[urcu.git] / LICENSE

Userspace RCU library licensing
Mathieu Desnoyers
May 10, 2009


* LGPLv2.1

The library part is distributed under LGPLv2.1 or later. See lgpl-2.1.txt for
details. This applies to :

urcu.h
urcu.c
urcu-static.h
arch_x86.h
arch_ppc.h

LGPL-compatible source code can statically use the library header using :

#define _LGPL_SOURCE
#include <urcu.h>

Dynamic-only linking with the LGPL library is used if _LGPL_SOURCE is not
defined. It permits relinking with newer versions of the library, which is
required by the LGPL license.


* MIT-style license :

xchg() privimitive has been rewritten from scratch starting from atomic_ops 1.2
which has a MIT-style license that is intended to allow use in both free and
proprietary software:
	http://www.hpl.hp.com/research/linux/atomic_ops/LICENSING.txt
	http://www.hpl.hp.com/personal/Hans_Boehm/gc/gc_source/

This license applies to :

arch_atomic_x86.h
arch_atomic_ppc.h


* GPLv2

Library test code is distributed under the GPLv2 license. See gpl-2.0.txt for
details. This applies to :

urcutorture.h
urcutorture.c
api_x86.h
api_ppc.h
test_urcu.c
test_urcu_yield.c
test_rwlock_timing.c
urcu-asm.c


Various details :

ACCESS_ONCE(), likely(), unlikely() and barrier() are considered trivial enough
that copyright does not apply to them. I (Mathieu Desnoyers) re-typed them from
scratch in a mail client just to prove it.
Commit	Line	Data
af02d47e MD	1	Userspace RCU library licensing
	2	Mathieu Desnoyers
	3	May 10, 2009
	4
0114ba7f MD	5
	6	* LGPLv2.1
	7
af02d47e MD	8	The library part is distributed under LGPLv2.1 or later. See lgpl-2.1.txt for
	9	details. This applies to :
	10
	11	urcu.h
	12	urcu.c
	13	urcu-static.h
	14	arch_x86.h
	15	arch_ppc.h
	16
	17	LGPL-compatible source code can statically use the library header using :
	18
	19	#define _LGPL_SOURCE
	20	#include <urcu.h>
	21
	22	Dynamic-only linking with the LGPL library is used if _LGPL_SOURCE is not
	23	defined. It permits relinking with newer versions of the library, which is
	24	required by the LGPL license.
	25
0114ba7f MD	26
	27	* MIT-style license :
	28
	29	xchg() privimitive has been rewritten from scratch starting from atomic_ops 1.2
	30	which has a MIT-style license that is intended to allow use in both free and
	31	proprietary software:
	32	http://www.hpl.hp.com/research/linux/atomic_ops/LICENSING.txt
	33	http://www.hpl.hp.com/personal/Hans_Boehm/gc/gc_source/
	34
	35	This license applies to :
	36
	37	arch_atomic_x86.h
	38	arch_atomic_ppc.h
	39
	40
	41	* GPLv2
	42
af02d47e MD	43	Library test code is distributed under the GPLv2 license. See gpl-2.0.txt for
	44	details. This applies to :
	45
	46	urcutorture.h
	47	urcutorture.c
	48	api_x86.h
	49	api_ppc.h
	50	test_urcu.c
	51	test_urcu_yield.c
	52	test_rwlock_timing.c
5e13fab8	53	urcu-asm.c
0114ba7f MD	54
	55
	56	Various details :
	57
	58	ACCESS_ONCE(), likely(), unlikely() and barrier() are considered trivial enough
	59	that copyright does not apply to them. I (Mathieu Desnoyers) re-typed them from
	60	scratch in a mail client just to prove it.