A Scalable, Portable, and Memory-Efficient Lock-Free FIFO Queue

Official repository: https://github.com/rusnikola/lfqueue

Publications

wCQ: A Fast Wait-Free Queue with Bounded Memory Usage.
In Proceedings of the 34th ACM Symposium on Parallelism in Algorithms
and Architectures (SPAA'22). Philadelphia, PA, USA.

Paper

A Scalable, Portable, and Memory-Efficient Lock-Free FIFO Queue.
In Proceedings of the 33rd International Symposium on DIStributed
Computing (DISC'19). Budapest, Hungary.

Paper

Source code license

Copyright (c) 2019, 2021 Ruslan Nikolaev. All Rights Reserved.

The SCQ/SCQD/SCQ2/NCQ/wCQ code is dual-licensed under 2-Clause BSD and MIT.

Description

The benchmark code is in the "benchmark" directory,
which is forked from the original WFQUEUE's benchmark
available [here](https://github.com/chaoran/fast-wait-free-queue).
For usage, see its original README file in "benchmark".

Additional queues were implemented. See the description below for
details.

Both GCC and LLVM should be supported. Older versions may lack
support for lfring\_cas2.h and wfring\_cas2.h and/or have
suboptimal performance. We have tested the code with
GCC 8.3.0+ and LLVM 7.0.1+.

CAS

An implementation of the FAA test using CAS emulation (based on
the original FAA test).

NCQ

A naive implementation of the ring buffer. The implementation is in
lfring\_naive.h.

SCQ

This is a "bare-bones" SCQ which simply implements *enqueue* and *dequeue*
(all platforms). The implementation is in lfring\_cas1.h.

SCQD

This is a version which stores pointers as data entries through indirection
(all platforms). The implementation is in lfring\_cas1.h.

SCQ2

This is a version which stores pointers through double-width CAS
(certain platforms such as x86-64). The implementation is in lfring\_cas2.h.

wCQ

An implementation of a wait-free version of SCQ, which uses double-width
CAS (certain platforms such as x86-64). The implementation is in
wfring\_cas2.h.

wcq 0.1.0

A Scalable, Portable, and Memory-Efficient Lock-Free FIFO Queue