[−][src]Module tokio_sync::mpsc
A multi-producer, single-consumer queue for sending values across asynchronous tasks.
Similar to std
, channel creation provides Receiver
and Sender
handles. Receiver
implements Stream
and allows a task to read values
out of the channel. If there is no message to read, the current task will be
notified when a new value is sent. Sender
implements the Sink
trait
and allows sending messages into the channel. If the channel is at capacity,
the send is rejected and the task will be notified when additional capacity
is available. In other words, the channel provides backpressure.
Unbounded channels are also available using the unbounded_channel
constructor.
Disconnection
When all Sender
handles have been dropped, it is no longer
possible to send values into the channel. This is considered the termination
event of the stream. As such, Receiver::poll
returns Ok(Ready(None))
.
If the Receiver
handle is dropped, then messages can no longer
be read out of the channel. In this case, all further attempts to send will
result in an error.
Clean Shutdown
When the Receiver
is dropped, it is possible for unprocessed messages to
remain in the channel. Instead, it is usually desirable to perform a "clean"
shutdown. To do this, the receiver first calls close
, which will prevent
any further messages to be sent into the channel. Then, the receiver
consumes the channel to completion, at which point the receiver can be
dropped.
Modules
error | Channel error types |
Structs
Receiver | Receive values from the associated |
Sender | Send values to the associated |
UnboundedReceiver | Receive values from the associated |
UnboundedSender | Send values to the associated |
Functions
channel | Create a bounded mpsc channel for communicating between asynchronous tasks, returning the sender/receiver halves. |
unbounded_channel | Create an unbounded mpsc channel for communicating between asynchronous tasks. |