Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/ivmai/libatomic_ops

The atomic_ops project (Atomic memory update operations portable implementation)
https://github.com/ivmai/libatomic_ops

Last synced: 3 days ago
JSON representation

The atomic_ops project (Atomic memory update operations portable implementation)

Awesome Lists containing this project

README 

        
# The atomic_ops library (`libatomic_ops`)



IN NEW CODE, PLEASE USE C11 OR C++14 STANDARD ATOMICS INSTEAD OF THE CORE

LIBRARY IN THIS PACKAGE.



[![Travis-CI build status](https://app.travis-ci.com/ivmai/libatomic_ops.svg?branch=master)](https://app.travis-ci.com/github/ivmai/libatomic_ops)

[![AppVeyor CI build status](https://ci.appveyor.com/api/projects/status/github/ivmai/libatomic_ops?branch=master&svg=true)](https://ci.appveyor.com/project/ivmai/libatomic-ops)

[![GitHub Actions build status](https://github.com/ivmai/libatomic_ops/actions/workflows/cmake-build.yml/badge.svg?event=push)](https://github.com/ivmai/libatomic_ops/actions?query=branch%3Amaster)

[![Codecov.io](https://codecov.io/github/ivmai/libatomic_ops/coverage.svg?branch=master)](https://codecov.io/github/ivmai/libatomic_ops?branch=master)

[![Coveralls test coverage status](https://coveralls.io/repos/ivmai/libatomic_ops/badge.png?branch=master)](https://coveralls.io/github/ivmai/libatomic_ops)

[![Coverity Scan build status](https://scan.coverity.com/projects/10809/badge.svg)](https://scan.coverity.com/projects/ivmai-libatomic_ops)

[![FOSSA Status](https://app.fossa.com/api/projects/git%2Bgithub.com%2Fivmai%2Flibatomic_ops.svg?type=shield)](https://app.fossa.com/projects/git%2Bgithub.com%2Fivmai%2Flibatomic_ops?ref=badge_shield)

[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/6333/badge)](https://bestpractices.coreinfrastructure.org/projects/6333)

[![Hits-of-Code](https://hitsofcode.com/github/ivmai/libatomic_ops?branch=master)](https://hitsofcode.com/github/ivmai/libatomic_ops/view)

[![GitHub code size in bytes](https://img.shields.io/github/languages/code-size/ivmai/libatomic_ops)](https://shields.io/category/size)

[![Github All Releases](https://img.shields.io/github/downloads/ivmai/libatomic_ops/total.svg)](https://shields.io/category/downloads)

[![Packaging status](https://repology.org/badge/tiny-repos/libatomic-ops.svg)](https://repology.org/project/libatomic-ops/versions)



This is version 7.9.0 (next release development) of libatomic_ops.



License: [MIT](LICENSE) for core library / [GPL-2.0](COPYING) for gpl

extension.



## Download



You might find a more recent/stable version on the

[Download](https://github.com/ivmai/libatomic_ops/wiki/Download) page, or

[BDWGC site](http://www.hboehm.info/gc/).



Also, the latest bug fixes and new features are available in the

[development repository](https://github.com/ivmai/libatomic_ops).



## Overview



This package provides semi-portable access to hardware-provided

atomic memory update operations on a number of architectures.  These might

allow you to write code:



* That does more interesting things in signal handlers.



* Makes more effective use of multiprocessors by allowing you to write

  clever lock-free code.  Note that such code is very difficult to get

  right, and will unavoidably be less portable than lock-based code.  It

  is also not always faster than lock-based code.  But it may occasionally

  be a large performance win.



* To experiment with new and much better thread programming paradigms, etc.



Please see other README files for the details:



* [README_details.txt](README_details.txt) - details about atomic_ops.h



* [README_malloc.txt](README_malloc.txt) - a simple almost-lock-free malloc

  implementation (part of libatomic_ops_gpl)



* [README_stack.txt](README_stack.txt) -  an almost lock-free LIFO linked

  lists (stack) implementation (part of libatomic_ops_gpl)



## Installation and Usage



The configuration and build scripts for this package were generated by

Automake/Autoconf.  `./configure; make; sudo make install` in this

directory should work.  For a more customized build, see the output of

`./configure --help`.  To build it from the development repository,

`./autogen.sh` should be executed first.



Alternatively, CMake could be use to build this package, e.g.

`cmake . && cmake --build .` in this directory should work.



Note that much of the content of this library is in the header files.

However, two small libraries are built and installed:



* `libatomic_ops.a` is a support (core) library, which is not needed on some

  platforms. This is intended to be usable, under some mild restrictions,

  in free or proprietary code, as are all the header files.

  See [LICENSE](LICENSE) for more details about the licensing.



* `libatomic_ops_gpl.a` is a so called gpl extension library containing some

  higher level facilities.  This code is covered by the GPL.  The contents

  correspond to the headers `atomic_ops_malloc.h` and `atomic_ops_stack.h`.

  Not built and not installed if `--disable-gpl` option is passed to

  `configure` (or if `-Denable_gpl=OFF` option is passed to `cmake` if the

  latter is used to build the package).  The licensing details are given in

  [COPYING](COPYING) and [LICENSE](LICENSE) files.



## Platform Specific Notes



Win32/64: src/Makefile.msft contains a very simple Makefile for building

and running tests and building the gpl library.  The core `libatomic_ops`

implementation is entirely in header files (libatomic_ops.lib is built anyway

to match that of the configure-based build process, but libatomic_ops.lib has

only the implementation of the internal AO_pause() used by the gpl library).

More information is provided in [README_win32.txt](README_win32.txt) file.



HP-UX/PA-RISC: `aCC -Ae` won't work as a C compiler, since it doesn't support

inline assembly code.  Use cc.



## Feedback, Contribution, Questions and Notifications



Please address bug reports and new feature ideas to

[GitHub issues](https://github.com/ivmai/libatomic_ops/issues).  Before the

submission please check that it has not been done yet by someone else.



If you want to contribute, submit

a [pull request](https://github.com/ivmai/libatomic_ops/pulls) to GitHub.



If you need help, use

[Stack Overflow](https://stackoverflow.com/questions/tagged/atomic-ops).

Older questions on the site can be found by

[this query](https://stackoverflow.com/search?q=atomic_ops).

Older technical discussions are also available in `bdwgc` mailing list

archive - it can be downloaded as a

[compressed file](https://github.com/ivmai/bdwgc/files/1038163/bdwgc-mailing-list-archive-2017_04.tar.gz)

or browsed at [Narkive](http://bdwgc.opendylan.narkive.com) (please search

for _atomic_ keyword).



To get new release announcements, subscribe to

[RSS feed](https://github.com/ivmai/libatomic_ops/releases.atom).

(To receive the notifications by email, a 3rd-party free service like

[IFTTT RSS Feed](https://ifttt.com/feed) can be setup.)

To be notified on all issues, please

[watch](https://github.com/ivmai/libatomic_ops/watchers) the project on

GitHub.



## Copyright & Warranty, Contributors



Please be aware of the dual nature of the license of libatomic_ops:



* the core part (implementing semi-portable access to hardware-provided

  atomic memory operations) is released under MIT license



* the gpl extension (almost lock-free malloc and stack implementations) and

  the tests are released under GPL-2.0 license



The exact licensing information is provided in [LICENSE](LICENSE) file.



The library contributors are listed in [AUTHORS](AUTHORS) file.