[v1,7/7] rust: workqueue: add `try_spawn` helper method
Commit Message
This adds a convenience method that lets you spawn a closure for
execution on a workqueue. This will be the most convenient way to use
workqueues, but it is fallible because it needs to allocate memory.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/kernel/workqueue.rs | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
Comments
On 5/17/23 17:31, Alice Ryhl wrote:
> This adds a convenience method that lets you spawn a closure for
> execution on a workqueue. This will be the most convenient way to use
> workqueues, but it is fallible because it needs to allocate memory.
>
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> ---
> [...]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
On Wednesday, May 17th, 2023 at 22:31, Alice Ryhl <aliceryhl@google.com> wrote:
> This adds a convenience method that lets you spawn a closure for
> execution on a workqueue. This will be the most convenient way to use
> workqueues, but it is fallible because it needs to allocate memory.
>
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> ---
> rust/kernel/workqueue.rs | 40 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
> index 007005ddcaf0..303b72efd95f 100644
> --- a/rust/kernel/workqueue.rs
> +++ b/rust/kernel/workqueue.rs
> @@ -57,6 +57,42 @@ impl Queue {
> })
> }
> }
> +
> + /// Tries to spawn the given function or closure as a work item.
> + ///
> + /// This method can fail because it allocates memory to store the work item.
> + pub fn try_spawn<T: 'static + Send + Fn()>(&self, func: T) -> Result {
Why is this `Fn()` instead of `FnOnce()`?
> + let init = pin_init!(ClosureWork {
> + work <- Work::new(),
> + func: Some(func),
> + });
> +
> + self.enqueue(Box::pin_init(init)?);
> + Ok(())
> + }
> +}
> +
> +/// A helper type used in `try_spawn`.
> +#[pin_data]
> +struct ClosureWork<T> {
> + #[pin]
> + work: Work<Pin<Box<ClosureWork<T>>>>,
> + func: Option<T>,
> +}
> +
> +impl<T> ClosureWork<T> {
> + fn project(self: Pin<&mut Self>) -> &mut Option<T> {
> + // SAFETY: The `func` field is not structurally pinned.
> + unsafe { &mut self.get_unchecked_mut().func }
> + }
> +}
> +
> +impl<T: FnOnce()> BoxWorkItem for ClosureWork<T> {
> + fn run(mut self: Pin<Box<Self>>) {
> + if let Some(func) = self.as_mut().project().take() {
> + (func)()
> + }
> + }
> }
>
> /// A work item.
> @@ -280,6 +316,10 @@ macro_rules! impl_has_work {
> )*};
> }
>
> +impl_has_work! {
> + impl<T> HasWork<Pin<Box<Self>>> for ClosureWork<T> { self.work }
> +}
> +
> /// Declares that [`Arc<Self>`] should implement [`WorkItem`].
> ///
> /// # Examples
> --
> 2.40.1.606.ga4b1b128d6-goog
>
--
Cheers,
Benno
Benno Lossin <benno.lossin@proton.me> writes:
>> + /// Tries to spawn the given function or closure as a work item.
>> + ///
>> + /// This method can fail because it allocates memory to store the work item.
>> + pub fn try_spawn<T: 'static + Send + Fn()>(&self, func: T) -> Result {
>
> Why is this `Fn()` instead of `FnOnce()`?
That's a mistake. Good catch. It will be fixed in the next version.
Alice
@@ -57,6 +57,42 @@ impl Queue {
})
}
}
+
+ /// Tries to spawn the given function or closure as a work item.
+ ///
+ /// This method can fail because it allocates memory to store the work item.
+ pub fn try_spawn<T: 'static + Send + Fn()>(&self, func: T) -> Result {
+ let init = pin_init!(ClosureWork {
+ work <- Work::new(),
+ func: Some(func),
+ });
+
+ self.enqueue(Box::pin_init(init)?);
+ Ok(())
+ }
+}
+
+/// A helper type used in `try_spawn`.
+#[pin_data]
+struct ClosureWork<T> {
+ #[pin]
+ work: Work<Pin<Box<ClosureWork<T>>>>,
+ func: Option<T>,
+}
+
+impl<T> ClosureWork<T> {
+ fn project(self: Pin<&mut Self>) -> &mut Option<T> {
+ // SAFETY: The `func` field is not structurally pinned.
+ unsafe { &mut self.get_unchecked_mut().func }
+ }
+}
+
+impl<T: FnOnce()> BoxWorkItem for ClosureWork<T> {
+ fn run(mut self: Pin<Box<Self>>) {
+ if let Some(func) = self.as_mut().project().take() {
+ (func)()
+ }
+ }
}
/// A work item.
@@ -280,6 +316,10 @@ macro_rules! impl_has_work {
)*};
}
+impl_has_work! {
+ impl<T> HasWork<Pin<Box<Self>>> for ClosureWork<T> { self.work }
+}
+
/// Declares that [`Arc<Self>`] should implement [`WorkItem`].
///
/// # Examples