One Minute Evaluations for 21-23 October 2003

CS 438 - Operating Systems Concepts

• Topic: How to deal with deadlock - preventing avoiding detection and recovery.

  Question: How to use bowls and stones to insure resource availability.

  One minute response: You can't; the only way to insure resource availability is to make sure there are enough resources on hand to cover the demand. You can do that by virtualizing the resource (as with printers), or by supplying an over-capacity (as with gHz CPUs), but sometimes it's not possible (as with messages exchanged between processes).

• Topic: This week we covered defining deadlock and techniques to prevent/avoid/detect and recover from it.

• Topic: Learned how semaphores are our friends.

  Question: Where is a good Mexican restaurant around here? Don't say Casa Comida b/c they suck.

• Topic: We learned about semaphores.

  Question: Why doesn't Java use just its own queue class to implement FIFO on the process waiting queue?

  One minute response: Thread blocking is implemented inside the Java Virtual Machine (JVM), which doesn't have to be implemented in Java.

• Topic: Deadlock avoidance; deadlock recovery and detection.

  Question: Does VxWorks use threads?

  One minute response: Yes; they provide threads rather than processes to keep down the cost of multi-tasking.

• Topic: We talked about deadlock and semaphores.

  Question: Can't think of a good question.

• Topic: Deadlock definition, deadlock identification, deadlock solution techniques - avoidance, etc; semaphores - implementation.

  Question: When you talked about Java semaphores, was that Java OS (or VM)? What is JavaOS?

  One minute response: Java semaphores are defined by the Language Reference Manual; they're implemented in the Java Virtual Machine (JVM). JavaOS is Sun's attempt to muscle in on the embedded systems market.

• Topic: Device management.

• Topic: Deadlock, semaphores.

• Topic: Semaphores, tape, and deadlock prevention avoidance, clean-up. Blocking and context switching in reference to semaphores.

  Question: What are the alternatives to semaphores?

• Topic: Deadlock, semaphores.

• Topic: Various problems with deadlock and avoiding it.

• Topic: The Baker's Algorithm.

  Question: When will the temperature be above 75 again?

• Topic: We learned about the magical and wonderful world of semaphores.

  Question: What is the meaning of life, the universe, and Everything?

This page last modified on 16 July 2003.