Struct RwArc

pub struct RwArc<T>(Arc<Inner<T>>);

A reference-counting pointer with read-write capabilities.

This is essentially Arc<RwLock<T>>, so it can provide read-write capabilities through RwArc::read and RwArc::write.

In addition, this allows to derive another reference-counting pointer with read-only capabilities (RoArc) via RwArc::clone_ro.

The purpose of having this type is to allow lockless (read) access to the underlying data when there is only one RwArc instance for the particular allocation (note that there can be any number of RoArc instances for that allocation). See the RwArc::get method for more details.

Tuple Fields

0: Arc<Inner<T>>

Implementations

impl<T> RwArc<T>

pub fn new(data: T) -> Self

Creates a new RwArc<T>.

pub fn read(&self) -> RwLockReadGuard<'_, T, PreemptDisabled>

Acquires the read lock for immutable access.

pub fn write(&self) -> RwLockWriteGuard<'_, T, PreemptDisabled>

Acquires the write lock for mutable access.

pub fn get(&mut self) -> Option<&T>

Returns an immutable reference if no other RwArc points to the same allocation.

This method is cheap because it does not acquire a lock.

It’s still sound because:

• The mutable reference to self and the condition ensure that we are exclusively accessing the unique RwArc instance for the particular allocation.
• There may be any number of RoArcs pointing to the same allocation, but they may only produce immutable references to the underlying data.

pub fn clone_ro(&self) -> RoArc<T>

Clones a RoArc that points to the same allocation.

impl<T: Clone> RwArc<T>

pub fn get_cloned(&self) -> T

Returns the contained value by cloning it.

Trait Implementations

impl<T> Clone for RwArc<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> Drop for RwArc<T>

fn drop(&mut self)

Executes the destructor for this type.