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| author | John van der Koijk <33966414+jvanderk@users.noreply.github.com> | 2022-02-20 19:21:25 +0100 |
|---|---|---|
| committer | Henrik Tjäder <henrik@tjaders.com> | 2023-01-25 21:07:38 +0100 |
| commit | 04189cc6844d7d43305a57464713defb5a46d85c (patch) | |
| tree | 0f9a7f77be32c1438582ccafcb45837fa949f38a /book/en/src/by-example/resources.md | |
| parent | 3240fb332a7b1b17333ac1c589b303909bde1dc9 (diff) | |
Mostly editorial review.
Diffstat (limited to 'book/en/src/by-example/resources.md')
| -rw-r--r-- | book/en/src/by-example/resources.md | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/book/en/src/by-example/resources.md b/book/en/src/by-example/resources.md index 6349b52..30089d3 100644 --- a/book/en/src/by-example/resources.md +++ b/book/en/src/by-example/resources.md @@ -30,13 +30,13 @@ task. Thus, a task `#[local]` resource can only be accessed by one singular task. Attempting to assign the same `#[local]` resource to more than one task is a compile-time error. -Types of `#[local]` resources must implement [`Send`] trait as they are being sent from `init` -to target task and thus crossing the thread boundary. +Types of `#[local]` resources must implement a [`Send`] trait as they are being sent from `init` +to a target task, crossing a thread boundary. [`Send`]: https://doc.rust-lang.org/stable/core/marker/trait.Send.html The example application shown below contains two tasks where each task has access to its own -`#[local]` resource, plus that the `idle` task has its own `#[local]` as well. +`#[local]` resource; the `idle` task has its own `#[local]` as well. ``` rust {{#include ../../../../examples/locals.rs}} @@ -49,12 +49,14 @@ $ cargo run --target thumbv7m-none-eabi --example locals {{#include ../../../../ci/expected/locals.run}} ``` +Local resources in `#[init]` and `#[idle]` have `'static` +lifetimes. This is safe since both tasks are not re-entrant. + ### Task local initialized resources -A special use-case of local resources are the ones specified directly in the resource claim, -`#[task(local = [my_var: TYPE = INITIAL_VALUE, ...])]`, this allows for creating locals which do no need to be +Local resources can also be specified directly in the resource claim like so: +`#[task(local = [my_var: TYPE = INITIAL_VALUE, ...])]`; this allows for creating locals which do no need to be initialized in `#[init]`. -Moreover, local resources in `#[init]` and `#[idle]` have `'static` lifetimes, this is safe since both are not re-entrant. Types of `#[task(local = [..])]` resources have to be neither [`Send`] nor [`Sync`] as they are not crossing any thread boundary. @@ -92,9 +94,9 @@ preempting the critical section. This synchronization protocol is known as the [srp]: https://en.wikipedia.org/wiki/Stack_Resource_Policy In the example below we have three interrupt handlers with priorities ranging from one to three. -The two handlers with the lower priorities contend for the `shared` resource and need to lock the -resource for accessing the data. The highest priority handler, which do not access the `shared` -resource, is free to preempt the critical section created by the lowest priority handler. +The two handlers with the lower priorities contend for a `shared` resource and need to succeed in locking the +resource in order to access its data. The highest priority handler, which does not access the `shared` +resource, is free to preempt a critical section created by the lowest priority handler. ``` rust {{#include ../../../../examples/lock.rs}} |