with all of the commands and output. Replace FIRSTNAME and LASTNAME with your real first name and last name. This is how you get your name in the typescript file. Consult the man pages if you want more information on script.

Additional information

• Example for a 3x3 matrix:

Squaring this:

1       2       3
4       5       6
7       8       9

Results in this:

 30      36      42
 66      81      96
102     126     150

Aftering the parent creates the shared memory:



After the parent puts the width and input values into the shared memory:



Aftering each child process has written its result to the shared memory



This is the how the first child calculates the value:

Row 0:



Column 0:



Writes to first integer in the result matrix:



This is how the 6th child calculates the value:

Row 1:



Column 2:



Writes to 6th integer in the result matrix: