<semaphore.h>(P) POSIX Programmer's Manual <semaphore.h>(P)
NAME
semaphore.h - semaphores (REALTIME)
SYNOPSIS
#include <semaphore.h>
DESCRIPTION
The <semaphore.h> header shall define the sem_t type, used in performing semaphore operations. The semaphore may be implemented using a
file descriptor, in which case applications are able to open up at least a total of {OPEN_MAX} files and semaphores. The symbol SEM_FAILED
shall be defined (see sem_open()).
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
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);
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 *);
Inclusion of the <semaphore.h> header may make visible symbols defined in the headers <fcntl.h> and <sys/types.h>.
The following sections are informative.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
<fcntl.h> , <sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001, sem_destroy(), sem_getvalue(), sem_init(), sem_open(),
sem_post(), sem_timedwait(), sem_trywait(), sem_unlink(), sem_wait()
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
online at http://www.opengroup.org/unix/online.html .
IEEE
/The Open Group 2003 <semaphore.h>(P)