Concurrent Fixed-Size Allocation and Free in Constant Time

TL;DR

This paper introduces a concurrent memory allocation algorithm that supports fixed-size allocate and free operations in constant time, using minimal synchronization primitives, suitable for asynchronous multi-process systems.

Contribution

It presents the first implementation of fixed-size allocate and free operations that are both constant time and practical in concurrent environments.

Findings

Supports allocation and free in O(1) worst-case time

Uses only single-word read, write, and CAS operations

Achieves Θ(p^2) space overhead for p processes

Abstract

Our goal is to efficiently solve the dynamic memory allocation problem in a concurrent setting where processes run asynchronously. On $p$ processes, we can support allocation and free for fixed-sized blocks with $O(1)$ worst-case time per operation, $\Theta(p^2)$ additive space overhead, and using only single-word read, write, and CAS. While many algorithms rely on having constant-time fixed-size allocate and free, we present the first implementation of these two operations that is constant time with reasonable space overhead.