freebsd-nq/sys/sys/semaphore.h
John Baldwin f4c1db8901 Change SEM_VALUE_MAX (maximum value of a POSIX semaphore) from UINT_MAX
to INT_MAX.  Otherwise, a process could create a semaphore (or increase
its value via ksem_post()) beyond INT_MAX and sem_getvalue() would return
a negative value.  sem_getvalue() is only supposed to return a negative
value if that is the number of waiters for that semaphore.

MFC after:	2 weeks
2008-06-26 13:51:25 +00:00

70 lines
2.5 KiB
C

/*-
* Copyright (c) 1996, 1997
* HD Associates, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by HD Associates, Inc
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/* semaphore.h: POSIX 1003.1b semaphores */
#ifndef _SEMAPHORE_H_
#define _SEMAPHORE_H_
#include <machine/_limits.h>
/* Opaque type definition. */
struct sem;
typedef struct sem * sem_t;
#define SEM_FAILED ((sem_t *)0)
#define SEM_VALUE_MAX __INT_MAX
#ifndef _KERNEL
#include <sys/cdefs.h>
struct timespec;
__BEGIN_DECLS
int sem_close(sem_t *);
int sem_destroy(sem_t *);
int sem_getvalue(sem_t * __restrict, int * __restrict);
int sem_init(sem_t *, int, unsigned int);
sem_t *sem_open(const char *, int, ...);
int sem_post(sem_t *);
int sem_timedwait(sem_t * __restrict, const struct timespec * __restrict);
int sem_trywait(sem_t *);
int sem_unlink(const char *);
int sem_wait(sem_t *);
__END_DECLS
#endif
#endif /* !_SEMAPHORE_H_ */