Struct uchan::RawReceiver

pub struct RawReceiver<E, T> { /* private fields */ }

The receiving half of Rust’s raw_channel type. This half can only be owned by one thread.

Messages sent to the channel can be retrieved using recv.

Examples

use uchan::channel;
use std::thread;
use std::time::Duration;

let (send, recv) = channel();

thread::spawn(move || {
    send.send("Hello world!").unwrap();
    thread::sleep(Duration::from_secs(2)); // block for two seconds
    send.send("Delayed for 2 seconds").unwrap();
});

println!("{}", recv.recv().unwrap()); // Received immediately
println!("Waiting...");
println!("{}", recv.recv().unwrap()); // Received after 2 seconds

Implementations

impl<E, T> RawReceiver<E, T>

pub fn try_recv(&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).

Examples

use uchan::{Receiver, channel};

let (_, receiver): (_, Receiver<i32>) = channel();

assert!(receiver.try_recv().is_err());

impl<E: Event, T> RawReceiver<E, T>

pub fn recv(&self) -> Result<T, RecvError>

Attempts to wait for a value on this receiver, returning an error if the corresponding channel has hung up.

This function will always block the current thread if there is no data available and it’s possible for more data to be sent (at least one sender still exists). Once a message is sent to the corresponding RawSender, this receiver will wake up and return that message.

If the corresponding RawSender has disconnected, or it disconnects while this call is blocking, this call will wake up and return Err to indicate that no more messages can ever be received on this channel. However, since channels are buffered, messages sent before the disconnect will still be properly received.

Examples

use uchan::channel;
use std::thread;

let (send, recv) = channel();
let handle = thread::spawn(move || {
    send.send(1u8).unwrap();
});

handle.join().unwrap();

assert_eq!(Ok(1), recv.recv());

Buffering behavior:

use uchan::{channel, RecvError};
use std::thread;

let (send, recv) = channel();
let handle = thread::spawn(move || {
    send.send(1u8).unwrap();
    send.send(2).unwrap();
    send.send(3).unwrap();
    drop(send);
});

// wait for the thread to join so we ensure the sender is dropped
handle.join().unwrap();

assert_eq!(Ok(1), recv.recv());
assert_eq!(Ok(2), recv.recv());
assert_eq!(Ok(3), recv.recv());
assert_eq!(Err(RecvError), recv.recv());

impl<E: TimedEvent, T> RawReceiver<E, T>

pub fn recv_timeout(&self, timeout: E::Duration) -> Result<T, RecvTimeoutError>

Attempts to wait for a value on this receiver, returning an error if the corresponding channel has hung up, or if it waits more than timeout.

This function will always block the current thread if there is no data available and it’s possible for more data to be sent (at least one sender still exists). Once a message is sent to the corresponding RawSender this receiver will wake up and return that message.

If the corresponding RawSender has disconnected, or it disconnects while this call is blocking, this call will wake up and return Err to indicate that no more messages can ever be received on this channel. However, since channels are buffered, messages sent before the disconnect will still be properly received.

Examples

Successfully receiving value before encountering timeout:

use std::thread;
use std::time::Duration;
use uchan::channel;

let (send, recv) = channel();

thread::spawn(move || {
    send.send('a').unwrap();
});

assert_eq!(
    recv.recv_timeout(Duration::from_millis(400)),
    Ok('a')
);

Receiving an error upon reaching timeout:

use std::thread;
use std::time::Duration;
use uchan::{channel, RecvTimeoutError};

let (send, recv) = channel();

thread::spawn(move || {
    thread::sleep(Duration::from_millis(800));
    send.send('a').unwrap();
});

assert_eq!(
    recv.recv_timeout(Duration::from_millis(400)),
    Err(RecvTimeoutError::Timeout)
);

Trait Implementations

impl<E, T> Debug for RawReceiver<E, T>

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

Formats the value using the given formatter.

impl<E, T> Drop for RawReceiver<E, T>

fn drop(&mut self)

Executes the destructor for this type.