[PATCH v2 1/2] rust: arc: rename `ArcInner` to `WithRef`

From: Wedson Almeida Filho
Date: Sat Sep 23 2023 - 10:50:00 EST


From: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>

This is in preparation for removing `ArcBorrow` and making `WithRef`
public.

This is a pure name change with no functional changes intended.

Suggested-by: Björn Roy Baron <bjorn3_gh@xxxxxxxxxxxxxx>
Signed-off-by: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
---
rust/kernel/sync/arc.rs | 20 ++++++++++----------
rust/kernel/sync/arc/std_vendor.rs | 4 ++--
2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 3d496391a9bd..86bff1e0002c 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -126,13 +126,13 @@
/// # Ok::<(), Error>(())
/// ```
pub struct Arc<T: ?Sized> {
- ptr: NonNull<ArcInner<T>>,
- _p: PhantomData<ArcInner<T>>,
+ ptr: NonNull<WithRef<T>>,
+ _p: PhantomData<WithRef<T>>,
}

#[pin_data]
#[repr(C)]
-struct ArcInner<T: ?Sized> {
+struct WithRef<T: ?Sized> {
refcount: Opaque<bindings::refcount_t>,
data: T,
}
@@ -164,7 +164,7 @@ impl<T> Arc<T> {
/// Constructs a new reference counted instance of `T`.
pub fn try_new(contents: T) -> Result<Self, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
- let value = ArcInner {
+ let value = WithRef {
// SAFETY: There are no safety requirements for this FFI call.
refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
data: contents,
@@ -201,13 +201,13 @@ pub fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
}

impl<T: ?Sized> Arc<T> {
- /// Constructs a new [`Arc`] from an existing [`ArcInner`].
+ /// Constructs a new [`Arc`] from an existing [`WithRef`].
///
/// # Safety
///
/// The caller must ensure that `inner` points to a valid location and has a non-zero reference
/// count, one of which will be owned by the new [`Arc`] instance.
- unsafe fn from_inner(inner: NonNull<ArcInner<T>>) -> Self {
+ unsafe fn from_inner(inner: NonNull<WithRef<T>>) -> Self {
// INVARIANT: By the safety requirements, the invariants hold.
Arc {
ptr: inner,
@@ -243,7 +243,7 @@ fn into_foreign(self) -> *const core::ffi::c_void {
unsafe fn borrow<'a>(ptr: *const core::ffi::c_void) -> ArcBorrow<'a, T> {
// SAFETY: By the safety requirement of this function, we know that `ptr` came from
// a previous call to `Arc::into_foreign`.
- let inner = NonNull::new(ptr as *mut ArcInner<T>).unwrap();
+ let inner = NonNull::new(ptr as *mut WithRef<T>).unwrap();

// SAFETY: The safety requirements of `from_foreign` ensure that the object remains alive
// for the lifetime of the returned value.
@@ -376,7 +376,7 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
/// # Ok::<(), Error>(())
/// ```
pub struct ArcBorrow<'a, T: ?Sized + 'a> {
- inner: NonNull<ArcInner<T>>,
+ inner: NonNull<WithRef<T>>,
_p: PhantomData<&'a ()>,
}

@@ -406,7 +406,7 @@ impl<T: ?Sized> ArcBorrow<'_, T> {
/// Callers must ensure the following for the lifetime of the returned [`ArcBorrow`] instance:
/// 1. That `inner` remains valid;
/// 2. That no mutable references to `inner` are created.
- unsafe fn new(inner: NonNull<ArcInner<T>>) -> Self {
+ unsafe fn new(inner: NonNull<WithRef<T>>) -> Self {
// INVARIANT: The safety requirements guarantee the invariants.
Self {
inner,
@@ -526,7 +526,7 @@ pub fn try_new(value: T) -> Result<Self, AllocError> {
/// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
pub fn try_new_uninit() -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
- let inner = Box::try_init::<AllocError>(try_init!(ArcInner {
+ let inner = Box::try_init::<AllocError>(try_init!(WithRef {
// SAFETY: There are no safety requirements for this FFI call.
refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
data <- init::uninit::<T, AllocError>(),
diff --git a/rust/kernel/sync/arc/std_vendor.rs b/rust/kernel/sync/arc/std_vendor.rs
index a66a0c2831b3..4b30e5597ba5 100644
--- a/rust/kernel/sync/arc/std_vendor.rs
+++ b/rust/kernel/sync/arc/std_vendor.rs
@@ -5,7 +5,7 @@
//! "Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
//! see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.

-use crate::sync::{arc::ArcInner, Arc};
+use crate::sync::{arc::WithRef, Arc};
use core::any::Any;

impl Arc<dyn Any + Send + Sync> {
@@ -17,7 +17,7 @@ pub fn downcast<T>(self) -> core::result::Result<Arc<T>, Self>
if (*self).is::<T>() {
// SAFETY: We have just checked that the type is correct, so we can cast the pointer.
unsafe {
- let ptr = self.ptr.cast::<ArcInner<T>>();
+ let ptr = self.ptr.cast::<WithRef<T>>();
core::mem::forget(self);
Ok(Arc::from_inner(ptr))
}
--
2.34.1