Implement an atomic refcounter with a weak but correct (1) memory order,
and expose a simple API.
(1) See for example "Using weakly ordered C++ atomics correctly" by Hans
Boehm at CppCon 2016 (the refcounting part also applies to C11):
<https://www.youtube.com/watch?v=M15UKpNlpeM&t=45m15s>
Signed-off-by: Steve Lhomme <robux4@ycbcr.xyz>
This fixes mismatched binary interface when either:
- the versions of C and C++ were different within the LibVLC build, or
- an out-of-tree plugin used a different language versin than LibVLC.
The LibVLC implementation for ISO C atomics with Intel intrinsics was
not generally binary compatible with the native implementation of the
compiler. In other words, only one atomics implementation can be used
in one LibVLC installation. The One Definition Rule from C++ imposes
that native implementation is used, so the LibVLC implementation is
hereby removed.
Regression from edf1c76018.
This change is required since some atomic operations of the
Interlocked API are only available for desktop apps.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
This way, the official atomic functions will be used when available,
rather than VLC's own implementation.
This commit also enables proper atomic operations on some platforms
or with some toolchains. __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 is not
defined on some platforms such as ARM Linux, nor by other compilers
than GCC such as LLVM/clang. Then atomic operations wrongly fell
back to the lame mutex-based implementation.
This will break support for some old compilers and old or irrelevant
instruction set architectures. They would need to provide replacement
for the Intel-originated __sync_* builtin functions.
Since this constitutes mostly of macros and type definitions, it would
not fit too well in compat/. Most of the code would end up in
<vlc_fixups.h> rather than compat/. Moreover, I doubt that those
functions would be detected properly with AC_CHECK_FUNCS or
AC_REPLACE_FUNCS.
Anyway, VLC already has a separate header, and it will need to keep it
until <stdatomic.h> can be relied upon... many years from now.
Re-license almost all of libVLC and libVLCcore to LGPLv2.1+
This move was authorized by the developers, either:
- by e-mail,
- by vote at the VideoLAN Dev Days 2011,
- on the license website,
- in a contract, oral or written.
No objection was raised, so far.
The developers agreeing are:
Justus Piater
Alexis Ballier
Alexander Bethke
Mohammed Adnène Trojette
Alex Converse
Alexey Sokolov
Alexis de Lattre
Andre Pang
Anthony Loiseau
Cyril Deguet
André Weber
Boris Dorès
Brieuc Jeunhomme
Benjamin Drung
Hugo Beauzée-Luyssen
Benoit Steiner
Benjamin Pracht
Bernie Purcell
Przemyslaw Fiala
Arnaud de Bossoreille de Ribou
Brad Smith
Nick Briggs
Christopher Rath
Christophe Courtaut
Christopher Mueller
Clement Chesnin
Andres Krapf
Damien Fouilleul
David Flynn
Sebastien Zwickert
Antoine Cellerier
Jérôme Decoodt
Jérome Decoodt
Dylan Yudaken
Eduard Babayan
Eugenio Jarosiewicz
Elliot Murphy
Eric Petit
Erwan Tulou
Etienne Membrives
Ludovic Fauvet
Fabio Ritrovato
Tobias Güntner
Jakub Wieczorek
Frédéric Crozat
Francois Cartegnie
Laurent Aimar
Florian G. Pflug
Felix Paul Kühne
Frank Enderle
Rafaël Carré
Simon Latapie
Gildas Bazin
Geoffroy Couprie
Julien / Gellule
Gildas Bazin
Arnaud Schauly
Toralf Niebuhr
Vicente Jimenez Aguilar
Derk-Jan Hartman
Henri Fallon
Ilkka Ollakka
Olivier Teulière
Rémi Duraffort
Jakob Leben
Jean-Baptiste Kempf
Jean-Paul Saman
Jean-Philippe Grimaldi
Jean-François Massol
Gaël Hendryckx
Jakob Leben
Jean-Marc Dressler
Jai Menon
Johan Bilien
Johann Ransay
Joris van Rooij
JP Dinger
Jean-Philippe André
Adrien Grand
Juha Jeronen
Juho Vähä-Herttua
Kaarlo Raiha
Kaarlo Raiha
Kamil Baldyga
Keary Griffin
Ken Self
KO Myung-Hun
Pierre Ynard
Filippo Carone
Loïc Minier
Luca Barbato
Lucas C. Villa Real
Lukas Durfina
Adrien Maglo
Marc Ariberti
Mark Lee
Mark Moriarty
Martin Storsjö
Christophe Massiot
Michel Kaempf
Marian Ďurkovič
Mirsal Ennaime
Carlo Calabrò
Damien Lucas
Naohiro Koriyama
Basos G
Pierre Baillet
Vincent Penquerc'h
Olivier Aubert
Pankaj Yadav
Paul Corke
Pierre d'Herbemont
Philippe Morin
Antoine Lejeune
Michael Ploujnikov
Jean-Marc Dressler
Michael Hanselmann
Rafaël Carré
Ramiro Polla
Rémi Denis-Courmont
Renaud Dartus
Richard Shepherd
Faustino Osuna
Arnaud Vallat
Rob Jonson
Robert Jedrzejczyk
Steve Lhomme
Rocky Bernstein
Romain Goyet
Rov Juvano
Sam Hocevar
Martin T. H. Sandsmark
Sebastian Birk
Sébastien Escudier
Vincent Seguin
Fabio Ritrovato
Sigmund Augdal Helberg
Casian Andrei
Srikanth Raju
Hannes Domani
Stéphane Borel
Stephan Krempel
Stephan Assmus
Tony Castley
Pavlov Konstantin
Eric Petit
Tanguy Krotoff
Dennis van Amerongen
Michel Lespinasse
Can Wu
Xavier Marchesini
Sébastien Toque
Christophe Mutricy
Yoann Peronneau
Yohann Martineau
Yuval Tze
Scott Caudle
Clément Stenac
It is possible, that some minor piece of code was badly tracked, for
some reasons (SVN, mainly) or that some small developers did not answer.
However, as an "œuvre collective", defined as in "CPI 113-2 alinéa 3",
and seeing "Cour. Cass. 17 Mai 1978", and seeing that the editor and
the very vast majority of developers have agreed (> 99.99% of the code,
> 99% of developers), we are fine here.
Hugo Beauzée-Luyssen