[mirror_zfs.git] / include / os / freebsd / spl / sys / rwlock.h

/*
 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#ifndef _OPENSOLARIS_SYS_RWLOCK_H_
#define	_OPENSOLARIS_SYS_RWLOCK_H_

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/sx.h>

typedef enum {
	RW_DEFAULT = 4		/* kernel default rwlock */
} krw_type_t;


typedef enum {
	RW_NONE		= 0,
	RW_WRITER	= 1,
	RW_READER	= 2
} krw_t;

typedef	struct sx	krwlock_t;

#ifndef OPENSOLARIS_WITNESS
#define	RW_FLAGS	(SX_DUPOK | SX_NOWITNESS)
#else
#define	RW_FLAGS	(SX_DUPOK)
#endif

#define	RW_READ_HELD(x)		(rw_read_held((x)))
#define	RW_WRITE_HELD(x)	(rw_write_held((x)))
#define	RW_LOCK_HELD(x)		(rw_lock_held((x)))
#define	RW_ISWRITER(x)		(rw_iswriter(x))
#define	rw_init(lock, desc, type, arg)	do {				\
	const char *_name;						\
	ASSERT((type) == 0 || (type) == RW_DEFAULT);			\
	KASSERT(((lock)->lock_object.lo_flags & LO_ALLMASK) !=		\
	    LO_EXPECTED, ("lock %s already initialized", #lock));	\
	bzero((lock), sizeof (struct sx));				\
	for (_name = #lock; *_name != '\0'; _name++) {			\
		if (*_name >= 'a' && *_name <= 'z')			\
			break;						\
	}								\
	if (*_name == '\0')						\
		_name = #lock;						\
	sx_init_flags((lock), _name, RW_FLAGS);				\
} while (0)
#define	rw_destroy(lock)	sx_destroy(lock)
#define	rw_enter(lock, how)	do {					\
	if ((how) == RW_READER)						\
		sx_slock(lock);						\
	else /* if ((how) == RW_WRITER) */				\
		sx_xlock(lock);						\
	} while (0)

#define	rw_tryenter(lock, how)			   \
	((how) == RW_READER ? sx_try_slock(lock) : sx_try_xlock(lock))
#define	rw_exit(lock)		sx_unlock(lock)
#define	rw_downgrade(lock)	sx_downgrade(lock)
#define	rw_tryupgrade(lock)	sx_try_upgrade(lock)
#define	rw_read_held(lock)					  \
	((lock)->sx_lock != SX_LOCK_UNLOCKED &&	  \
	    ((lock)->sx_lock & SX_LOCK_SHARED))
#define	rw_write_held(lock)	sx_xlocked(lock)
#define	rw_lock_held(lock)	(rw_read_held(lock) || rw_write_held(lock))
#define	rw_iswriter(lock)	sx_xlocked(lock)
#define	rw_owner(lock)		sx_xholder(lock)

#endif	/* _OPENSOLARIS_SYS_RWLOCK_H_ */
Commit	Line	Data
9f0a21e6 MM	1	/*
	2	* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
	15	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	16	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	17	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
	18	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	19	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	20	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	21	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	24	* SUCH DAMAGE.
	25	*
	26	* $FreeBSD$
	27	*/
	28
	29	#ifndef _OPENSOLARIS_SYS_RWLOCK_H_
	30	#define _OPENSOLARIS_SYS_RWLOCK_H_
	31
	32	#include <sys/param.h>
	33	#include <sys/proc.h>
	34	#include <sys/lock.h>
	35	#include <sys/sx.h>
	36
	37	typedef enum {
	38	RW_DEFAULT = 4 /* kernel default rwlock */
	39	} krw_type_t;
	40
	41
	42	typedef enum {
	43	RW_NONE = 0,
	44	RW_WRITER = 1,
	45	RW_READER = 2
	46	} krw_t;
	47
	48	typedef struct sx krwlock_t;
	49
	50	#ifndef OPENSOLARIS_WITNESS
	51	#define RW_FLAGS (SX_DUPOK \| SX_NOWITNESS)
	52	#else
	53	#define RW_FLAGS (SX_DUPOK)
	54	#endif
	55
	56	#define RW_READ_HELD(x) (rw_read_held((x)))
	57	#define RW_WRITE_HELD(x) (rw_write_held((x)))
	58	#define RW_LOCK_HELD(x) (rw_lock_held((x)))
	59	#define RW_ISWRITER(x) (rw_iswriter(x))
9f0a21e6 MM	60	#define rw_init(lock, desc, type, arg) do { \
	61	const char *_name; \
	62	ASSERT((type) == 0 \|\| (type) == RW_DEFAULT); \
	63	KASSERT(((lock)->lock_object.lo_flags & LO_ALLMASK) != \
	64	LO_EXPECTED, ("lock %s already initialized", #lock)); \
7ada752a	65	bzero((lock), sizeof (struct sx)); \
9f0a21e6 MM	66	for (_name = #lock; *_name != '\0'; _name++) { \
	67	if (_name >= 'a' && _name <= 'z') \
	68	break; \
	69	} \
	70	if (*_name == '\0') \
	71	_name = #lock; \
	72	sx_init_flags((lock), _name, RW_FLAGS); \
	73	} while (0)
	74	#define rw_destroy(lock) sx_destroy(lock)
	75	#define rw_enter(lock, how) do { \
	76	if ((how) == RW_READER) \
	77	sx_slock(lock); \
	78	else /* if ((how) == RW_WRITER) */ \
	79	sx_xlock(lock); \
	80	} while (0)
	81
	82	#define rw_tryenter(lock, how) \
	83	((how) == RW_READER ? sx_try_slock(lock) : sx_try_xlock(lock))
	84	#define rw_exit(lock) sx_unlock(lock)
	85	#define rw_downgrade(lock) sx_downgrade(lock)
	86	#define rw_tryupgrade(lock) sx_try_upgrade(lock)
	87	#define rw_read_held(lock) \
	88	((lock)->sx_lock != SX_LOCK_UNLOCKED && \
7ada752a	89	((lock)->sx_lock & SX_LOCK_SHARED))
9f0a21e6 MM	90	#define rw_write_held(lock) sx_xlocked(lock)
	91	#define rw_lock_held(lock) (rw_read_held(lock) \|\| rw_write_held(lock))
	92	#define rw_iswriter(lock) sx_xlocked(lock)
	93	#define rw_owner(lock) sx_xholder(lock)
	94
9f0a21e6	95	#endif /* _OPENSOLARIS_SYS_RWLOCK_H_ */