pub struct Permit<'a, T> { /* private fields */ }
Expand description
Permits to send one value into the channel.
Permit
values are returned by Sender::reserve()
and Sender::try_reserve()
and are used to guarantee channel capacity before generating a message to send.
Implementations
sourceimpl<T> Permit<'_, T>
impl<T> Permit<'_, T>
sourcepub fn send(self, value: T)
pub fn send(self, value: 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.
Examples
use tokio::sync::mpsc;
#[tokio::main]
async fn main() {
let (tx, mut rx) = mpsc::channel(1);
// Reserve capacity
let permit = tx.reserve().await.unwrap();
// Trying to send directly on the `tx` will fail due to no
// available capacity.
assert!(tx.try_send(123).is_err());
// Send a message on the permit
permit.send(456);
// The value sent on the permit is received
assert_eq!(rx.recv().await.unwrap(), 456);
}
Trait Implementations
Auto Trait Implementations
impl<'a, T> !RefUnwindSafe for Permit<'a, T>
impl<'a, T> Send for Permit<'a, T> where
T: Send,
impl<'a, T> Sync for Permit<'a, T> where
T: Send,
impl<'a, T> Unpin for Permit<'a, T>
impl<'a, T> !UnwindSafe for Permit<'a, T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more