# Tracking in Order to Recover: Detectable Recovery of Lock-Free Data Structures

## TL;DR

This paper introduces a tracking method for creating detectably recoverable lock-free data structures suitable for non-volatile memory systems, ensuring crash recovery without extensive logging.

## Contribution

The paper proposes Info-Structure Based (ISB) tracking, a novel technique that enhances lock-free data structures with minimal overhead for detectable recovery.

## Key findings

- Successfully applied to queue, linked list, binary search tree, and exchanger
- Reduces recovery overhead compared to full logging methods
- Demonstrates feasibility through experimental evaluation

## Abstract

This paper presents the tracking approach for deriving detectably recoverable (and thus also durable) implementations of many widely-used concurrent data structures. Such data structures, satisfying detectable recovery, are appealing for emerging systems featuring byte-addressable non-volatile main memory (NVRAM), whose persistence allows to efficiently resurrect failed processes after crashes. Detectable recovery ensures that after a crash, every executed operation is able to recover and return a correct response, and that the state of the data structure is not corrupted. Info-Structure Based (ISB)-tracking amends descriptor objects used in existing lock-free helping schemes with additional fields that track an operation's progress towards completion and persists these fields to memory in order to ensure detectable recovery. ISB-tracking avoids full-fledged logging and tracks the progress of concurrent operations in a per-process manner, thus reducing the cost of ensuring detectable recovery. We have applied ISB-tracking to derive detectably recoverable implementations of a queue, a linked list, a binary search tree, and an exchanger. Experimental results show the feasibility of the technique.