Generating Concurrent Programs From Sequential Data Structure Knowledge

TL;DR

This paper presents an automated approach to generate concurrent data structure operations from sequential specifications using Answer Set Programming, mimicking human reasoning to produce safe concurrent code.

Contribution

It introduces a novel method employing ASP for automated, reasoning-based transformation of sequential data structures into concurrent versions, a first in the field.

Findings

Successfully generates concurrent code for linked lists and binary search trees.

Uses ASP to model pointer data structures and synchronization.

Demonstrates systematic, sound reasoning comparable to human judgment.

Abstract

In this paper we tackle the problem of automatically designing concurrent data structure operations given a sequential data structure specification and knowledge about concurrent behavior. Designing concurrent code is a non-trivial task even in simplest of cases. Humans often design concurrent data structure operations by transforming sequential versions into their respective concurrent versions. This requires an understanding of the data structure, its sequential behavior, thread interactions during concurrent execution and shared memory synchronization primitives. We mechanize this design process using automated commonsense reasoning. We assume that the data structure description is provided as axioms alongside the sequential code of its algebraic operations. This information is used to automatically derive concurrent code for that data structure, such as dictionary operations for linked lists and binary search trees. Knowledge in our case is expressed using Answer Set Programming (ASP), and we employ deduction, induction and abduction---just as humans do---in the reasoning involved. ASP allows for succinct modeling of first order theories of pointer data structures, run-time thread interactions and shared memory synchronization. Our reasoner can systematically make the same judgments as a human reasoner while constructing provably safe concurrent code. We present several reasoning challenges involved in transforming the sequential data structure into its equivalent concurrent version. All the reasoning tasks are encoded in ASP and our reasoner can make sound judgments to transform sequential code into concurrent code. To the best of our knowledge, our work is the first one to use commonsense reasoning to automatically transform sequential programs into concurrent code.