SPLASH 2016
Sun 30 October - Fri 4 November 2016 Amsterdam, Netherlands
Wed 2 Nov 2016 11:45 - 12:10 at Matterhorn 2 - Semantics and Verification Chair(s): Jonathan Aldrich

Recent advances in networking hardware have led to a new generation of Remote Memory Access (RMA) networks in which processors from different machines can communicate directly, bypassing the operating system and allowing higher performance. Researchers and practitioners have proposed libraries and programming models for RMA to enable the development of applications running on these networks,

However, the memory models implied by these RMA libraries and languages are often loosely specified, poorly understood, and differ depending on the underlying network architecture and other factors. Hence, it is difficult to precisely reason about the semantics of RMA programs or how changes in the network architecture affect them.

We address this problem with the following contributions: (i) a \emph{coreRMA} language which serves as a common foundation, formalizing the essential characteristics of RMA programming; (ii) complete axiomatic semantics for that language;
(iii) integration of our semantics with an existing constraint solver, enabling us to exhaustively generate \emph{coreRMA} programs (litmus tests) up to a specified bound and check whether the tests satisfy their specification; and (iv) extensive validation of our semantics on real-world RMA systems.
We generated and ran $7441$ litmus tests using each of the low-level RMA network APIs: DMAPP, VPI Verbs, and Portals 4. Our results confirmed that our model successfully captures behaviors exhibited by these networks. Moreover, we found RMA programs that behave inconsistently with existing documentation, confirmed by network experts.

Our work provides an important step towards understanding existing RMA networks, thus influencing the design of future RMA interfaces and hardware.

#### Wed 2 Nov

 10:30 - 12:10: OOPSLA - Semantics and Verification at Matterhorn 2 Chair(s): Jonathan Aldrich 10:30 - 10:55Talk Semantics-Based Program Verifiers for All Languages DOI Media Attached 10:55 - 11:20Talk Hoare-Style Specifications as Correctness Conditions for Non-linearizable Concurrent Objects DOI Pre-print Media Attached File Attached 11:20 - 11:45Talk An Operational Semantics for C/C++11 Concurrency DOI 11:45 - 12:10Talk Modeling and Analysis of Remote Memory Access Programming DOI Pre-print Media Attached