public-collect/books-futures-explained
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Reworked the green threads section

Browse Source
This commit is contained in:
Carl Fredrik Samson
2022-01-26 01:05:32 +01:00
committed by GitHub
parent 00ffd295b7
commit f29048f969
1 changed files with 9 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
src/0_background_information.md
View File

@@ -91,7 +91,11 @@ Now, let's look at some other options for multitasking. They all have in common
that they implement a way to do multitasking by having a "userland" that they implement a way to do multitasking by having a "userland"
runtime. runtime.
## Green threads ## Green threads/stackful coroutines
In this book I'll use the term "green threads" to mean stackful coroutines to differentiate
them from the other continuation mechanisms described in this chapter. You can, however, see
the term "green threads" be used to describe a broader set of continuation mechanisms in different
littrature or discussions on the internet.
Green threads use the same mechanism as an OS - creating a thread for Green threads use the same mechanism as an OS - creating a thread for
each task, setting up a stack, saving the CPU's state, and jumping from one each task, setting up a stack, saving the CPU's state, and jumping from one
@@ -102,7 +106,9 @@ such a system) which then continues running a different task.
Rust had green threads once, but they were removed before it hit 1.0. The state Rust had green threads once, but they were removed before it hit 1.0. The state
of execution is stored in each stack so in such a solution there would be no of execution is stored in each stack so in such a solution there would be no
need for `async`, `await`, `Future` or `Pin`. need for `async`, `await`, `Future` or `Pin`. In many ways, green threads mimics how
an operating system facilitates concurrency, and implementing them is a great
learning experience.
**The typical flow looks like this:** **The typical flow looks like this:**
@@ -145,7 +151,7 @@ A green threads example could look something like this:
> It's not in any way meant to showcase "best practice". Just so we're on > It's not in any way meant to showcase "best practice". Just so we're on
> the same page. > the same page.
_**Press the expand icon in the top right corner to show the example code (you'll actually find a minimal implementation of green threads there)**_ _**Press the expand icon in the top right corner to show the example code (you'll actually find a minimal implementation of green threads)**_
```rust, edition2021 ```rust, edition2021
# #![feature(naked_functions)] # #![feature(naked_functions)]