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Diffstat (limited to 'rust/kernel/types.rs')
| -rw-r--r-- | rust/kernel/types.rs | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index 9e7ca066355c..3238ffaab031 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -532,3 +532,24 @@ unsafe impl AsBytes for str {} // does not have any uninitialized portions either. unsafe impl<T: AsBytes> AsBytes for [T] {} unsafe impl<T: AsBytes, const N: usize> AsBytes for [T; N] {} + +/// Zero-sized type to mark types not [`Send`]. +/// +/// Add this type as a field to your struct if your type should not be sent to a different task. +/// Since [`Send`] is an auto trait, adding a single field that is `!Send` will ensure that the +/// whole type is `!Send`. +/// +/// If a type is `!Send` it is impossible to give control over an instance of the type to another +/// task. This is useful to include in types that store or reference task-local information. A file +/// descriptor is an example of such task-local information. +/// +/// This type also makes the type `!Sync`, which prevents immutable access to the value from +/// several threads in parallel. +pub type NotThreadSafe = PhantomData<*mut ()>; + +/// Used to construct instances of type [`NotThreadSafe`] similar to how `PhantomData` is +/// constructed. +/// +/// [`NotThreadSafe`]: type@NotThreadSafe +#[allow(non_upper_case_globals)] +pub const NotThreadSafe: NotThreadSafe = PhantomData; |