Struct abi_stable::std_types::RArc

#[repr(C)]
pub struct RArc<T> { /* fields omitted */ }

Ffi-safe version of std::sync::Arc

Example

Using an RArc<RMutex<RVec<u32>>> to get a list populated from multiple threads.

use abi_stable::{
    external_types::RMutex,
    std_types::{RArc, RVec},
};

use std::thread;

let arc = RArc::new(RMutex::new(RVec::new()));

{
    let arc2 = RArc::clone(&arc);
    assert!(std::ptr::eq(&*arc, &*arc2));
}

let mut guards = Vec::new();

for i in 0..10_u64 {
    let arc = RArc::clone(&arc);
    guards.push(thread::spawn(move || {
        for j in 0..100_u64 {
            arc.lock().push(i * 100 + j);
        }
    }));
}

for guard in guards {
    guard.join().unwrap();
}

let mut vec = RArc::try_unwrap(arc)
    .ok()
    .expect("All the threads were joined, so this must be the only RArc")
    .into_inner();

vec.sort();

assert_eq!(vec, (0..1000).collect::<RVec<_>>());

Implementations

impl<T> RArc<T>

pub fn new(this: T) -> Self

Constructs an RArc from a value.

Example

use abi_stable::std_types::RArc;

let arc = RArc::new(100);

pub fn into_arc(this: Self) -> Arc<T> where
    T: Clone, 

Converts this RArc<T> into an Arc<T>

Allocators

RArc<T> cannot always be converted to an Arc<T>, because their allocators might be different.

When is T cloned

T is cloned if the current dynamic_library/executable is not the one that created the RArc<T>, and the strong count is greater than 1.

Example

use abi_stable::std_types::RArc;
use std::sync::Arc;

let arc = RArc::new(100);

assert_eq!(RArc::into_arc(arc), Arc::new(100));

pub fn try_unwrap(this: Self) -> Result<T, Self>

Attempts to unwrap this RArc<T> into a T, returns Err(self) if the RArc<T>’s strong count is greater than 1.

Example

use abi_stable::std_types::RArc;

let arc0 = RArc::new(100);
assert_eq!(RArc::try_unwrap(arc0), Ok(100));

let arc1 = RArc::new(100);
let arc1_clone = RArc::clone(&arc1);
assert_eq!(RArc::try_unwrap(arc1), Err(arc1_clone.clone()));

pub fn get_mut(this: &mut Self) -> Option<&mut T>

Attempts to create a mutable reference to T, failing if the RArc<T>’s strong count is greater than 1.

Example

use abi_stable::std_types::RArc;

let mut arc0 = RArc::new(100);
*RArc::get_mut(&mut arc0).unwrap() += 400;
assert_eq!(*arc0, 500);

let mut arc1 = RArc::new(100);
let _arc1_clone = RArc::clone(&arc1);
assert_eq!(RArc::get_mut(&mut arc1), None);

pub fn make_mut(this: &mut Self) -> &mut T where
    T: Clone, 

Makes a mutable reference to T.

If there are other RArc<T>s pointing to the same value, then T is cloned into a new RArc<T> to ensure unique ownership of the value.

Postconditions

After this call, the strong count of this will be 1, because either it was 1 before the call, or because a new RArc<T> was created to ensure unique ownership of T.

Example

use abi_stable::std_types::RArc;

let mut arc0 = RArc::new(100);
*RArc::make_mut(&mut arc0) += 400;
assert_eq!(*arc0, 500);

let mut arc1 = RArc::new(100);
let arc1_clone = RArc::clone(&arc1);
*RArc::make_mut(&mut arc1) += 400;
assert_eq!(*arc1, 500);
assert_eq!(*arc1_clone, 100);

pub fn strong_count(this: &Self) -> usize

Gets the number of RArc that point to the value.

Example

use abi_stable::std_types::RArc;

let arc = RArc::new(0);
assert_eq!(RArc::strong_count(&arc), 1);

let clone = RArc::clone(&arc);
assert_eq!(RArc::strong_count(&arc), 2);

pub fn weak_count(this: &Self) -> usize

Gets the number of std::sync::Weak that point to the value.

Example

use abi_stable::std_types::RArc;

use std::sync::Arc;

let rustarc = Arc::new(0);
let arc = RArc::from(rustarc.clone());
assert_eq!(RArc::weak_count(&arc), 0);

let weak_0 = Arc::downgrade(&rustarc);
assert_eq!(RArc::weak_count(&arc), 1);

let weak_1 = Arc::downgrade(&rustarc);
assert_eq!(RArc::weak_count(&arc), 2);

Trait Implementations

impl<T> AsPtr for RArc<T>

fn as_ptr(&self) -> *const T

Gets a const raw pointer to the value that this points to.

fn as_rref(&self) -> RRef<'_, Self::PtrTarget>

Converts this pointer to an RRef.

impl<T> AsRef<T> for RArc<T>

fn as_ref(&self) -> &T

Performs the conversion.

impl<T> Borrow<T> for RArc<T>

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<T, O> CanTransmuteElement<O> for RArc<T>

type TransmutedPtr = RArc<O>

The type of the pointer after it’s element type has been changed.

unsafe fn transmute_element_(self) -> Self::TransmutedPtr

Transmutes the element type of this pointer..

impl<T> Clone for RArc<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for RArc<T> where
    T: Debug, 

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for RArc<T> where
    T: Default, 

fn default() -> Self

Returns the “default value” for a type.

impl<T> Deref for RArc<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'de, T> Deserialize<'de> for RArc<T> where
    T: Deserialize<'de>, 

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<T> Display for RArc<T> where
    T: Display, 

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Drop for RArc<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> From<Arc<T>> for RArc<T>

fn from(this: Arc<T>) -> RArc<T>

Performs the conversion.

impl<T> From<RArc<T>> for Arc<T> where
    T: Clone + StableAbi, 

fn from(this: RArc<T>) -> Arc<T>

Performs the conversion.

impl<T> GetPointerKind for RArc<T>

type Kind = PK_SmartPointer

The kind of the pointer.

type PtrTarget = T

What this pointer points to.

const KIND: PointerKind

The value-level version of the Kind associated type.

impl<T> GetStaticEquivalent_ for RArc<T> where
    T: __StableAbi, 

type StaticEquivalent = _static_RArc<__GetStaticEquivalent<T>>

impl<T> Hash for RArc<T> where
    T: Hash, 

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T> IntoReprRust for RArc<T> where
    T: Clone + StableAbi, 

type ReprRust = Arc<T>

The #[repr(Rust)] equivalent.

fn into_rust(self) -> Self::ReprRust

Performs the conversion

impl<T> Ord for RArc<T> where
    T: Ord, 

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T> PartialEq<RArc<T>> for RArc<T> where
    T: PartialEq, 

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T> PartialOrd<RArc<T>> for RArc<T> where
    T: PartialOrd, 

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Pointer for RArc<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Serialize for RArc<T> where
    T: Serialize, 

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<T> StableAbi for RArc<T> where
    T: __StableAbi, 

type IsNonZeroType = False

Whether this type has a single invalid bit-pattern.

const LAYOUT: &'static TypeLayout

The layout of the type provided by implementors.

const ABI_CONSTS: AbiConsts

const-equivalents of the associated types.

impl<T> Eq for RArc<T> where
    T: Eq, 

impl<T> Send for RArc<T> where
    T: Send + Sync, 

impl<T> Sync for RArc<T> where
    T: Send + Sync,