Struct SharedReadLock

pub struct SharedReadLock<T: ?Sized>(/* private fields */);

A read-only reference to a resource possibly shared with up to one Shared and many WeakReadLocks.

Implementations

impl<T: ?Sized> SharedReadLock<T>

pub async fn lock(&self) -> SharedReadGuard<'_, T>

Lock this SharedReadLock, causing the current task to yield until the lock has been acquired.

pub fn try_lock(&self) -> TryLockResult<SharedReadGuard<'_, T>>

Try to lock this SharedReadLock.

If the value is currently locked for writing through the corresponding Shared instance, returns TryLockError.

pub async fn lock_owned(self) -> OwnedSharedReadGuard<T>

Lock this SharedReadLock, causing the current task to yield until the lock has been acquired.

This method is identical to lock, except that the returned guard keeps a clone of the internal Arc instead of borrowing it. Therefore, the guard does has a 'static lifetime.

pub fn downgrade(&self) -> WeakReadLock<T>

Create a new WeakReadLock pointer to this allocation.

pub fn try_upgrade(self) -> Result<Shared<T>, Self>

Upgrade a SharedReadLock to Shared.

This only return Ok(_) if there are no other references (including a Shared, or weak references) to the inner value, since otherwise it would be possible to have multiple Shareds for the same inner value alive at the same time, which would violate Shareds invariant of being the only reference that is able to mutate the inner value.

pub fn from_inner(rwlock: Arc<RwLock<T>>) -> Self

Create a SharedReadLock from its internal representation, Arc<RwLock<T>>.

You can use this to create a SharedReadLock from a shared RwLock without ever using Shared, if you want to expose an API where there is a value that can be written only from inside one module or crate, but outside users should be allowed to obtain a reusable lock for reading the inner value.

pub fn try_into_inner(self) -> Result<Arc<RwLock<T>>, Self>

Attempt to turn this SharedReadLock into its internal representation, Arc<RwLock<T>>.

This returns Ok(_) only if there are no further references (including a Shared, or weak references) to the inner value, since otherwise it would be possible to have a Shared and an Arc<RwLock<T>> for the same inner value alive at the same time, which would violate Shareds invariant of being the only reference that is able to mutate the inner value.

Trait Implementations

impl<T: ?Sized> Clone for SharedReadLock<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 + ?Sized> Debug for SharedReadLock<T>

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

Formats the value using the given formatter.