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 #ifdef _KERNEL 38 39 typedef enum { 40 RW_DEFAULT = 4 /* kernel default rwlock */ 41 } krw_type_t; 42 43 typedef enum { 44 RW_WRITER, 45 RW_READER 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)) 60 61 #define rw_init(lock, desc, type, arg) do { \ 62 const char *_name; \ 63 ASSERT((type) == 0 || (type) == RW_DEFAULT); \ 64 KASSERT(((lock)->lock_object.lo_flags & LO_ALLMASK) != \ 65 LO_EXPECTED, ("lock %s already initialized", #lock)); \ 66 bzero((lock), sizeof(struct sx)); \ 67 for (_name = #lock; *_name != '\0'; _name++) { \ 68 if (*_name >= 'a' && *_name <= 'z') \ 69 break; \ 70 } \ 71 if (*_name == '\0') \ 72 _name = #lock; \ 73 sx_init_flags((lock), _name, RW_FLAGS); \ 74 } while (0) 75 #define rw_destroy(lock) sx_destroy(lock) 76 #define rw_enter(lock, how) do { \ 77 if ((how) == RW_READER) \ 78 sx_slock(lock); \ 79 else /* if ((how) == RW_WRITER) */ \ 80 sx_xlock(lock); \ 81 } while (0) 82 #define rw_tryenter(lock, how) ((how) == RW_READER ? sx_try_slock(lock) : sx_try_xlock(lock)) 83 #define rw_exit(lock) sx_unlock(lock) 84 #define rw_downgrade(lock) sx_downgrade(lock) 85 #define rw_tryupgrade(lock) sx_try_upgrade(lock) 86 #define rw_read_held(lock) ((lock)->sx_lock != SX_LOCK_UNLOCKED && ((lock)->sx_lock & SX_LOCK_SHARED)) 87 #define rw_write_held(lock) sx_xlocked(lock) 88 #define rw_lock_held(lock) (rw_read_held(lock) || rw_write_held(lock)) 89 #define rw_iswriter(lock) sx_xlocked(lock) 90 #define rw_owner(lock) sx_xholder(lock) 91 92 #endif /* defined(_KERNEL) */ 93 94 #endif /* _OPENSOLARIS_SYS_RWLOCK_H_ */ 95