Struct tokio::sync::mpsc::OwnedPermit

source ·
pub struct OwnedPermit<T> { /* private fields */ }
Expand description

Owned permit to send one value into the channel.

This is identical to the Permit type, except that it moves the sender rather than borrowing it.

OwnedPermit values are returned by Sender::reserve_owned() and Sender::try_reserve_owned() and are used to guarantee channel capacity before generating a message to send.

Implementations§

source§

impl<T> OwnedPermit<T>

source

pub fn send(self, value: T) -> Sender<T>

Sends a value using the reserved capacity.

Capacity for the message has already been reserved. The message is sent to the receiver and the permit is consumed. The operation will succeed even if the receiver half has been closed. See Receiver::close for more details on performing a clean shutdown.

Unlike Permit::send, this method returns the Sender from which the OwnedPermit was reserved.

Examples
use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (tx, mut rx) = mpsc::channel(1);

    // Reserve capacity
    let permit = tx.reserve_owned().await.unwrap();

    // Send a message on the permit, returning the sender.
    let tx = permit.send(456);

    // The value sent on the permit is received
    assert_eq!(rx.recv().await.unwrap(), 456);

    // We may now reuse `tx` to send another message.
    tx.send(789).await.unwrap();
}
source

pub fn release(self) -> Sender<T>

Releases the reserved capacity without sending a message, returning the Sender.

Examples
use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (tx, rx) = mpsc::channel(1);

    // Clone the sender and reserve capacity
    let permit = tx.clone().reserve_owned().await.unwrap();

    // Trying to send on the original `tx` will fail, since the `permit`
    // has reserved all the available capacity.
    assert!(tx.try_send(123).is_err());

    // Release the permit without sending a message, returning the clone
    // of the sender.
    let tx2 = permit.release();

    // We may now reuse `tx` to send another message.
    tx.send(789).await.unwrap();
}

Trait Implementations§

source§

impl<T> Debug for OwnedPermit<T>

source§

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

Formats the value using the given formatter. Read more
source§

impl<T> Drop for OwnedPermit<T>

source§

fn drop(&mut self)

Executes the destructor for this type. Read more

Auto Trait Implementations§

§

impl<T> !RefUnwindSafe for OwnedPermit<T>

§

impl<T> Send for OwnedPermit<T>where T: Send,

§

impl<T> Sync for OwnedPermit<T>where T: Send,

§

impl<T> Unpin for OwnedPermit<T>

§

impl<T> !UnwindSafe for OwnedPermit<T>

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

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

source§

fn into(self) -> U

Calls U::from(self).

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

source§

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

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
source§

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

§

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

The type returned in the event of a conversion error.
source§

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

Performs the conversion.