[urcu.git] / urcu / lfstack.h

#ifndef _URCU_LFSTACK_H
#define _URCU_LFSTACK_H

/*
 * lfstack.h
 *
 * Userspace RCU library - Lock-Free Stack
 *
 * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * 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
 */

#ifdef __cplusplus
extern "C" {
#endif

struct cds_lfs_node {
	struct cds_lfs_node *next;
};

struct cds_lfs_stack {
	struct cds_lfs_node *head;
};

#ifdef _LGPL_SOURCE

#include <urcu/static/lfstack.h>

#define cds_lfs_node_init		_cds_lfs_node_init
#define cds_lfs_init			_cds_lfs_init
#define cds_lfs_push			_cds_lfs_push
#define cds_lfs_pop			_cds_lfs_pop

#else /* !_LGPL_SOURCE */

extern void cds_lfs_node_init(struct cds_lfs_node *node);
extern void cds_lfs_init(struct cds_lfs_stack *s);

/*
 * cds_lfs_push: push a node into the stack.
 *
 * Does not require any synchronization with other push nor pop.
 *
 * Returns 0 if the stack was empty prior to adding the node.
 * Returns non-zero otherwise.
 */
extern int cds_lfs_push(struct cds_lfs_stack *s,
			struct cds_lfs_node *node);

/*
 * cds_lfs_pop: pop a node from the stack.
 *
 * Returns NULL if stack is empty.
 *
 * cds_lfs_pop needs to be synchronized using one of the following
 * techniques:
 *
 * 1) Calling cds_lfs_pop under rcu read lock critical section. The
 *    caller must wait for a grace period to pass before freeing the
 *    returned node or modifying the cds_lfs_node structure.
 * 2) Using mutual exclusion (e.g. mutexes) to protect cds_lfs_pop
 *    callers.
 * 3) Ensuring that only ONE thread can call cds_lfs_pop().
 *    (multi-provider/single-consumer scheme).
 */
extern struct cds_lfs_node *cds_lfs_pop(struct cds_lfs_stack *s);

#endif /* !_LGPL_SOURCE */

#ifdef __cplusplus
}
#endif

#endif /* _URCU_LFSTACK_H */
Commit	Line	Data
	1	#ifndef _URCU_LFSTACK_H
	2	#define _URCU_LFSTACK_H
	3
	4	/*
	5	* lfstack.h
	6	*
	7	* Userspace RCU library - Lock-Free Stack
	8	*
	9	* Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* This library is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU Lesser General Public
	13	* License as published by the Free Software Foundation; either
	14	* version 2.1 of the License, or (at your option) any later version.
	15	*
	16	* This library is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	19	* Lesser General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU Lesser General Public
	22	* License along with this library; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	24	*/
	25
	26	#ifdef __cplusplus
	27	extern "C" {
	28	#endif
	29
	30	struct cds_lfs_node {
	31	struct cds_lfs_node *next;
	32	};
	33
	34	struct cds_lfs_stack {
	35	struct cds_lfs_node *head;
	36	};
	37
	38	#ifdef _LGPL_SOURCE
	39
	40	#include <urcu/static/lfstack.h>
	41
	42	#define cds_lfs_node_init _cds_lfs_node_init
	43	#define cds_lfs_init _cds_lfs_init
	44	#define cds_lfs_push _cds_lfs_push
	45	#define cds_lfs_pop _cds_lfs_pop
	46
	47	#else /* !_LGPL_SOURCE */
	48
	49	extern void cds_lfs_node_init(struct cds_lfs_node *node);
	50	extern void cds_lfs_init(struct cds_lfs_stack *s);
	51
	52	/*
	53	* cds_lfs_push: push a node into the stack.
	54	*
	55	* Does not require any synchronization with other push nor pop.
	56	*
	57	* Returns 0 if the stack was empty prior to adding the node.
	58	* Returns non-zero otherwise.
	59	*/
	60	extern int cds_lfs_push(struct cds_lfs_stack *s,
	61	struct cds_lfs_node *node);
	62
	63	/*
	64	* cds_lfs_pop: pop a node from the stack.
	65	*
	66	* Returns NULL if stack is empty.
	67	*
	68	* cds_lfs_pop needs to be synchronized using one of the following
	69	* techniques:
	70	*
	71	* 1) Calling cds_lfs_pop under rcu read lock critical section. The
	72	* caller must wait for a grace period to pass before freeing the
	73	* returned node or modifying the cds_lfs_node structure.
	74	* 2) Using mutual exclusion (e.g. mutexes) to protect cds_lfs_pop
	75	* callers.
	76	* 3) Ensuring that only ONE thread can call cds_lfs_pop().
	77	* (multi-provider/single-consumer scheme).
	78	*/
	79	extern struct cds_lfs_node cds_lfs_pop(struct cds_lfs_stack s);
	80
	81	#endif /* !_LGPL_SOURCE */
	82
	83	#ifdef __cplusplus
	84	}
	85	#endif
	86
	87	#endif /* _URCU_LFSTACK_H */