CS 3733 Operating Systems, Fall 2003 Recitation Session 5

Week of September 29.
In this session you will become familiar with the process ring simulator that was demonstrated in class on Thursday, September 25.

• Log on to your account in the Linux Lab.
• Create a rec05 directory somewhere under your cs3733 directory.
• Download this tar file and untar it into your rec05 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 rec05 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.