xenial (7) semaphore.h.7posix.gz

Provided by: manpages-posix-dev_2013a-1_all bug

PROLOG
       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
       semaphore.h — semaphores


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 <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()


       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 .