episode.yml

number: 9
title: Go vs Rust - Concurrency and Race Conditions
id: B5xYBrxVSiE
intro: It's hard to put into words what I like about Rust. Easier to show with a quick example about concurrency and borrowing.
details: > 
    Capturing the "Magic of Rust" is not easy. Luckily, I found a simpler
    way: show how Rust prevents race-conditions and guides us towards a safe,
    idiomatic solution. We will port  a little Go CLI tool to Rust and compare
    both solutions in terms of safety, error handling, and concurrency patterns.
keywords:
  - race-conditions
  - ownership
  - mutex
  - concurrency
  - rayon
  - golang
  - rustlang
notes:
  - "Go in Practice book by Matt Butcher and Matt Farina (Manning Publications, 2016): https://www.manning.com/books/go-in-practice"
  - "Go in Practice example source code:
  https://github.com/Masterminds/go-in-practice"
  - "Golang provides tooling to help detect race conditions. E.g. try `go run --race` (see 'Go in Practice, p.70')"
  - "Explanation of the Rustlang race-condition prevention: https://stackoverflow.com/questions/30559073/cannot-borrow-captured-outer-variable-in-an-fn-closure-as-mutable"
  - "Amazing article about Rustlang iterator patterns by Karol Kuczmarski:
  http://xion.io/post/code/rust-iter-patterns.html"
  - "for_each method:
  https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.for_each"
  - "[std::sync::Mutex](https://doc.rust-lang.org/std/sync/struct.Mutex.html)"
  - "Golang sync.Waitgroup: https://golang.org/pkg/sync/#WaitGroup"
  - "rayon crate for easy parallelism: https://github.com/rayon-rs/rayon"
  - "partition method: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.partition"
errata:
  - "[killercup](https://github.com/killercup) added [an alternative approach](https://github.com/hello-rust/show/pull/45) that creates one hashmap per file and uses Rayon's reduce to unify them."
  - "[euantorano](https://github.com/euantorano) provided [an alternative Go approach to counting words](https://github.com/hello-rust/show/pull/46)."
  - |
      [killercup](https://github.com/killercup) added [benchmarks](https://github.com/hello-rust/show/pull/48) because <s>he seems to have too much free time at his hands</s> he was curios and people kept asking.
          Here's a quick preview (but also run them on your own machine!):
          
          ![](https://cdn.rawgit.com/hello-rust/show/a8de0d77a8cb2672fe1f37f4d9251950038b7b50/episode/9/bench/results/ep9-violin.svg)
metas:
  - "Color scheme: JetJet Alternate for VSCode"
licenses:
  - "Comedic Boing, A.wav by InspectorJ (www.jshaw.co.uk) of Freesound.org"
  - "Using 188709__setuniman__thoughts-1a37 by Setuniman (https://freesound.org/people/Setuniman/packs/9857/)"
  - "Yay sound by jbeetle https://freesound.org/people/jbeetle/sounds/274510/"
  - "piano-improv-prog-clumsy-raucous.wav by newagesoup https://freesound.org/people/newagesoup/sounds/341352/" 
  - "[Crayon designed by Terdpongvector](https://www.freepik.com/free-vector/school-stuff-collection_1060700.htm)"
chapters:
  - "1:28 Golang code"
  - "5:41 Trying to run our concurrent Go code"
  - "8:31 What I don't like about concurrent Go code"
  - "9:38 Rust code"
  - "15:36 From sequential to concurrent code"
  - "23:23 The beauty of Rust"
  - "28:05 Handling errors in for_each"