semaphore.h(0P) POSIX Programmer's Manual semaphore.h(0P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
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NAMEsemaphore.h — semaphores
SYNOPSIS
#include <semaphore.h>
DESCRIPTION
The <semaphore.h> header shall define the sem_t type, used in perform‐
ing 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 <semaphore.h> header shall define the symbolic constant SEM_FAILED
which shall have type sem_t *.
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 <fcntl.h> and <time.h> headers.
The following sections are informative.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
<fcntl.h>, <sys_types.h>, <time.h>
The System Interfaces volume of POSIX.1‐2008, sem_close(),
sem_destroy(), sem_getvalue(), sem_init(), sem_open(), sem_post(),
sem_timedwait(), sem_trywait(), sem_unlink()COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 semaphore.h(0P)
