0p:semaphore.h

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      semaphore.h - semaphores (REALTIME)
      
      #include <semaphore.h>

Contents

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 pro-
      vided.
 
             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.

RELATED

      <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,  Stan-
      dard  for  Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifica-
      tions 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)

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