comprehensive-rust/src/concurrency.md

---
course: Concurrency
session: Morning
---

# Welcome to Concurrency in Rust

Rust has full support for concurrency using OS threads with mutexes and
channels.

The Rust type system plays an important role in making many concurrency bugs
compile time bugs. This is often referred to as _fearless concurrency_ since you
can rely on the compiler to ensure correctness at runtime.

<details>

- Rust lets us access OS concurrency toolkit: threads, sync. primitives, etc.
- The type system gives us safety for concurrency without any special features.
- The same tools that help with "concurrent" access in a single thread (e.g., a
  called function that might mutate an argument or save references to it to read
  later) save us from multi-threading issues.

</details>
Add course and session markers for deep-dives (#1521) This doesn't add any timing information. The authors of each deep-dive can do that separately. Fixes #1510. 2023-11-30 09:26:21 -05:00			`---`
			`course: Concurrency`
			`session: Morning`
			`---`
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file. 2023-12-31 00:15:07 +01:00
Cleanup references to "Day 4" (#603) * Align outline with new spin-off course structure With the new structure, the section on Android is a spin-off course from the main 3-day course on Rust Fundamentals. The Bare-metal and Concurrency days are spin-off courses in the same way. * Explain new course structure * Align Bare-Metal welcome page with other deep dives * Merge Day 4 page into Course Structure page * Remove Day 4 Welcome page This aligns the Concurrency in Rust section with the Bare-Metal Rust deep dive. * Show subsections for Android deep dive This aligns the Rust in Android section with the other deep dives. * Clean up welcome page and README We now cover async Rust and the course is no longer a four day course. * Remove reference to the old Day 4 * Remove Day 4 references from exercises 2023-05-02 08:02:28 +02:00			`# Welcome to Concurrency in Rust`
Publish Comprehensive Rust 🦀 2022-12-21 16:36:30 +01:00
			`Rust has full support for concurrency using OS threads with mutexes and`
			`channels.`

			`The Rust type system plays an important role in making many concurrency bugs`
Typo in "Fearless Concurrency" intro "referred to a _fearless concurrency_" -> "referred to as _fearless concurrency_" 2022-12-30 20:53:38 -08:00			`compile time bugs. This is often referred to as _fearless concurrency_ since you`
Publish Comprehensive Rust 🦀 2022-12-21 16:36:30 +01:00			`can rely on the compiler to ensure correctness at runtime.`
concurrency: Add detailed teaching notes for welcome and threads slides (#1885) These follow the flow of what I actually teach, which spends a significant amount of time on the latter slide. I think it's worthwhile to have a real flow documented in the teaching notes, both to make sure nothing gets forgotten and to structure the experience of teaching. 2024-03-06 21:11:52 +00:00
			`<details>`

			`- Rust lets us access OS concurrency toolkit: threads, sync. primitives, etc.`
			`- The type system gives us safety for concurrency without any special features.`
			`- The same tools that help with "concurrent" access in a single thread (e.g., a`
			`called function that might mutate an argument or save references to it to read`
			`later) save us from multi-threading issues.`

			`</details>`