Messages in this thread Patch in this message | | | Date | Thu, 1 Jun 2023 13:49:45 +0000 | Subject | [PATCH v2 7/8] rust: workqueue: add `try_spawn` helper method | From | Alice Ryhl <> |
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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> --- 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>, -- 2.41.0.rc0.172.g3f132b7071-goog
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