Week 10

Channels, CSP, and Go

Peter Welch's Occam-pi Lecture Notes

Go demo and starter code
- copy from Marc's directory into your cs377 course directory:
```
$ cd ~/cs377
$ cp -r /home/mlsmith/cs377-examples/Go ./
```
- you should see the following files in your local Go directory:
```
$ ls
csp-dining-phils.go phils-out.txt sieve.go sort-pump.go
$
```

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)
- To run this program:
```
$ go run 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
```

Assignment 5 posted
- Sort Pump Gophers PDF
- see a similar example in occam on slides 13–31 of PHW's replicators lecture notes
- Due: Friday, Nov 18th