Remote Direct Memory Access (RDMA) is a memory technology that allows remote devices to directly write to and read from each other's memory, bypassing components such as the CPU and operating system. This enables low-latency high-throughput networking, as required for many modern data centres, HPC applications and AI/ML workloads. However, baseline RDMA comprises a highly permissive weak memory model that is difficult to use in practice and has only recently been formalised. In this paper, we introduce the Library of Composable Objects (LOCO), a formally verified library for building multi-node objects on RDMA, filling the gap between shared memory and distributed system programming. LOCO objects are well-encapsulated and take advantage of the strong locality and the weak consistency characteristics of RDMA. They have performance comparable to custom RDMA systems (e.g. distributed maps), but with a far simpler programming model amenable to formal proofs of correctness. To support verification, we develop a novel modular declarative verification framework, called Mowgli, that is flexible enough to model multinode objects and is independent of a memory consistency model. We instantiate Mowgli with the RDMA memory model, and use it to verify correctness of LOCO libraries.
@article{arxiv.2510.10531,
title = {A Verified High-Performance Composable Object Library for Remote Direct Memory Access (Extended Version)},
author = {Guillaume Ambal and George Hodgkins and Mark Madler and Gregory Chockler and Brijesh Dongol and Joseph Izraelevitz and Azalea Raad and Viktor Vafeiadis},
journal= {arXiv preprint arXiv:2510.10531},
year = {2025}
}