1 /* 2 * Copyright (c) 2001, 2003 Daniel Eischen <deischen@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 AUTHOR 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 _LOCK_H_ 30 #define _LOCK_H_ 31 32 struct lockreq; 33 struct lockuser; 34 struct lock; 35 36 enum lock_type { 37 LCK_DEFAULT = 0x0000, /* default is FIFO spin locks */ 38 LCK_PRIORITY = 0x0001, 39 LCK_ADAPTIVE = 0x0002 /* call user-supplied handlers */ 40 }; 41 42 typedef void lock_handler_t(struct lock *, struct lockuser *); 43 44 struct lock { 45 struct lockreq *l_head; 46 struct lockreq *l_tail; /* only used for priority locks */ 47 enum lock_type l_type; 48 lock_handler_t *l_wait; /* only used for adaptive locks */ 49 lock_handler_t *l_wakeup; /* only used for adaptive locks */ 50 }; 51 52 /* Try to make this >= CACHELINESIZE */ 53 struct lockreq { 54 struct lockuser *lr_watcher; /* only used for priority locks */ 55 struct lockuser *lr_owner; /* only used for priority locks */ 56 volatile int lr_locked; /* lock granted = 0, busy otherwise */ 57 volatile int lr_active; /* non-zero if the lock is last lock for thread */ 58 }; 59 60 struct lockuser { 61 struct lockreq *lu_myreq; /* request to give up/trade */ 62 struct lockreq *lu_watchreq; /* watch this request */ 63 int lu_priority; /* only used for priority locks */ 64 void *lu_private1; /* private{1,2} are initialized to */ 65 void *lu_private2; /* NULL and can be used by caller */ 66 #define lu_private lu_private1 67 }; 68 69 #define _LCK_INITIALIZER(lck_req) { &lck_req, NULL, LCK_DEFAULT, \ 70 NULL, NULL } 71 #define _LCK_REQUEST_INITIALIZER { 0, NULL, NULL, 0 } 72 73 #define _LCK_BUSY(lu) ((lu)->lu_watchreq->lr_locked != 0) 74 #define _LCK_ACTIVE(lu) ((lu)->lu_watchreq->lr_active != 0) 75 #define _LCK_GRANTED(lu) ((lu)->lu_watchreq->lr_locked == 3) 76 77 #define _LCK_SET_PRIVATE(lu, p) (lu)->lu_private = (void *)(p) 78 #define _LCK_GET_PRIVATE(lu) (lu)->lu_private 79 #define _LCK_SET_PRIVATE2(lu, p) (lu)->lu_private2 = (void *)(p) 80 #define _LCK_GET_PRIVATE2(lu) (lu)->lu_private2 81 82 void _lock_acquire(struct lock *, struct lockuser *, int); 83 void _lock_destroy(struct lock *); 84 void _lock_grant(struct lock *, struct lockuser *); 85 int _lock_init(struct lock *, enum lock_type, 86 lock_handler_t *, lock_handler_t *, void *(size_t, size_t)); 87 int _lock_reinit(struct lock *, enum lock_type, 88 lock_handler_t *, lock_handler_t *); 89 void _lock_release(struct lock *, struct lockuser *); 90 int _lockuser_init(struct lockuser *lu, void *priv); 91 void _lockuser_destroy(struct lockuser *lu); 92 int _lockuser_reinit(struct lockuser *lu, void *priv); 93 void _lockuser_setactive(struct lockuser *lu, int active); 94 95 #endif 96