Messages in this thread | | | Date | Wed, 24 May 2023 14:52:50 +0000 | From | Benno Lossin <> | Subject | Re: [PATCH v1 7/7] rust: workqueue: add `try_spawn` helper method |
| |
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
| |