====== Week 9 ======

~~NOTOC~~


===== Assignment: Dining Java Philosophers =====

  * Assign 4, due Wed, Apr 3, 11:59pm 
    * or do you need an extension? 
    * questions?

===== Monitors =====
  * Ben-Ari slides: {{courses:cs377-201301:slides.pdf|PDF}}
    * slide 7.6 (p. 165)
  * My monitor notes: {{:courses:cs377-201603:cs377-monitors.pdf|PDF}}
  * Class participation with monitors:
    * The One-Lane Bridge problem:<code text>
Cars coming from the north and south arrive at a 
one-lane bridge. Cars heading in the same direction 
can cross the bridge at the same time, but cars 
heading in opposite directions cannot.</code>
    * can we find a way to be safe, fair, and efficient?
    * {{onelanebridgemonitor.pdf|PDF}} (with thanks to Charlie Hughes!)

===== Channels =====

  * CSP and Go!
  * Hoare's 1978 CSP paper: https://spinroot.com/courses/summer/Papers/hoare_1978.pdf
    * Go implementation of examples from paper: https://godoc.org/github.com/thomas11/csp
  * Rob Pike's Google I/O 2012 - Go Concurrency Patterns: https://youtu.be/f6kdp27TYZs
  * Peter Welch's slides introducing CSP and occam-pi (but we will use Go this semester!)
    * [[courses:cs377-201951:welch-lectures:top|Occam-pi Lecture Notes]]
    * Next time: **//Objects Considered Harmful//** (slide 27 of motivation.pdf slides)
  * Demo and codewalk of csp-dining-philosophers.go
    * Go language features highlighted:
      * channels
      * select
    * Design basis for solution in Go: go routines (processes)
      * room (communicates with philosophers over channels)
        * for philosophers to enter/leave -- at most 4 at a time to prevent deadlocking, 5th philosopher blocks 
      * forks (communicate with philosophers over channels)
      * philosophers (communicate with forks over channels)