timely_communication 0.1.0

A simple communication infrastructure providing typed exchange channels.

This crate is part of the timely dataflow system, used primarily for its inter-worker communication. It may be indepedently useful, but it is separated out mostly to make clear boundaries in the project.

Threads are spawned with an allocator::Generic, whose allocate method returns a pair of several send endpoints and one receive endpoint. Messages sent into a send endpoint will eventually be received by the corresponding worker, if it receives often enough. The point-to-point channels are each FIFO, but with no fairness guarantees.

To be communicated, a type must implement the Serialize trait. A default implementation of Serialize is provided for any type implementing Abomonation. To implement other serialization strategies, wrap your type and implement Serialize for your wrapper.

Channel endpoints also implement a lower-level push and pull interface (through the Push and Pull traits), which is used for more precise control of resources.

#Examples

// configure for two threads, just one process.
let config = communication::Configuration::Process(2);

// initailizes communication, spawns workers
communication::initialize(config, |mut allocator| {
    println!("worker {} started", allocator.index());

    // allocates pair of senders list and one receiver.
    let (mut senders, mut receiver) = allocator.allocate();

    // send typed data along each channel
    senders[0].send(format!("hello, {}", 0));
    senders[1].send(format!("hello, {}", 1));

    // no support for termination notification,
    // we have to count down ourselves.
    let mut expecting = 2;
    while expecting > 0 {
        if let Some(message) = receiver.recv() {
            println!("worker {}: received: <{}>", allocator.index(), message);
            expecting -= 1;
        }
    }
});

The should produce output like:

worker 0 started
worker 1 started
worker 0: received: <hello, 0>
worker 1: received: <hello, 1>
worker 0: received: <hello, 0>
worker 1: received: <hello, 1>