CS 3733 Operating Systems, Spring 2008 Recitation Session 6

Wednesday, February 20
This recitation will take place during the usual lecture time at 11 AM.
In this session you will become familiar with the process ring simulator that was demonstrated in class.

• Log on to your Linux Account.
• Create a rec06 directory somewhere under your cs3733 directory.
• Download this tar file and untar it into your rec06 directory.
• In that directory, execute runring. If all goes well you will have started the process ring simulator.
• Exit the simulator using the Quit in the upper right corner of the yellow window.
• Edit the file ringconfig.
  One of the lines in this file starts with user.
  Replace the name there by your name.
• Execute runring again.
• Find the Open Log button on the top of the leftmost row of buttons.
  Push this button to open a log file.
  The name of the button will change to Close Log.
• Push the Run Until Done button, a green button on the right side of the window.
• Find the Display Info button (next to the button you just pushed).
  Clicking on this brings up a window that allows you to display several things.
  Display the Output and the Gantt Chart.
• Push the following Log buttons:
  • The one at the top of the white window containing the program.
  • The Log Image button, a few buttons down from the Close Log button.
  • The Log button at the top of the Output window.
  • The Log button at the bottom right of the Gantt chart.
• Close the log file. You have created a file called logfile.html in your rec06 directory.
• Exit the simulator using the Quit button.
• Look at the log file in your browser and make sure it contains all of the logs you put in it.
• Now start the simulator again. Do not open the log file.
• This time, click on the Print Atomic button, changing it to a Print Not Atomic button.
• Use the slider below this button to change the probability (of losing the CPU after outputting a character) to 0.2. If you get close, use the Round button a few times to make it exact.
• Change the value of nprocs to 10 as follows:
  • Find the button labeled nprocs: 5.
    It is in the next to last column of buttons.
  • Click on this button. The background should change to cyan.
  • Use the backspace and number keys to change the value to 10.
  • Push return.
  • It should now say nprocs: 10 and the button below should say positions: 10
  • Note that you can only change the button while the cursor is in the button and the button background is cyan.
• Click on the size: large button so that it now says size: small
• Bring up the Output window again and run the simulator.
• Notice that the output is all jumbled up.
• Show this output window and your log file (on the screen) to the TA.