[Paper Review] Design and Implementation of Dynamic Memory Management in a Reversible Object-Oriented Programming Language

Martin Holm Cservenka|arXiv (Cornell University)|Apr 12, 2018

Cloud Computing and Resource Management3 citations

TL;DR

This paper presents Roopl++, an extension of the reversible object-oriented language Roopl, enabling dynamic memory management via a Buddy Memory layout to support non-trivial reversible data structures like doubly linked lists and binary trees. The approach ensures garbage-free computation through reversible assembly translations in Pisa, demonstrating that complex, expressive data structures are feasible within the reversible computing paradigm without violating reversibility principles.

ABSTRACT

The reversible object-oriented programming language (ROOPL) was presented in late 2016 and proved that object-oriented programming paradigms works in the reversible setting. The language featured simple statically scoped objects which made non-trivial programs tedious, if not impossible to write using the limited tools provided. We introduce an extension to ROOPL in form the new language ROOPL++, featuring dynamic memory management and fixed-sized arrays for increased language expressiveness. The language is a superset of ROOPL and has formally been defined by its language semantics, type system and computational universality. Considerations for reversible memory manager layouts are discussed and ultimately lead to the selection of the Buddy Memory layout. Translations of the extensions added in ROOPL++ to the reversible assembly language PISA are presented to provide garbage-free computations. The dynamic memory management extension successfully increases the expressiveness of ROOPL and as a result, shows that non-trivial reversible data structures, such as binary trees and doubly-linked lists, are feasible and do not contradict the reversible computing paradigm.

Motivation & Objective

• To extend the reversible object-oriented language Roopl with dynamic memory management and fixed-sized arrays to increase expressiveness.
• To design a reversible memory management system that supports complex data structures without generating garbage.
• To formally define Roopl++'s semantics, type system, and computational universality.
• To translate Roopl++ constructs into the reversible assembly language Pisa for garbage-free execution.
• To demonstrate that non-trivial reversible data structures—such as doubly linked lists and binary trees—are feasible within the reversible computing model.

Proposed method

• Adopted the Buddy Memory layout for reversible memory allocation, ensuring deterministic and invertible memory management.
• Extended Roopl with array support, object instantiation, and local blocks to increase language expressiveness.
• Defined a formal type system and operational semantics for Roopl++ using environment-store judgments and reversible store transformations.
• Introduced a new expression rule for array element access that preserves reversibility and does not alter the store.
• Translated Roopl++ programs into the reversible assembly language Pisa, enabling backward execution and garbage-free computation.
• Validated the approach by implementing and verifying reversible versions of doubly linked lists and binary trees.

Experimental results

Research questions

• RQ1 Can dynamic memory management be integrated into a reversible object-oriented language without violating reversibility?
• RQ2 What memory layout strategy enables reversible allocation and deallocation while minimizing fragmentation and garbage?
• RQ3 Can complex data structures like doubly linked lists and binary trees be implemented in a reversible language with full computational universality?
• RQ4 How can reversible semantics be preserved during array access and object manipulation in a reversible language?
• RQ5 Is it possible to translate high-level reversible programs into reversible assembly code that supports full backward execution?

Key findings

• The Buddy Memory layout was selected as the optimal memory management strategy due to its deterministic, invertible allocation and deallocation patterns.
• Roopl++ successfully supports the implementation of non-trivial reversible data structures, including doubly linked lists and binary trees, with full reversibility.
• The translation of Roopl++ into the Pisa reversible assembly language enables garbage-free computation and full backward execution.
• The language extension preserves injective (one-to-one) transformations, ensuring that all operations are locally invertible and no information is lost.
• The formal semantics and type system of Roopl++ ensure type safety and computational universality within the reversible computing framework.
• The work demonstrates that dynamic memory management is compatible with reversible computing, challenging the assumption that only static or simple data structures can be reversible.