1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (C) 2001 Jason Evans <jasone@freebsd.org>. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice(s), this list of conditions and the following disclaimer as 11 * the first lines of this file unmodified other than the possible 12 * addition of one or more copyright notices. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice(s), this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 27 * DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 #ifndef _SYS_SEMA_H_ 33 #define _SYS_SEMA_H_ 34 35 #include <sys/queue.h> 36 #include <sys/_lock.h> 37 #include <sys/_mutex.h> 38 #include <sys/condvar.h> 39 40 struct sema { 41 struct mtx sema_mtx; /* General protection lock. */ 42 struct cv sema_cv; /* Waiters. */ 43 int sema_waiters; /* Number of waiters. */ 44 int sema_value; /* Semaphore value. */ 45 }; 46 47 #ifdef _KERNEL 48 void sema_init(struct sema *sema, int value, const char *description); 49 void sema_destroy(struct sema *sema); 50 void _sema_post(struct sema *sema, const char *file, int line); 51 void _sema_wait(struct sema *sema, const char *file, int line); 52 int _sema_timedwait(struct sema *sema, int timo, const char *file, int 53 line); 54 int _sema_trywait(struct sema *sema, const char *file, int line); 55 int sema_value(struct sema *sema); 56 57 #define sema_post(sema) _sema_post((sema), LOCK_FILE, LOCK_LINE) 58 #define sema_wait(sema) _sema_wait((sema), LOCK_FILE, LOCK_LINE) 59 #define sema_timedwait(sema, timo) \ 60 _sema_timedwait((sema), (timo), LOCK_FILE, LOCK_LINE) 61 #define sema_trywait(sema) _sema_trywait((sema), LOCK_FILE, LOCK_LINE) 62 63 #endif /* _KERNEL */ 64 #endif /* _SYS_SEMA_H_ */ 65