CSIS3530 Operating Systems Fall 2009

ASSIGNMENT NO. 2 (Deadline: Tuesday, Sept 8)

MULTI-PROGRAMMING

Study the behavior of a batch system with multi-programming.
The following simulation models use psim3. 

File: batchmio.cpp

As before, copy this model file from /home/jgarrido/psim3 on CS3.

This model reads all input parameters from console input; default values are displayed.
Run the simulation models with the default values by typing zero "0" on each input parameter. 
Type any alpha character (a-z, A-Z) to start the simulation.
The output of the simulation run is stored in files: "batchmio.dat" and "resources.dat".
Rename these files appropriately so they will not be over-written by the next simulation run.

The default value of the degree of multi-programming is 15. Run the simulation model again with the degree of multi-programming set to 1 (no multi-programming). 
Compare the performance of the two simulation run. 

Write your report following the guidelines given. In the last part of your report include your answers to the questions that follow.


1. What are the main differences between this model and the previous model (assignment #1 batch.cpp)?
2. With no multiprogramming, is the input queue needed? Why is the ready queue needed? 
3. What aspect of an operating system is the model representing? 
4. What performance measures does the model compute? 
5. After changing some of the parameters in the model and executing again the model: 
a. What changes in the results do you notice? 
b. What other performance measures can this model compute?