2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #ifndef _OPENSOLARIS_SYS_RWLOCK_H_
30 #define _OPENSOLARIS_SYS_RWLOCK_H_
32 #include <sys/param.h>
40 RW_DRIVER = 2, /* driver (DDI) rwlock */
41 RW_DEFAULT = 4 /* kernel default rwlock */
49 typedef struct sx krwlock_t;
52 #define RW_FLAGS (SX_DUPOK | SX_NOWITNESS)
54 #define RW_FLAGS (SX_DUPOK)
57 #define RW_READ_HELD(x) (rw_read_held((x)))
58 #define RW_WRITE_HELD(x) (rw_write_held((x)))
59 #define RW_LOCK_HELD(x) (rw_lock_held((x)))
60 #define RW_ISWRITER(x) (rw_iswriter(x))
62 #define rw_init(lock, desc, type, arg) do { \
63 KASSERT(((lock)->lock_object.lo_flags & LO_ALLMASK) != \
64 LO_EXPECTED, ("lock %s already initialized", #lock)); \
65 bzero((lock), sizeof(struct sx)); \
66 sx_init_flags((lock), "zfs:" #lock, RW_FLAGS); \
68 #define rw_destroy(lock) sx_destroy(lock)
69 #define rw_enter(lock, how) do { \
70 if ((how) == RW_READER) \
72 else /* if ((how) == RW_WRITER) */ \
75 #define rw_tryenter(lock, how) ((how) == RW_READER ? sx_try_slock(lock) : sx_try_xlock(lock))
76 #define rw_exit(lock) sx_unlock(lock)
77 #define rw_downgrade(lock) sx_downgrade(lock)
78 #define rw_tryupgrade(lock) sx_try_upgrade(lock)
79 #define rw_read_held(lock) ((lock)->sx_lock != SX_LOCK_UNLOCKED && ((lock)->sx_lock & SX_LOCK_SHARED))
80 #define rw_write_held(lock) sx_xlocked(lock)
81 #define rw_lock_held(lock) (rw_read_held(lock) || rw_write_held(lock))
82 #define rw_iswriter(lock) sx_xlocked(lock)
83 /* TODO: Change to sx_xholder() once it is moved from kern_sx.c to sx.h. */
84 #define rw_owner(lock) ((lock)->sx_lock & SX_LOCK_SHARED ? NULL : (struct thread *)SX_OWNER((lock)->sx_lock))
86 #endif /* defined(_KERNEL) */
88 #endif /* _OPENSOLARIS_SYS_RWLOCK_H_ */