Spec-Zone.ru › Tokio

Struct OwnedRwLockReadGuard 

pub struct OwnedRwLockReadGuard<T: ?Sized, U: ?Sized = T> { /* private fields */ }
Available on crate feature sync only.

Owned RAII structure used to release the shared read access of a lock when dropped.

This structure is created by the read_owned method on RwLock.

Implementations

impl<T: ?Sized, U: ?Sized> OwnedRwLockReadGuard<T, U>

pub fn map<F, V: ?Sized>(this: Self, f: F) -> OwnedRwLockReadGuard<T, V>
where F: FnOnce(&U) -> &V,

Makes a new OwnedRwLockReadGuard for a component of the locked data. This operation cannot fail as the OwnedRwLockReadGuard passed in already locked the data.

This is an associated function that needs to be used as OwnedRwLockReadGuard::map(...). A method would interfere with methods of the same name on the contents of the locked data.

Examples
use std::sync::Arc;
use tokio::sync::{RwLock, OwnedRwLockReadGuard};

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);

let lock = Arc::new(RwLock::new(Foo(1)));

let guard = lock.read_owned().await;
let guard = OwnedRwLockReadGuard::map(guard, |f| &f.0);

assert_eq!(1, *guard);

pub fn try_map<F, V: ?Sized>( this: Self, f: F, ) -> Result<OwnedRwLockReadGuard<T, V>, Self>
where F: FnOnce(&U) -> Option<&V>,

Attempts to make a new OwnedRwLockReadGuard for a component of the locked data. The original guard is returned if the closure returns None.

This operation cannot fail as the OwnedRwLockReadGuard passed in already locked the data.

This is an associated function that needs to be used as OwnedRwLockReadGuard::try_map(..). A method would interfere with methods of the same name on the contents of the locked data.

Examples
use std::sync::Arc;
use tokio::sync::{RwLock, OwnedRwLockReadGuard};

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);

let lock = Arc::new(RwLock::new(Foo(1)));

let guard = lock.read_owned().await;
let guard = OwnedRwLockReadGuard::try_map(guard, |f| Some(&f.0)).expect("should not fail");

assert_eq!(1, *guard);

pub fn rwlock(this: &Self) -> &Arc<RwLock<T>> ⓘ

Returns a reference to the original Arc<RwLock>.

Examples
use std::sync::Arc;
use tokio::sync::{RwLock, OwnedRwLockReadGuard};

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);

let lock = Arc::new(RwLock::new(Foo(1)));

let guard = lock.clone().read_owned().await;
assert!(Arc::ptr_eq(&lock, OwnedRwLockReadGuard::rwlock(&guard)));

let guard = OwnedRwLockReadGuard::map(guard, |f| &f.0);
assert!(Arc::ptr_eq(&lock, OwnedRwLockReadGuard::rwlock(&guard)));

Trait Implementations

impl<T: ?Sized, U> Debug for OwnedRwLockReadGuard<T, U>
where U: Debug + ?Sized,

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

Formats the value using the given formatter. Read more

impl<T: ?Sized, U: ?Sized> Deref for OwnedRwLockReadGuard<T, U>

type Target = U

The resulting type after dereferencing.

fn deref(&self) -> &U

Dereferences the value.

impl<T: ?Sized, U> Display for OwnedRwLockReadGuard<T, U>
where U: Display + ?Sized,

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

Formats the value using the given formatter. Read more

impl<T: ?Sized, U: ?Sized> Drop for OwnedRwLockReadGuard<T, U>

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

impl<T, U> Send for OwnedRwLockReadGuard<T, U>
where T: ?Sized + Send + Sync, U: ?Sized + Sync,

impl<T, U> Sync for OwnedRwLockReadGuard<T, U>
where T: ?Sized + Send + Sync, U: ?Sized + Send + Sync,

Auto Trait Implementations

impl<T, U = T> !RefUnwindSafe for OwnedRwLockReadGuard<T, U>

impl<T, U = T> !UnwindSafe for OwnedRwLockReadGuard<T, U>

impl<T, U> Freeze for OwnedRwLockReadGuard<T, U>
where T: ?Sized, U: ?Sized,

impl<T, U> Unpin for OwnedRwLockReadGuard<T, U>
where T: Unpin + ?Sized, U: ?Sized,

impl<T, U> UnsafeUnpin for OwnedRwLockReadGuard<T, U>
where T: ?Sized, U: ?Sized,

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> Instrument for T

fn instrument(self, span: Span) -> Instrumented<Self> ⓘ

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

fn in_current_span(self) -> Instrumented<Self> ⓘ

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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<P, T> Receiver for P
where P: Deref<Target = T> + ?Sized, T: ?Sized,

type Target = T

🔬This is a nightly-only experimental API. (arbitrary_self_types)
The target type on which the method may be called.

impl<T> ToString for T
where T: Display + ?Sized,

fn to_string(&self) -> String

Converts the given value to a String. 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<T> WithSubscriber for T

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> ⓘ
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

fn with_current_subscriber(self) -> WithDispatch<Self> ⓘ

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more

MIT License
Copyright © Tokio Contributors
https://docs.rs/tokio/1.53.1/tokio/sync/struct.OwnedRwLockReadGuard.html

Spec-Zone.ru

Настройки Оффлайн Что нового Помощь О нас
Spec-Zone .ru
спецификации, руководства, описания, API