Struct Sender

pub struct Sender<T> { /* private fields */ }

The sending side of a channel.

Examples

use std::thread;
use crossbeam_channel::unbounded;

let (s1, r) = unbounded();
let s2 = s1.clone();

thread::spawn(move || s1.send(1).unwrap());
thread::spawn(move || s2.send(2).unwrap());

let msg1 = r.recv().unwrap();
let msg2 = r.recv().unwrap();

assert_eq!(msg1 + msg2, 3);

Implementations

impl<T> Sender<T>

pub fn try_send(&self, msg: T) -> Result<(), TrySendError<T>>

Attempts to send a message into the channel without blocking.

This method will either send a message into the channel immediately or return an error if the channel is full or disconnected. The returned error contains the original message.

If called on a zero-capacity channel, this method will send the message only if there happens to be a receive operation on the other side of the channel at the same time.

Examples

use crossbeam_channel::{bounded, TrySendError};

let (s, r) = bounded(1);

assert_eq!(s.try_send(1), Ok(()));
assert_eq!(s.try_send(2), Err(TrySendError::Full(2)));

drop(r);
assert_eq!(s.try_send(3), Err(TrySendError::Disconnected(3)));

pub fn send(&self, msg: T) -> Result<(), SendError<T>>

Blocks the current thread until a message is sent or the channel is disconnected.

If the channel is full and not disconnected, this call will block until the send operation can proceed. If the channel becomes disconnected, this call will wake up and return an error. The returned error contains the original message.

If called on a zero-capacity channel, this method will wait for a receive operation to appear on the other side of the channel.

Examples

use std::thread;
use std::time::Duration;
use crossbeam_channel::{bounded, SendError};

let (s, r) = bounded(1);
assert_eq!(s.send(1), Ok(()));

thread::spawn(move || {
    assert_eq!(r.recv(), Ok(1));
    thread::sleep(Duration::from_secs(1));
    drop(r);
});

assert_eq!(s.send(2), Ok(()));
assert_eq!(s.send(3), Err(SendError(3)));

pub fn send_timeout( &self, msg: T, timeout: Duration, ) -> Result<(), SendTimeoutError<T>>

Waits for a message to be sent into the channel, but only for a limited time.

If the channel is full and not disconnected, this call will block until the send operation can proceed or the operation times out. If the channel becomes disconnected, this call will wake up and return an error. The returned error contains the original message.

If called on a zero-capacity channel, this method will wait for a receive operation to appear on the other side of the channel.

Examples

use std::thread;
use std::time::Duration;
use crossbeam_channel::{bounded, SendTimeoutError};

let (s, r) = bounded(0);

thread::spawn(move || {
    thread::sleep(Duration::from_secs(1));
    assert_eq!(r.recv(), Ok(2));
    drop(r);
});

assert_eq!(
    s.send_timeout(1, Duration::from_millis(500)),
    Err(SendTimeoutError::Timeout(1)),
);
assert_eq!(
    s.send_timeout(2, Duration::from_secs(1)),
    Ok(()),
);
assert_eq!(
    s.send_timeout(3, Duration::from_millis(500)),
    Err(SendTimeoutError::Disconnected(3)),
);

pub fn send_deadline( &self, msg: T, deadline: Instant, ) -> Result<(), SendTimeoutError<T>>

Waits for a message to be sent into the channel, but only until a given deadline.

If the channel is full and not disconnected, this call will block until the send operation can proceed or the operation times out. If the channel becomes disconnected, this call will wake up and return an error. The returned error contains the original message.

If called on a zero-capacity channel, this method will wait for a receive operation to appear on the other side of the channel.

Examples

use std::thread;
use std::time::{Duration, Instant};
use crossbeam_channel::{bounded, SendTimeoutError};

let (s, r) = bounded(0);

thread::spawn(move || {
    thread::sleep(Duration::from_secs(1));
    assert_eq!(r.recv(), Ok(2));
    drop(r);
});

let now = Instant::now();

assert_eq!(
    s.send_deadline(1, now + Duration::from_millis(500)),
    Err(SendTimeoutError::Timeout(1)),
);
assert_eq!(
    s.send_deadline(2, now + Duration::from_millis(1500)),
    Ok(()),
);
assert_eq!(
    s.send_deadline(3, now + Duration::from_millis(2000)),
    Err(SendTimeoutError::Disconnected(3)),
);

pub fn is_empty(&self) -> bool

Returns true if the channel is empty.

Note: Zero-capacity channels are always empty.

Examples

use crossbeam_channel::unbounded;

let (s, r) = unbounded();
assert!(s.is_empty());

s.send(0).unwrap();
assert!(!s.is_empty());

pub fn is_full(&self) -> bool

Returns true if the channel is full.

Note: Zero-capacity channels are always full.

Examples

use crossbeam_channel::bounded;

let (s, r) = bounded(1);

assert!(!s.is_full());
s.send(0).unwrap();
assert!(s.is_full());

pub fn len(&self) -> usize

Returns the number of messages in the channel.

Examples

use crossbeam_channel::unbounded;

let (s, r) = unbounded();
assert_eq!(s.len(), 0);

s.send(1).unwrap();
s.send(2).unwrap();
assert_eq!(s.len(), 2);

pub fn capacity(&self) -> Option<usize>

If the channel is bounded, returns its capacity.

Examples

use crossbeam_channel::{bounded, unbounded};

let (s, _) = unbounded::<i32>();
assert_eq!(s.capacity(), None);

let (s, _) = bounded::<i32>(5);
assert_eq!(s.capacity(), Some(5));

let (s, _) = bounded::<i32>(0);
assert_eq!(s.capacity(), Some(0));

pub fn same_channel(&self, other: &Sender<T>) -> bool

Returns true if senders belong to the same channel.

Examples

use crossbeam_channel::unbounded;

let (s, _) = unbounded::<usize>();

let s2 = s.clone();
assert!(s.same_channel(&s2));

let (s3, _) = unbounded();
assert!(!s.same_channel(&s3));

Trait Implementations

impl<T> Clone for Sender<T>

fn clone(&self) -> Sender<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Sender<T>

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

Formats the value using the given formatter.

impl<T> Drop for Sender<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> RefUnwindSafe for Sender<T>

impl<T> Send for Sender<T>

where T: Send,

impl<T> Sync for Sender<T>

where T: Send,

impl<T> UnwindSafe for Sender<T>