Struct scale_info::prelude::sync::mpsc::Receiver

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

The receiving half of Rust’s channel (or sync_channel) type. This half can only be owned by one thread.

Messages sent to the channel can be retrieved using recv.

§Examples

use std::sync::mpsc::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§

source§

impl<T> Receiver<T>

1.0.0 · source

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 std::sync::mpsc::{Receiver, channel};

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

assert!(receiver.try_recv().is_err());
1.0.0 · source

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 Sender (or SyncSender), this receiver will wake up and return that message.

If the corresponding Sender 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 std::sync::mpsc;
use std::thread;

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

handle.join().unwrap();

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

Buffering behavior:

use std::sync::mpsc;
use std::thread;
use std::sync::mpsc::RecvError;

let (send, recv) = mpsc::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());
1.12.0 · source

pub fn recv_timeout(&self, timeout: 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 Sender (or SyncSender), this receiver will wake up and return that message.

If the corresponding Sender 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 std::sync::mpsc;

let (send, recv) = mpsc::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 std::sync::mpsc;

let (send, recv) = mpsc::channel();

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

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

pub fn recv_deadline(&self, deadline: Instant) -> Result<T, RecvTimeoutError>

🔬This is a nightly-only experimental API. (deadline_api)

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

This function will always block the current thread if there is no data available and it’s possible for more data to be sent. Once a message is sent to the corresponding Sender (or SyncSender), then this receiver will wake up and return that message.

If the corresponding Sender 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 reaching deadline:

#![feature(deadline_api)]
use std::thread;
use std::time::{Duration, Instant};
use std::sync::mpsc;

let (send, recv) = mpsc::channel();

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

assert_eq!(
    recv.recv_deadline(Instant::now() + Duration::from_millis(400)),
    Ok('a')
);

Receiving an error upon reaching deadline:

#![feature(deadline_api)]
use std::thread;
use std::time::{Duration, Instant};
use std::sync::mpsc;

let (send, recv) = mpsc::channel();

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

assert_eq!(
    recv.recv_deadline(Instant::now() + Duration::from_millis(400)),
    Err(mpsc::RecvTimeoutError::Timeout)
);
1.0.0 · source

pub fn iter(&self) -> Iter<'_, T>

Returns an iterator that will block waiting for messages, but never panic!. It will return None when the channel has hung up.

§Examples
use std::sync::mpsc::channel;
use std::thread;

let (send, recv) = channel();

thread::spawn(move || {
    send.send(1).unwrap();
    send.send(2).unwrap();
    send.send(3).unwrap();
});

let mut iter = recv.iter();
assert_eq!(iter.next(), Some(1));
assert_eq!(iter.next(), Some(2));
assert_eq!(iter.next(), Some(3));
assert_eq!(iter.next(), None);
1.15.0 · source

pub fn try_iter(&self) -> TryIter<'_, T>

Returns an iterator that will attempt to yield all pending values. It will return None if there are no more pending values or if the channel has hung up. The iterator will never panic! or block the user by waiting for values.

§Examples
use std::sync::mpsc::channel;
use std::thread;
use std::time::Duration;

let (sender, receiver) = channel();

// nothing is in the buffer yet
assert!(receiver.try_iter().next().is_none());

thread::spawn(move || {
    thread::sleep(Duration::from_secs(1));
    sender.send(1).unwrap();
    sender.send(2).unwrap();
    sender.send(3).unwrap();
});

// nothing is in the buffer yet
assert!(receiver.try_iter().next().is_none());

// block for two seconds
thread::sleep(Duration::from_secs(2));

let mut iter = receiver.try_iter();
assert_eq!(iter.next(), Some(1));
assert_eq!(iter.next(), Some(2));
assert_eq!(iter.next(), Some(3));
assert_eq!(iter.next(), None);

Trait Implementations§

1.8.0 · source§

impl<T> Debug for Receiver<T>

source§

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

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

impl<'a, T> IntoIterator for &'a Receiver<T>

§

type Item = T

The type of the elements being iterated over.
§

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?
source§

fn into_iter(self) -> Iter<'a, T>

Creates an iterator from a value. Read more
1.1.0 · source§

impl<T> IntoIterator for Receiver<T>

§

type Item = T

The type of the elements being iterated over.
§

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?
source§

fn into_iter(self) -> IntoIter<T>

Creates an iterator from a value. Read more
1.0.0 · source§

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

1.0.0 · source§

impl<T> !Sync for Receiver<T>

Auto Trait Implementations§

§

impl<T> Freeze for Receiver<T>

§

impl<T> RefUnwindSafe for Receiver<T>

§

impl<T> Unpin for Receiver<T>

§

impl<T> UnwindSafe for Receiver<T>

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> Conv for T

source§

fn conv<T>(self) -> T
where Self: Into<T>,

Converts self into T using Into<T>. Read more
source§

impl<T> FmtForward for T

source§

fn fmt_binary(self) -> FmtBinary<Self>
where Self: Binary,

Causes self to use its Binary implementation when Debug-formatted.
source§

fn fmt_display(self) -> FmtDisplay<Self>
where Self: Display,

Causes self to use its Display implementation when Debug-formatted.
source§

fn fmt_lower_exp(self) -> FmtLowerExp<Self>
where Self: LowerExp,

Causes self to use its LowerExp implementation when Debug-formatted.
source§

fn fmt_lower_hex(self) -> FmtLowerHex<Self>
where Self: LowerHex,

Causes self to use its LowerHex implementation when Debug-formatted.
source§

fn fmt_octal(self) -> FmtOctal<Self>
where Self: Octal,

Causes self to use its Octal implementation when Debug-formatted.
source§

fn fmt_pointer(self) -> FmtPointer<Self>
where Self: Pointer,

Causes self to use its Pointer implementation when Debug-formatted.
source§

fn fmt_upper_exp(self) -> FmtUpperExp<Self>
where Self: UpperExp,

Causes self to use its UpperExp implementation when Debug-formatted.
source§

fn fmt_upper_hex(self) -> FmtUpperHex<Self>
where Self: UpperHex,

Causes self to use its UpperHex implementation when Debug-formatted.
source§

fn fmt_list(self) -> FmtList<Self>
where &'a Self: for<'a> IntoIterator,

Formats each item in a sequence. 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 T
where 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> Pipe for T
where T: ?Sized,

source§

fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> R
where Self: Sized,

Pipes by value. This is generally the method you want to use. Read more
source§

fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> R
where R: 'a,

Borrows self and passes that borrow into the pipe function. Read more
source§

fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R
where R: 'a,

Mutably borrows self and passes that borrow into the pipe function. Read more
source§

fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R
where Self: Borrow<B>, B: 'a + ?Sized, R: 'a,

Borrows self, then passes self.borrow() into the pipe function. Read more
source§

fn pipe_borrow_mut<'a, B, R>( &'a mut self, func: impl FnOnce(&'a mut B) -> R, ) -> R
where Self: BorrowMut<B>, B: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.borrow_mut() into the pipe function. Read more
source§

fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R
where Self: AsRef<U>, U: 'a + ?Sized, R: 'a,

Borrows self, then passes self.as_ref() into the pipe function.
source§

fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R
where Self: AsMut<U>, U: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.as_mut() into the pipe function.
source§

fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R
where Self: Deref<Target = T>, T: 'a + ?Sized, R: 'a,

Borrows self, then passes self.deref() into the pipe function.
source§

fn pipe_deref_mut<'a, T, R>( &'a mut self, func: impl FnOnce(&'a mut T) -> R, ) -> R
where Self: DerefMut<Target = T> + Deref, T: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.deref_mut() into the pipe function.
source§

impl<T> Tap for T

source§

fn tap(self, func: impl FnOnce(&Self)) -> Self

Immutable access to a value. Read more
source§

fn tap_mut(self, func: impl FnOnce(&mut Self)) -> Self

Mutable access to a value. Read more
source§

fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Immutable access to the Borrow<B> of a value. Read more
source§

fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Mutable access to the BorrowMut<B> of a value. Read more
source§

fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Immutable access to the AsRef<R> view of a value. Read more
source§

fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Mutable access to the AsMut<R> view of a value. Read more
source§

fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Immutable access to the Deref::Target of a value. Read more
source§

fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Mutable access to the Deref::Target of a value. Read more
source§

fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self

Calls .tap() only in debug builds, and is erased in release builds.
source§

fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self

Calls .tap_mut() only in debug builds, and is erased in release builds.
source§

fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Calls .tap_borrow() only in debug builds, and is erased in release builds.
source§

fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Calls .tap_borrow_mut() only in debug builds, and is erased in release builds.
source§

fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Calls .tap_ref() only in debug builds, and is erased in release builds.
source§

fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Calls .tap_ref_mut() only in debug builds, and is erased in release builds.
source§

fn tap_deref_dbg<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Calls .tap_deref() only in debug builds, and is erased in release builds.
source§

fn tap_deref_mut_dbg<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Calls .tap_deref_mut() only in debug builds, and is erased in release builds.
source§

impl<T> TryConv for T

source§

fn try_conv<T>(self) -> Result<T, Self::Error>
where Self: TryInto<T>,

Attempts to convert self into T using TryInto<T>. Read more
source§

impl<T, U> TryFrom<U> for T
where 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 T
where 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.
source§

impl<T> JsonSchemaMaybe for T