Messages in this thread | | | Date | Thu, 30 Mar 2023 15:41:35 +0000 | From | Benno Lossin <> | Subject | Re: [PATCH v3 07/13] rust: init: add `PinnedDrop` trait and macros |
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On 30.03.23 13:01, Gary Guo wrote: > On Wed, 29 Mar 2023 22:33:24 +0000 > y86-dev@protonmail.com wrote: > >> From: Benno Lossin <y86-dev@protonmail.com> >> >> The `PinnedDrop` trait that facilitates destruction of pinned types. >> It has to be implemented via the `#[pinned_drop]` macro, since the >> `drop` function should not be called by normal code, only by other >> destructors. It also only works on structs that are annotated with >> `#[pin_data(PinnedDrop)]`. >> >> Co-developed-by: Gary Guo <gary@garyguo.net> >> Signed-off-by: Gary Guo <gary@garyguo.net> >> Signed-off-by: Benno Lossin <y86-dev@protonmail.com> >> --- >> rust/kernel/init.rs | 111 ++++++++++++++ >> rust/kernel/init/__internal.rs | 15 ++ >> rust/kernel/init/macros.rs | 263 +++++++++++++++++++++++++++++++++ >> rust/macros/lib.rs | 49 ++++++ >> rust/macros/pinned_drop.rs | 49 ++++++ >> 5 files changed, 487 insertions(+) >> create mode 100644 rust/macros/pinned_drop.rs >> >> diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs >> index 692942a008b3..4a3c7bf27a06 100644 >> --- a/rust/kernel/init/__internal.rs >> +++ b/rust/kernel/init/__internal.rs >> @@ -132,3 +132,18 @@ impl<T: ?Sized> Drop for DropGuard<T> { >> } >> } >> } >> + >> +/// Token used by `PinnedDrop` to prevent calling the function without creating this unsafely >> +/// created struct. This is needed, because the `drop` function is safe, but should not be called >> +/// manually. >> +pub struct OnlyCallFromDrop(()); >> + >> +impl OnlyCallFromDrop { >> + /// # Safety >> + /// >> + /// This function should only be called from the [`Drop::drop`] function and only be used to >> + /// delegate the destruction to the pinned destructor [`PinnedDrop::drop`] of the same type. >> + pub unsafe fn create() -> Self { > > Although this is impl detail and the name doesn't really matter, but I > am wondering why this is called `create` instead of just `new`. Not really a good reason, I associate `new()` with 'unburdened' creation (i.e. a safe function). Will change this.
-- Cheers, Benno
> >> + Self(()) >> + } >> +}
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