pub struct Sender<T, R = DefaultRecycle> { /* private fields */ }
std
only.Expand description
Synchronously receives values from associated Sender
s.
Instances of this struct are created by the channel
and
with_recycle
functions.
Implementations
sourceimpl<T, R> Sender<T, R> where
R: Recycle<T>,
impl<T, R> Sender<T, R> where
R: Recycle<T>,
sourcepub fn send_ref(&self) -> Result<SendRef<'_, T>, Closed>
pub fn send_ref(&self) -> Result<SendRef<'_, T>, Closed>
Reserves a slot in the channel to mutate in place, blocking until there is a free slot to write to.
This is similar to the send
method, but, rather than taking a
message by value to write to the channel, this method reserves a
writable slot in the channel, and returns a SendRef
that allows
mutating the slot in place. If the Receiver
end of the channel
uses the Receiver::recv_ref
method for receiving from the channel,
this allows allocations for channel messages to be reused in place.
Errors
If the Receiver
end of the channel has been dropped, this
returns a Closed
error.
Examples
Sending formatted strings by writing them directly to channel slots, in place:
use thingbuf::mpsc::blocking;
use std::{fmt::Write, thread};
let (tx, rx) = blocking::channel::<String>(8);
// Spawn a thread that prints each message received from the channel:
thread::spawn(move || {
for _ in 0..10 {
let msg = rx.recv_ref().unwrap();
println!("{}", msg);
}
});
// Until the channel closes, write formatted messages to the channel.
let mut count = 1;
while let Ok(mut value) = tx.send_ref() {
// Writing to the `SendRef` will reuse the *existing* string
// allocation in place.
write!(value, "hello from message {}", count)
.expect("writing to a `String` should never fail");
count += 1;
}
sourcepub fn send(&self, val: T) -> Result<(), Closed<T>>
pub fn send(&self, val: T) -> Result<(), Closed<T>>
Sends a message by value, blocking until there is a free slot to write to.
This method takes the message by value, and replaces any previous
value in the slot. This means that the channel will not function
as an object pool while sending messages with send
. This method is
most appropriate when messages don’t own reusable heap allocations,
or when the Receiver
end of the channel must receive messages by
moving them out of the channel by value (using the
Receiver::recv
method). When messages in the channel own
reusable heap allocations (such as String
s or Vec
s), and the
Receiver
doesn’t need to receive them by value, consider using
send_ref
instead, to enable allocation reuse.
Errors
If the Receiver
end of the channel has been dropped, this
returns a Closed
error containing the sent value.
Examples
use thingbuf::mpsc::blocking;
use std::thread;
let (tx, rx) = blocking::channel(8);
// Spawn a thread that prints each message received from the channel:
thread::spawn(move || {
for _ in 0..10 {
let msg = rx.recv().unwrap();
println!("received message {}", msg);
}
});
// Until the channel closes, write the current iteration to the channel.
let mut count = 1;
while tx.send(count).is_ok() {
count += 1;
}
sourcepub fn try_send_ref(&self) -> Result<SendRef<'_, T>, TrySendError>
pub fn try_send_ref(&self) -> Result<SendRef<'_, T>, TrySendError>
Attempts to reserve a slot in the channel to mutate in place, without blocking until capacity is available.
This method differs from send_ref
by returning immediately if the
channel’s buffer is full or no Receiver
exists. Compared with
send_ref
, this method has two failure cases instead of one (one for
disconnection, one for a full buffer), and this method will never block.
Like send_ref
, this method returns a SendRef
that may be
used to mutate a slot in the channel’s buffer in place. Dropping the
SendRef
completes the send operation and makes the mutated value
available to the Receiver
.
Errors
If the channel capacity has been reached (i.e., the channel has n
buffered values where n
is the argument passed to
channel
/with_recycle
), then TrySendError::Full
is
returned. In this case, a future call to try_send
may succeed if
additional capacity becomes available.
If the receive half of the channel is closed (i.e., the Receiver
handle was dropped), the function returns TrySendError::Closed
.
Once the channel has closed, subsequent calls to try_send_ref
will
never succeed.
sourcepub fn try_send(&self, val: T) -> Result<(), TrySendError<T>>
pub fn try_send(&self, val: T) -> Result<(), TrySendError<T>>
Attempts to send a message by value immediately, without blocking until capacity is available.
This method differs from send
by returning immediately if the
channel’s buffer is full or no Receiver
exists. Compared with
send
, this method has two failure cases instead of one (one for
disconnection, one for a full buffer), and this method will never block.
Errors
If the channel capacity has been reached (i.e., the channel has n
buffered values where n
is the argument passed to
channel
/with_recycle
), then TrySendError::Full
is
returned. In this case, a future call to try_send
may succeed if
additional capacity becomes available.
If the receive half of the channel is closed (i.e., the Receiver
handle was dropped), the function returns TrySendError::Closed
.
Once the channel has closed, subsequent calls to try_send
will
never succeed.
In both cases, the error includes the value passed to try_send
.
Trait Implementations
Auto Trait Implementations
impl<T, R = DefaultRecycle> !RefUnwindSafe for Sender<T, R>
impl<T, R> Send for Sender<T, R> where
R: Send + Sync,
T: Send + Sync,
impl<T, R> Sync for Sender<T, R> where
R: Send + Sync,
T: Send + Sync,
impl<T, R> Unpin for Sender<T, R>
impl<T, R = DefaultRecycle> !UnwindSafe for Sender<T, R>
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
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcefn clone_into(&self, target: &mut T)
fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more