MPI bindings for Rust

The Message Passing Interface (MPI) is a specification for a message-passing style concurrency library. Implementations of MPI are often used to structure parallel computation on High Performance Computing systems. The MPI specification describes bindings for the C programming language (and through it C++) as well as for the Fortran programming language. This library tries to bridge the gap into a more rustic world.

Requirements

An implementation of the C language interface of MPI-3.0. These bindings are currently tested with:

• OpenMPI 1.8.8, 1.10.0
• MPICH 3.1.4, 3.0.4

To generate FFI definitions rsmpi uses rust-bindgen which needs libclang. See the bindgen project page for troubleshooting.

Building

cargo build

Usage

Add the mpi crate as a dependency in your Cargo.toml:

[dependencies]
mpi = "0.1.10"

Then use it in your program like this:

extern crate mpi;

use mpi::traits::*;

fn main() {
    let universe = mpi::initialize().unwrap();
    let world = universe.world();
    let size = world.size();
    let rank = world.rank();

    if size != 2 {
        panic!("Size of MPI_COMM_WORLD must be 2, but is {}!", size);
     }

    match rank {
        0 => {
            let msg = vec![4.0f64, 8.0, 15.0];
            world.process_at_rank(rank + 1).send(&msg[..]);
        }
        1 => {
            let (msg, status) = world.receive_vec::<f64>();
            println!("Process {} got message {:?}.\nStatus is: {:?}", rank, msg, status);
        }
        _ => unreachable!()
    }
}

Features

The bindings follow the MPI 3.1 specification.

Currently supported:

• Groups, Contexts, Communicators:
  • Group and (Intra-)Communicator management from section 6 is mostly complete.
  • no Inter-Communicators
  • noprocess topologies
• Point to point communication:
  • standard, buffered, synchronous and ready mode send in blocking and non-blocking variants
  • receive in blocking and non-blocking variants
  • send-receive
  • probe
  • matched probe/receive
• Collective communication:
  • barrier in blocking and non-blocking variants
  • broadcast
  • (all) gather
  • scatter
  • all to all
  • no varying counts operations
  • no reductions/scans
• Datatypes: Bridging between Rust types and MPI basic types as well as custom MPI datatypes which can act as views into buffers.

Not supported (yet):

• Process management
• One-sided communication (RMA)
• MPI parallel I/O
• A million small things

Documentation

cargo doc

Or see the hosted documentation.

Examples

See files in examples/.

License

The MIT license, see the file LICENSE.