PROLOG | NAME | SYNOPSIS | DESCRIPTION | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

semaphore.h(0P)           POSIX Programmer's Manual          semaphore.h(0P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       semaphore.h — semaphores

SYNOPSIS         top

       #include <semaphore.h>

DESCRIPTION         top

       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 <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         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       fcntl.h(0p), sys_types.h(0p), time.h(0p)

       The System Interfaces volume of POSIX.1‐2008, sem_close(3p),
       sem_destroy(3p), sem_getvalue(3p), sem_init(3p), sem_open(3p),
       sem_post(3p), sem_timedwait(3p), sem_trywait(3p), sem_unlink(3p)

COPYRIGHT         top

       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 Electrical 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.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                     semaphore.h(0P)