Week 10

Channels, CSP, and Go

Last week:
- Peter Welch's Occam-pi Lecture Notes
- Go demo and starter code: see last week's notes for details
- Demo and codewalk of csp-dining-philosophers.go

Demo and codewalk: Sieve of Eratosthenes (Prime Number Sieve) sieve.go
- Go language features highlighted:
  - Only one looping construct in Go: for loop
    - all three parts are optional: init statement, conditional expression, post statement
  - channel declarations in function headers
    - can specify syntactically whether channel is for reading from:
      <-chan
      
      or writing to:
      
      chan<-
- To run this program:
```
$ go run sieve.go
```
- Monitor the running program:
  - use top command for system info while running
  - run lscpu to remind us about system resources
  - how many processes (goroutines) are running concurrently (if not in parallel)?
    - use wc -l and watch to monitor

Assignment 5 posted
- Sort Pump Gophers PDF
- see a similar example in occam on slides 13–31 of PHW's replicators lecture notes which can be found here
- be sure to read the advice section of the assignment description closely—I tried to document most of the Golang learning curve questions I encountered in the hopes of helping you!
- Due: Tue, April 14th

Linda and Tuple Space

History
- proposed by David Gelernter Wikipedia
  - while a PhD student at SUNY Stoneybrook
  - now a professor at Yale
  - overcome a great deal personally!
- origins of name
  - off-color humor
- implementations
  - C-Linda (Martin Schultz and David Gelernter)
  - Ruby implementation no less off-color!
- communications decoupled in 3 dimensions:
  - time
  - space
  - destination
Lecture Notes: PDF
Demo of Ruby/Rinda program
- from Wikipedia example:
  http://en.wikipedia.org/wiki/Rinda_(Ruby_programming_language)
  - link no longer live
- sample code: copy from my directory
```
$ cp -r /home/mlsmith/cs377-examples/rinda/ ~/cs377/
```