Homework 8

22C:116, Fall 1995

Due Friday Oct. 20, 1995, in class

1. Background: Figure 9-13 on page 385 in Tannenbaum's Modern Operating Systems is an oversimplification of reality.

   Part A: Give a good reason to include more than one copy of the operating system in a multiprocessor system, and a good reason why it might be useful to have multiple run-queues in such a system.

   Part B: What system models are able to support shared files, what system models are able to support messages, and why or why not?

2. Background: Transparency, as discussed in section 9.4.1, applies not only to issues of distribution, but to other issues as well.

   Part A: How does the notion of transparency apply to virtual memory systems?

   Part B: Relate the definition of transparency, as used by Tannenbaum, to the commonplace English definition of the word, and having done this, come up with a definition for the term opacity in the operating system context.

3. Background: After reading section 10.1 in Tannenbaum, go back and examine problem 4 and problem 2 part C of the midterm exam.

   The Problem: In what way is the notion of protocol hierarchy applicable to a uniprocessor operating system? In what way is it inapplicable?