Expand description

The feature-rich, portable async channel library.

Why use Postage?

  • Includes a rich set of channels.
    • barrier, a oneshot channel that transmits when the sender half is dropped.
    • broadcast, a lossless multi-producer, multi-consumer broadcast channel with backpressure (no lagging!).
    • dispatch, a multi-producer, multi-consumer queue.
    • mpsc, a multi-producer, single-consumer channel.
    • oneshot, a oneshot transfer channel.
    • watch, a state distribution channel with a value that can be borrowed.
  • Works with any executor.
    • Currently regressions are written for tokio and async-std.
    • With the futures-traits feature, channels implement the futures Sink/Stream traits.
  • Throughly tested.
    • Channels have full unit test coverage, and integration test coverage with multiple async executors.
  • Comes with built-in Sink and Stream combinators.
    • Sinks can be chained, and filtered.
    • Streams can be chained, filtered, mapped, and merged.
    • With the logging feature, Sinks and streams can log their values. This is really helpful when debugging applications.

See the readme for benchmarks.

Cargo features:


Barriers transmit when the sender half is dropped, and can synchronize events in async tasks.

Provides a lossless, MPMC channel. All receivers are guaranteed to recieve each message.

A fixed-capacity multi-producer, multi-consumer queue. At most one receiver will observe each value.

A fixed-capacity multi-producer, single-consumer channel.

Oneshot channels transmit a single value between a sender and a reciever.

Imports the Sink and Stream traits.

A sink for values which are asynchronously accepted, until the target is closed.

A stream of values which are asynchronously produced, until the source is closed.

A state distribution channel. The internal state can be borrowed or cloned, but receivers do not observe every value.


The Context of an asynchronous task.