One Minute Evaluations for 24-26 June

CS 598 - Concurrent Programming

• Topic: Semaphores, multi-buffer, binary signaling, dining philosophers, readers-writers, baton passing, resource scheduling.

  Didn't get: Multi-buffer, multi-producer-consumer and baton passing.

  One minute response: Multi-buffer, multi-producer-consumer synchronization produces the most concurrency of all the producer-consumer variations we studied; baton passing is an efficient way for one computation to grand mutual exclusion to another computation.

• Topic: Semaphores, mutex, synchronize, read-write, producer-consumer.

• Topic: semaphores, dining philosophers, split-binary semaphores, counting semaphores, reader/writer with semaphores, passing the baton.

  Didn't get: Why first implementation of the readers-writers with semaphores was not fair.

  One minute response: The first readers-writers implementation is unfair for the same reason that the second implementation is unfair. And the second readers-writers implementation is unfair because a reader can sneak into the database before a waiting writer can. See the lecture notes for a more detailed description of the problem.

• Topic: Semaphore, binary semaphore, reader-writer with multi semaphores, buffer, multi-buffer.

  Didn't get: Pass baton implementation.

  One minute response: If you want give your friend a $5 bill, it's better to hand it to your friend directly, rather than put it on a table with a note saying it's for your friend. Handing the bill to your friend directly is baton passing.

This page last modified on 16 July 2003.