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authorWedson Almeida Filho <wedsonaf@gmail.com>2022-12-28 06:03:41 +0000
committerMiguel Ojeda <ojeda@kernel.org>2023-01-16 22:20:18 +0100
commit53528772fb5a174c8606cdf0047ac4899ce05be7 (patch)
tree0d307da0adaab9a81d0579f88c379db967cdf6c9 /rust
parent9dc04365500340e6d60a996333d562af747337b1 (diff)
rust: sync: allow type of `self` to be `Arc<T>` or variants
This allows associated functions whose `self` argument has `Arc<T>` or variants as their type. This, in turn, allows callers to use the dot syntax to make calls. Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Acked-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/kernel/lib.rs1
-rw-r--r--rust/kernel/sync/arc.rs28
2 files changed, 29 insertions, 0 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index ace064a3702a..1a10f7c0ddd9 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -14,6 +14,7 @@
#![no_std]
#![feature(allocator_api)]
#![feature(core_ffi_c)]
+#![feature(receiver_trait)]
// Ensure conditional compilation based on the kernel configuration works;
// otherwise we may silently break things like initcall handling.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 22290eb5ab9b..e2eb0e67d483 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -57,6 +57,31 @@ use core::{marker::PhantomData, ops::Deref, ptr::NonNull};
///
/// // The refcount drops to zero when `cloned` goes out of scope, and the memory is freed.
/// ```
+///
+/// Using `Arc<T>` as the type of `self`:
+///
+/// ```
+/// use kernel::sync::Arc;
+///
+/// struct Example {
+/// a: u32,
+/// b: u32,
+/// }
+///
+/// impl Example {
+/// fn take_over(self: Arc<Self>) {
+/// // ...
+/// }
+///
+/// fn use_reference(self: &Arc<Self>) {
+/// // ...
+/// }
+/// }
+///
+/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
+/// obj.use_reference();
+/// obj.take_over();
+/// ```
pub struct Arc<T: ?Sized> {
ptr: NonNull<ArcInner<T>>,
_p: PhantomData<ArcInner<T>>,
@@ -68,6 +93,9 @@ struct ArcInner<T: ?Sized> {
data: T,
}
+// This is to allow [`Arc`] (and variants) to be used as the type of `self`.
+impl<T: ?Sized> core::ops::Receiver for Arc<T> {}
+
// SAFETY: It is safe to send `Arc<T>` to another thread when the underlying `T` is `Sync` because
// it effectively means sharing `&T` (which is safe because `T` is `Sync`); additionally, it needs
// `T` to be `Send` because any thread that has an `Arc<T>` may ultimately access `T` directly, for