Struct tokio::sync::mpsc::Receiver

pub struct Receiver<T> { /* fields omitted */ }

Receive values from the associated Sender.

Instances are created by the channel function.

Methods

impl<T> Receiver<T>

pub async fn recv<'_>(&'_ mut self) -> Option<T>

Receives the next value for this receiver.

None is returned when all Sender halves have dropped, indicating that no further values can be sent on the channel.

Examples

use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (mut tx, mut rx) = mpsc::channel(100);

    tokio::spawn(async move {
        tx.send("hello").await.unwrap();
    });

    assert_eq!(Some("hello"), rx.recv().await);
    assert_eq!(None, rx.recv().await);
}

Values are buffered:

use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (mut tx, mut rx) = mpsc::channel(100);

    tx.send("hello").await.unwrap();
    tx.send("world").await.unwrap();

    assert_eq!(Some("hello"), rx.recv().await);
    assert_eq!(Some("world"), rx.recv().await);
}

pub fn try_recv(&mut self) -> Result<T, TryRecvError>

Attempts to return a pending value on this receiver without blocking.

This method will never block the caller in order to wait for data to become available. Instead, this will always return immediately with a possible option of pending data on the channel.

This is useful for a flavor of "optimistic check" before deciding to block on a receiver.

Compared with recv, this function has two failure cases instead of one (one for disconnection, one for an empty buffer).

pub fn close(&mut self)

Closes the receiving half of a channel, without dropping it.

This prevents any further messages from being sent on the channel while still enabling the receiver to drain messages that are buffered.

Trait Implementations

impl<T> Debug for Receiver<T>

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

Formats the value using the given formatter.

impl<T> Unpin for Receiver<T>