Messages in this thread | | | From | "Andreas Hindborg (Samsung)" <> | Subject | Re: [PATCH v2 7/8] rust: workqueue: add `try_spawn` helper method | Date | Fri, 02 Jun 2023 16:43:33 +0200 |
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Alice Ryhl <aliceryhl@google.com> writes:
> 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. > > Co-developed-by: Gary Guo <gary@garyguo.net> > Signed-off-by: Gary Guo <gary@garyguo.net> > Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg (Samsung) <nmi@metaspace.dk>
> --- > rust/kernel/workqueue.rs | 43 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 43 insertions(+) > > diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs > index f06a2f036d8b..c302e8b8624b 100644 > --- a/rust/kernel/workqueue.rs > +++ b/rust/kernel/workqueue.rs > @@ -29,6 +29,7 @@ > //! C header: [`include/linux/workqueue.h`](../../../../include/linux/workqueue.h) > > use crate::{bindings, prelude::*, sync::Arc, types::Opaque}; > +use alloc::alloc::AllocError; > use alloc::boxed::Box; > use core::marker::{PhantomData, PhantomPinned}; > use core::pin::Pin; > @@ -87,6 +88,44 @@ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput > }) > } > } > + > + /// 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 + FnOnce()>(&self, func: T) -> Result<(), AllocError> { > + let init = pin_init!(ClosureWork { > + work <- Work::new(), > + func: Some(func), > + }); > + > + self.enqueue(Box::pin_init(init).map_err(|_| AllocError)?); > + Ok(()) > + } > +} > + > +/// A helper type used in `try_spawn`. > +#[pin_data] > +struct ClosureWork<T> { > + #[pin] > + work: Work<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()> WorkItem for ClosureWork<T> { > + type Pointer = Pin<Box<Self>>; > + > + fn run(mut this: Pin<Box<Self>>) { > + if let Some(func) = this.as_mut().project().take() { > + (func)() > + } > + } > } > > /// A raw work item. > @@ -325,6 +364,10 @@ unsafe fn raw_get_work(ptr: *mut Self) -> *mut $crate::workqueue::Work<$work_typ > )*}; > } > > +impl_has_work! { > + impl<T> HasWork<Self> for ClosureWork<T> { self.work } > +} > + > unsafe impl<T, const ID: u64> WorkItemPointer<ID> for Arc<T> > where > T: WorkItem<ID, Pointer = Self>,
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