[urcu.git] / urcu-pointer.h

#ifndef _URCU_POINTER_H
#define _URCU_POINTER_H

/*
 * urcu-pointer.h
 *
 * Userspace RCU header. Operations on pointers.
 *
 * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
 * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * IBM's contributions to this file may be relicensed under LGPLv2 or later.
 */

#include <urcu/compiler.h>
#include <urcu/arch.h>
#include <urcu/arch_uatomic.h>

#ifdef _LGPL_SOURCE

#include <urcu-pointer-static.h>

/*
 * rcu_dereference(ptr)
 *
 * Fetch a RCU-protected pointer. Typically used to copy the variable ptr to a
 * local variable.
 */
#define rcu_dereference		_rcu_dereference

/*
 * rcu_cmpxchg_pointer(type **ptr, type *new, type *old)
 * type *rcu_xchg_pointer(type **ptr, type *new)
 * type *rcu_set_pointer(type **ptr, type *new)
 *
 * RCU pointer updates.
 * @ptr: address of the pointer to modify
 * @new: new pointer value
 * @old: old pointer value (expected)
 *
 * return: old pointer value
 */
#define rcu_cmpxchg_pointer	_rcu_cmpxchg_pointer
#define rcu_xchg_pointer	_rcu_xchg_pointer
#define rcu_set_pointer		_rcu_set_pointer

/*
 * type *rcu_publish_content(type **ptr, type *new)
 *
 * Exchanges the pointer and waits for quiescent state. The pointer returned
 * can be freed. You are encouraged to use either
 * - rcu_cmpxchg_pointer
 * - rcu_xchg_pointer
 * - rcu_set_pointer
 * with call_rcu(free, ptr) instead to deal with reclamation more efficiently.
 */
#define rcu_publish_content	_rcu_publish_content

#else /* !_LGPL_SOURCE */

extern void *rcu_dereference(void *p);

extern void *rcu_cmpxchg_pointer_sym(void **p, void *old, void *_new);
#define rcu_cmpxchg_pointer(p, old, _new)		\
	rcu_cmpxchg_pointer_sym((void **)(p), (old), (_new))

extern void *rcu_xchg_pointer_sym(void **p, void *v);
#define rcu_xchg_pointer(p, v)				\
	rcu_xchg_pointer_sym((void **)(p), (v))

extern void *rcu_set_pointer_sym(void **p, void *v);
#define rcu_set_pointer(p, v)				\
	rcu_set_pointer_sym((void **)(p), (v))

extern void *rcu_publish_content_sym(void **p, void *v);
#define rcu_publish_content(p, v)			\
	rcu_publish_content_sym((void **)(p), (v))

extern void *rcu_assign_pointer_sym(void **p, void *v);

#endif /* !_LGPL_SOURCE */

/*
 * rcu_assign_pointer(type *ptr, type *new)
 *
 * Same as rcu_set_pointer, but takes the pointer to assign to rather than its
 * address as first parameter. Provided for compatibility with the Linux kernel
 * RCU semantic.
 */
#define rcu_assign_pointer(p, v)	rcu_set_pointer((&p), (v))

#endif /* _URCU_POINTER_H */
Commit	Line	Data
	1	#ifndef _URCU_POINTER_H
	2	#define _URCU_POINTER_H
	3
	4	/*
	5	* urcu-pointer.h
	6	*
	7	* Userspace RCU header. Operations on pointers.
	8	*
	9	* Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
	10	* Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
	11	*
	12	* This library is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU Lesser General Public
	14	* License as published by the Free Software Foundation; either
	15	* version 2.1 of the License, or (at your option) any later version.
	16	*
	17	* This library is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	20	* Lesser General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU Lesser General Public
	23	* License along with this library; if not, write to the Free Software
	24	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	25	*
	26	* IBM's contributions to this file may be relicensed under LGPLv2 or later.
	27	*/
	28
	29	#include <urcu/compiler.h>
	30	#include <urcu/arch.h>
	31	#include <urcu/arch_uatomic.h>
	32
	33	#ifdef _LGPL_SOURCE
	34
	35	#include <urcu-pointer-static.h>
	36
	37	/*
	38	* rcu_dereference(ptr)
	39	*
	40	* Fetch a RCU-protected pointer. Typically used to copy the variable ptr to a
	41	* local variable.
	42	*/
	43	#define rcu_dereference _rcu_dereference
	44
	45	/*
	46	* rcu_cmpxchg_pointer(type *ptr, type new, type *old)
	47	* type rcu_xchg_pointer(type ptr, type new)
	48	* type rcu_set_pointer(type ptr, type new)
	49	*
	50	* RCU pointer updates.
	51	* @ptr: address of the pointer to modify
	52	* @new: new pointer value
	53	* @old: old pointer value (expected)
	54	*
	55	* return: old pointer value
	56	*/
	57	#define rcu_cmpxchg_pointer _rcu_cmpxchg_pointer
	58	#define rcu_xchg_pointer _rcu_xchg_pointer
	59	#define rcu_set_pointer _rcu_set_pointer
	60
	61	/*
	62	* type rcu_publish_content(type ptr, type new)
	63	*
	64	* Exchanges the pointer and waits for quiescent state. The pointer returned
	65	* can be freed. You are encouraged to use either
	66	* - rcu_cmpxchg_pointer
	67	* - rcu_xchg_pointer
	68	* - rcu_set_pointer
	69	* with call_rcu(free, ptr) instead to deal with reclamation more efficiently.
	70	*/
	71	#define rcu_publish_content _rcu_publish_content
	72
	73	#else /* !_LGPL_SOURCE */
	74
	75	extern void rcu_dereference(void p);
	76
	77	extern void rcu_cmpxchg_pointer_sym(void p, void old, void *_new);
	78	#define rcu_cmpxchg_pointer(p, old, _new) \
	79	rcu_cmpxchg_pointer_sym((void **)(p), (old), (_new))
	80
	81	extern void rcu_xchg_pointer_sym(void p, void v);
	82	#define rcu_xchg_pointer(p, v) \
	83	rcu_xchg_pointer_sym((void **)(p), (v))
	84
	85	extern void rcu_set_pointer_sym(void p, void v);
	86	#define rcu_set_pointer(p, v) \
	87	rcu_set_pointer_sym((void **)(p), (v))
	88
	89	extern void rcu_publish_content_sym(void p, void v);
	90	#define rcu_publish_content(p, v) \
	91	rcu_publish_content_sym((void **)(p), (v))
	92
	93	extern void rcu_assign_pointer_sym(void p, void v);
	94
	95	#endif /* !_LGPL_SOURCE */
	96
	97	/*
	98	* rcu_assign_pointer(type ptr, type new)
	99	*
	100	* Same as rcu_set_pointer, but takes the pointer to assign to rather than its
	101	* address as first parameter. Provided for compatibility with the Linux kernel
	102	* RCU semantic.
	103	*/
	104	#define rcu_assign_pointer(p, v) rcu_set_pointer((&p), (v))
	105
	106	#endif /* _URCU_POINTER_H */