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TlsScopeGuard

miniextendr_api::gc_protect::tls

Struct TlsScopeGuard

struct TlsScopeGuard {
    scope_ptr: NonNull<ProtectScope>,
}

Expand description

Execute a closure with a new protection scope as the current TLS scope.

The scope is pushed onto the thread-local stack, the closure runs, and then the scope is popped and dropped (triggering UNPROTECT(n)).

§Safety

Must be called from the R main thread.

§Example

unsafe fn my_call(x: SEXP) -> SEXP {
    tls::with_protect_scope(|| {
        let x = tls::protect(x);
        let y = tls::protect(allocate_something());
        combine(x.get(), y.get())
    })
}

Guard that pops the TLS scope stack on drop (panic-safe cleanup).

Fields§

§scope_ptr: NonNull<ProtectScope>

Trait Implementations§

impl Drop for TlsScopeGuard

fn drop(&mut self)

Executes the destructor for this type. Read more

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned. Read more

Auto Trait Implementations§

impl Freeze for TlsScopeGuard

impl !RefUnwindSafe for TlsScopeGuard

impl !Send for TlsScopeGuard

impl !Sync for TlsScopeGuard

impl Unpin for TlsScopeGuard

impl UnsafeUnpin for TlsScopeGuard

impl !UnwindSafe for TlsScopeGuard

Blanket Implementations§

impl<T> Any for T
where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T
where T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> From<T> for T

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for T
where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T> SizeEq<Cell<T>> for T
where T: ?Sized,

type CastFrom = CastFromWrapper

impl<T> SizeEq<ManuallyDrop<T>> for T
where T: ?Sized,

type CastFrom = CastFromWrapper

impl<T> SizeEq<MaybeUninit<T>> for T

type CastFrom = CastSizedExact

impl<T> SizeEq<ReadOnly<T>> for T
where T: ?Sized,

type CastFrom = CastFromReadOnly

impl<T> SizeEq<T> for T
where T: ?Sized,

type CastFrom = IdCast

impl<T> SizeEq<Unalign<T>> for T

type CastFrom = CastFromWrapper

impl<T> SizeEq<UnsafeCell<T>> for T
where T: ?Sized,

type CastFrom = CastFromWrapper

impl<T> SizeEq<Wrapping<T>> for T

type CastFrom = CastFromWrapper

impl<T> SizedTypeProperties for T

#[doc(hidden)]
const SIZE: usize = _

🔬This is a nightly-only experimental API. (sized_type_properties)

#[doc(hidden)]
const ALIGN: usize = _

🔬This is a nightly-only experimental API. (sized_type_properties)

#[doc(hidden)]
const ALIGNMENT: Alignment = _

🔬This is a nightly-only experimental API. (ptr_alignment_type)

#[doc(hidden)]
const IS_ZST: bool = _

🔬This is a nightly-only experimental API. (sized_type_properties)

true if this type requires no storage. false if its size is greater than zero. Read more

#[doc(hidden)]
const LAYOUT: Layout = _

🔬This is a nightly-only experimental API. (sized_type_properties)

#[doc(hidden)]
const MAX_SLICE_LEN: usize = _

🔬This is a nightly-only experimental API. (sized_type_properties)

The largest safe length for a [Self]. Read more

impl<T, U> TryFrom<U> for T
where U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

impl<ST, DT> CastableFrom<ST, Initialized, Initialized> for DT
where ST: ?Sized, DT: ?Sized,

impl<ST, DT> CastableFrom<ST, Uninit, Uninit> for DT
where ST: ?Sized, DT: ?Sized,

impl<T> InvariantsEq<ManuallyDrop<T>> for T
where T: ?Sized,

impl<T> InvariantsEq<T> for T
where T: ?Sized,

impl<T> InvariantsEq<Unalign<T>> for T

impl<T> InvariantsEq<Wrapping<T>> for T

impl<Src, Dst, A, SV, DV, R> MutationCompatible<Src, A, SV, DV, (BecauseRead, R)> for Dst
where A: Aliasing, SV: Validity, DV: Validity, Src: Read<A, R> + ?Sized, Dst: Read<A, R> + ?Sized,

impl<Src, Dst, A, SV, DV> MutationCompatible<Src, A, SV, DV, BecauseInvariantsEq> for Dst
where A: Aliasing, SV: Validity, DV: Validity, Src: TransmuteFrom<Dst, DV, SV> + ?Sized, Dst: TransmuteFrom<Src, SV, DV> + InvariantsEq<Src> + ?Sized,

impl<T> Read<Exclusive, BecauseExclusive> for T
where T: ?Sized,

impl<T> TransmuteFrom<Cell<T>, Valid, Valid> for T
where T: ?Sized,

impl<T> TransmuteFrom<ManuallyDrop<T>, Valid, Valid> for T
where T: ?Sized,

impl<T> TransmuteFrom<ReadOnly<T>, Valid, Valid> for T
where T: ?Sized,

impl<Src, Dst> TransmuteFrom<Src, Initialized, Initialized> for Dst
where Src: ?Sized, Dst: ?Sized,

impl<Src, Dst, V> TransmuteFrom<Src, V, Uninit> for Dst
where V: Validity, Src: ?Sized, Dst: ?Sized,

impl<Src, Dst> TransmuteFrom<Src, Valid, Initialized> for Dst
where Src: IntoBytes + ?Sized, Dst: ?Sized,

impl<T> TransmuteFrom<Unalign<T>, Valid, Valid> for T

impl<T> TransmuteFrom<UnsafeCell<T>, Valid, Valid> for T
where T: ?Sized,

impl<T> TransmuteFrom<Wrapping<T>, Valid, Valid> for T

impl<Src, Dst, A, SV, DV, C, R> TransmuteFromPtr<Src, A, SV, DV, C, R> for Dst
where A: Aliasing, SV: Validity, DV: Validity, C: CastExact<Src, Dst>, Dst: TransmuteFrom<Src, SV, DV> + TryTransmuteFromPtr<Src, A, SV, DV, C, R> + ?Sized, Src: ?Sized,

impl<Src, Dst, SV, DV, A, C, R> TryTransmuteFromPtr<Src, A, SV, DV, C, (BecauseMutationCompatible, R)> for Dst
where A: Aliasing, SV: Validity, DV: Validity, Src: TransmuteFrom<Dst, DV, SV> + ?Sized, Dst: MutationCompatible<Src, A, SV, DV, R> + ?Sized, C: CastExact<Src, Dst>,

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes