CS 110 Operating Systems
Notes to the Grader!!

What follows is the grading sheet for the Barber Shop Priority Project.

  1. Do not attempt to read any code. They should not provide any.... If the comments are incomplete, then it is their problem.
  2. Since the only real change from the Basic Barber Shop Project involves the handling of counting haircuts and rearranging the queues, the question is how did they do this. I believe that either immediately after a haircut or immediately before a haircut, the barber either does the job or through semaphores controls a process that does all the counting and updating. There are various arguments as to exactly when this happens, but I would think the ideal case is just after a haircut. But if people make other choices, then they only need to write a reasonable justification for those choices. I do not think there is a single approach, rather people should be able to describe their approach and implement it well.
  3. Look at the output and follow the Queue changes for each of the input files.

Input Files:

  1. input1 -
    • consumer sleep = 45
    • print shop contents
    • producer sleep = 3
    • Demonstrates: general working; only officers and grunts. should see grunts move up in the queue once hair cutting starts. Grunts will move as a group because haircuts, NOT time is the priority mechanism, and the delay in starting will make all grunts wait the same number of hair cuts.
    • Highlight: Each Grunt entry into Barber Shop and each grunt movement between queues.

  2. input2 -
    • consumer sleep = 30
    • print shop contents
    • producer sleep = 2
    • Demonstrates: tests priority movement between queues; there will be multiple moves.
    • Highlight: Each Grunt entry into Barber Shop and each grunt movement between queues.
    • I have not really thought about how this will work for this input file, so as you grade you might tell me what exactly happens

    Implementation Evaluation:

    The following grading criteria will be used.
    • 20 points total.
      • 5 Points
        The usual commented introduction with emphasis on the following new material:
        • Implementation of how haircut counting and grunt movement is done.
      • 15 Points
        • Performance on input1
        • Performance on input2
    Last modified Dec 14, 01 by mike@cs.hmc.edu