1 /*- 2 * Copyright (c) 2000 Jake Burkholder <jake@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 AUTHOR 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 _SYS_CONDVAR_H_ 30 #define _SYS_CONDVAR_H_ 31 32 #ifndef LOCORE 33 #include <sys/queue.h> 34 35 struct lock_object; 36 struct thread; 37 38 TAILQ_HEAD(cv_waitq, thread); 39 40 /* 41 * Condition variable. The waiters count is protected by the mutex that 42 * protects the condition; that is, the mutex that is passed to cv_wait*() 43 * and is held across calls to cv_signal() and cv_broadcast(). It is an 44 * optimization to avoid looking up the sleep queue if there are no waiters. 45 */ 46 struct cv { 47 const char *cv_description; 48 int cv_waiters; 49 }; 50 51 #ifdef _KERNEL 52 void cv_init(struct cv *cvp, const char *desc); 53 void cv_destroy(struct cv *cvp); 54 55 void _cv_wait(struct cv *cvp, struct lock_object *lock); 56 void _cv_wait_unlock(struct cv *cvp, struct lock_object *lock); 57 int _cv_wait_sig(struct cv *cvp, struct lock_object *lock); 58 int _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo); 59 int _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo); 60 61 void cv_signal(struct cv *cvp); 62 void cv_broadcastpri(struct cv *cvp, int pri); 63 64 #define cv_wait(cvp, lock) \ 65 _cv_wait((cvp), &(lock)->lock_object) 66 #define cv_wait_unlock(cvp, lock) \ 67 _cv_wait_unlock((cvp), &(lock)->lock_object) 68 #define cv_wait_sig(cvp, lock) \ 69 _cv_wait_sig((cvp), &(lock)->lock_object) 70 #define cv_timedwait(cvp, lock, timo) \ 71 _cv_timedwait((cvp), &(lock)->lock_object, (timo)) 72 #define cv_timedwait_sig(cvp, lock, timo) \ 73 _cv_timedwait_sig((cvp), &(lock)->lock_object, (timo)) 74 75 #define cv_broadcast(cvp) cv_broadcastpri(cvp, 0) 76 77 #define cv_wmesg(cvp) ((cvp)->cv_description) 78 79 #endif /* _KERNEL */ 80 #endif /* !LOCORE */ 81 #endif /* _SYS_CONDVAR_H_ */ 82