Flat combined Red Black Trees

TL;DR

This paper explores how to adapt the flat combining concurrency technique to red-black trees, which are traditionally difficult to batch due to their balancing properties, aiming to improve concurrent operation efficiency.

Contribution

It investigates alternative methods to enable flat combining for red-black trees, addressing the challenge of batching operations in a balanced binary search tree.

Findings

Identifies challenges in batching red-black tree operations

Proposes potential alternative approaches for flat combining

Provides analysis of batching feasibility for red-black trees

Abstract

Flat combining is a concurrency threaded technique whereby one thread performs all the operations in batch by scanning a queue of operations to-be-done and performing them together. Flat combining makes sense as long as k operations each taking O(n) separately can be batched together and done in less than O(k*n). Red black tree is a balanced binary search tree with permanent balancing warranties. Operations in red black tree are hard to batch together: for example inserting nodes in two different branches of the tree affect different areas of the tree. In this paper we investigate alternatives to making a flat combine approach work for red black trees.