Crate mpi_rma 

Typed, safe MPI one-sided communication (RMA) for Rust, on top of rsmpi.

rsmpi does not expose RMA windows. This crate contains the raw RMA calls, extends every rsmpi communicator through CommunicatorRmaExt, and builds fixed-slot Ring transport on those windows.

Ring::safe provides backpressure with a cumulative-acknowledgement gate. Ring::raw never blocks and reports overwritten messages instead. Polling reads local memory; each safe Ring::ack call uses one atomic MPI operation.

use mpi::topology::Communicator;
use mpi_rma::Ring;

let world = universe.world();
// One lane from rank 0 to rank 1: 8 slots of 64 KiB each.
let ring = Ring::safe(&world, &[(0, 1, 8, 64 * 1024)]).unwrap();
if world.rank() == 0 {
    ring.send(1, b"hello").unwrap();
} else if world.rank() == 1 {
    'receive: loop {
        for message in ring.poll().unwrap() {
            ring.ack(message.origin, message.sequence).unwrap();
            break 'receive;
        }
        std::thread::yield_now();
    }
}
ring.close().unwrap();

See design.md for the slot layout, sequencing rules, and the acknowledge-gating model behind the ring transport, and BENCHMARKS.md for measured throughput and latency against MPI point-to-point.

Modules

traits

rsmpi-style trait prelude. Importing this extends the original communicator types in place; no communicator wrapper is involved.

Structs

Message

One message observed in a ring.

Ring

Sparse directed message rings packed into collective RMA windows.

Window

MPI-allocated homogeneous memory exposed to the communicator.

Enums

Error

MemoryModel

Traits

CommunicatorRmaExt

Method-style RMA extension for every rsmpi communicator.

RmaElement

Plain scalar values whose in-memory representation is safe for RMA.