Struct std::sync::mpsc::Receiver
[−]
[src]
pub struct Receiver<T> { // some fields omitted }
The receiving-half of Rust's channel type. This half can only be owned by one thread
Methods
impl<T> Receiver<T>
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.
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. Once a message is
sent to the corresponding Sender
, 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
fn main() { 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()); }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:
fn main() { 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()); }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());
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.