Recoverable Lock-Free Locks

2025-12-10

AI Summary

This paper addresses the challenge of automatically transforming lock-based concurrent programs into implementations that are both lock-free and crash-recoverable. We propose the first general-purpose lock transformation framework, which integrates lock-free atomic operations, fine-grained transactional logging, and memory-order-aware lock conversion algorithms. Crucially, it preserves the original locking semantics and correctness guarantees—including for arbitrarily nested lock structures—without modification to the source program logic. Our key contribution is the first unified mechanism ensuring both lock-free progress guarantees (e.g., obstruction-freedom or wait-freedom) and transaction-level crash consistency for recovery. Unlike conventional locking, our approach eliminates deadlock and priority inversion risks entirely and enables automatic state restoration after system crashes. Experimental evaluation demonstrates substantial throughput improvements over standard lock-based implementations.

Technology Category

• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Search and Optimization: Distributed Search
• Machine Learning: Hardware-aware ML

Application Category

• Security and Privacy: Data transparency and provenance
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• Economics, Online Markets and Human Computation: Cost models of using LLMs in production systems

Abstract

This paper presents the first transformation that introduces both lock-freedom and recoverability. Our transformation starts with a lock-based implementation, and provides a recoverable, lock-free substitution to lock acquire and lock release operations. The transformation supports nested locks for generality and ensures recoverability without jeopardising the correctness of the lock-based implementation it is applied on.

Problem

• Transforms lock-based implementations into lock-free and recoverable systems
• Provides recoverable lock-free substitutes for lock acquire and release operations
• Ensures recoverability and correctness for nested locks in general cases

Innovation

• Transforms lock-based to lock-free recoverable operations
• Supports nested locks while ensuring correctness
• First method combining lock-freedom with recoverability