From: Benno Lossin <[email protected]>
Add two functions `init_with` and `pin_init_with` to
`UniqueArc<MaybeUninit<T>>` to initialize the memory of already allocated
`UniqueArc`s. This is useful when you want to allocate memory check some
condition inside of a context where allocation is forbidden and then
conditionally initialize an object.
Signed-off-by: Benno Lossin <[email protected]>
---
rust/kernel/sync/arc.rs | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 4ed6329a5e5f..64b0e9d67025 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -540,6 +540,30 @@ impl<T> UniqueArc<MaybeUninit<T>> {
inner: unsafe { Arc::from_inner(inner.cast()) },
}
}
+
+ /// Initialize `self` using the given initializer.
+ pub fn init_with<E>(mut self, init: impl Init<T, E>) -> core::result::Result<UniqueArc<T>, E> {
+ // SAFETY: The supplied pointer is valid for initialization.
+ match unsafe { init.__init(self.as_mut_ptr()) } {
+ // SAFETY: Initialization completed successfully.
+ Ok(()) => Ok(unsafe { self.assume_init() }),
+ Err(err) => Err(err),
+ }
+ }
+
+ /// Pin-initialize `self` using the given pin-initializer.
+ pub fn pin_init_with<E>(
+ mut self,
+ init: impl PinInit<T, E>,
+ ) -> core::result::Result<Pin<UniqueArc<T>>, E> {
+ // SAFETY: The supplied pointer is valid for initialization and we will later pin the value
+ // to ensure it does not move.
+ match unsafe { init.__pinned_init(self.as_mut_ptr()) } {
+ // SAFETY: Initialization completed successfully.
+ Ok(()) => Ok(unsafe { self.assume_init() }.into()),
+ Err(err) => Err(err),
+ }
+ }
}
impl<T: ?Sized> From<UniqueArc<T>> for Pin<UniqueArc<T>> {
--
2.39.2
On Wed, 29 Mar 2023 22:33:53 +0000
[email protected] wrote:
> From: Benno Lossin <[email protected]>
>
> Add two functions `init_with` and `pin_init_with` to
> `UniqueArc<MaybeUninit<T>>` to initialize the memory of already allocated
> `UniqueArc`s. This is useful when you want to allocate memory check some
> condition inside of a context where allocation is forbidden and then
> conditionally initialize an object.
>
> Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
> ---
> rust/kernel/sync/arc.rs | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
> index 4ed6329a5e5f..64b0e9d67025 100644
> --- a/rust/kernel/sync/arc.rs
> +++ b/rust/kernel/sync/arc.rs
> @@ -540,6 +540,30 @@ impl<T> UniqueArc<MaybeUninit<T>> {
> inner: unsafe { Arc::from_inner(inner.cast()) },
> }
> }
> +
> + /// Initialize `self` using the given initializer.
> + pub fn init_with<E>(mut self, init: impl Init<T, E>) -> core::result::Result<UniqueArc<T>, E> {
> + // SAFETY: The supplied pointer is valid for initialization.
> + match unsafe { init.__init(self.as_mut_ptr()) } {
> + // SAFETY: Initialization completed successfully.
> + Ok(()) => Ok(unsafe { self.assume_init() }),
> + Err(err) => Err(err),
> + }
> + }
> +
> + /// Pin-initialize `self` using the given pin-initializer.
> + pub fn pin_init_with<E>(
> + mut self,
> + init: impl PinInit<T, E>,
> + ) -> core::result::Result<Pin<UniqueArc<T>>, E> {
> + // SAFETY: The supplied pointer is valid for initialization and we will later pin the value
> + // to ensure it does not move.
> + match unsafe { init.__pinned_init(self.as_mut_ptr()) } {
> + // SAFETY: Initialization completed successfully.
> + Ok(()) => Ok(unsafe { self.assume_init() }.into()),
> + Err(err) => Err(err),
> + }
> + }
> }
>
> impl<T: ?Sized> From<UniqueArc<T>> for Pin<UniqueArc<T>> {
> --
> 2.39.2
>
>
On 3/30/23 00:33, [email protected] wrote:
> From: Benno Lossin <[email protected]>
>
> Add two functions `init_with` and `pin_init_with` to
> `UniqueArc<MaybeUninit<T>>` to initialize the memory of already allocated
> `UniqueArc`s. This is useful when you want to allocate memory check some
> condition inside of a context where allocation is forbidden and then
> conditionally initialize an object.
>
> Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
I asked for this one because we will need it in the binder driver.
[email protected] writes:
> From: Benno Lossin <[email protected]>
>
> Add two functions `init_with` and `pin_init_with` to
> `UniqueArc<MaybeUninit<T>>` to initialize the memory of already allocated
> `UniqueArc`s. This is useful when you want to allocate memory check some
> condition inside of a context where allocation is forbidden and then
> conditionally initialize an object.
>
> Signed-off-by: Benno Lossin <[email protected]>
> ---
Reviewed-by: Andreas Hindborg <[email protected]>
> rust/kernel/sync/arc.rs | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
> index 4ed6329a5e5f..64b0e9d67025 100644
> --- a/rust/kernel/sync/arc.rs
> +++ b/rust/kernel/sync/arc.rs
> @@ -540,6 +540,30 @@ impl<T> UniqueArc<MaybeUninit<T>> {
> inner: unsafe { Arc::from_inner(inner.cast()) },
> }
> }
> +
> + /// Initialize `self` using the given initializer.
> + pub fn init_with<E>(mut self, init: impl Init<T, E>) -> core::result::Result<UniqueArc<T>, E> {
> + // SAFETY: The supplied pointer is valid for initialization.
> + match unsafe { init.__init(self.as_mut_ptr()) } {
> + // SAFETY: Initialization completed successfully.
> + Ok(()) => Ok(unsafe { self.assume_init() }),
> + Err(err) => Err(err),
> + }
> + }
> +
> + /// Pin-initialize `self` using the given pin-initializer.
> + pub fn pin_init_with<E>(
> + mut self,
> + init: impl PinInit<T, E>,
> + ) -> core::result::Result<Pin<UniqueArc<T>>, E> {
> + // SAFETY: The supplied pointer is valid for initialization and we will later pin the value
> + // to ensure it does not move.
> + match unsafe { init.__pinned_init(self.as_mut_ptr()) } {
> + // SAFETY: Initialization completed successfully.
> + Ok(()) => Ok(unsafe { self.assume_init() }.into()),
> + Err(err) => Err(err),
> + }
> + }
> }
>
> impl<T: ?Sized> From<UniqueArc<T>> for Pin<UniqueArc<T>> {