nptl/semaphore.h

   1 /* Copyright (C) 2002, 2003, 2011 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _SEMAPHORE_H
  20 #define _SEMAPHORE_H    1
  21
  22 #include <features.h>
  23 #include <sys/types.h>
  24 #ifdef __USE_XOPEN2K
  25 # define __need_timespec
  26 # include <time.h>
  27 #endif
  28
  29 /* Get the definition for sem_t.  */
  30 #include <bits/semaphore.h>
  31
  32
  33 __BEGIN_DECLS
  34
  35 /* Initialize semaphore object SEM to VALUE.  If PSHARED then share it
  36    with other processes.  */
  37 extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value)
  38      __THROW;
  39 /* Free resources associated with semaphore object SEM.  */
  40 extern int sem_destroy (sem_t *__sem) __THROW;
  41
  42 /* Open a named semaphore NAME with open flags OFLAG.  */
  43 extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW;
  44
  45 /* Close descriptor for named semaphore SEM.  */
  46 extern int sem_close (sem_t *__sem) __THROW;
  47
  48 /* Remove named semaphore NAME.  */
  49 extern int sem_unlink (__const char *__name) __THROW;
  50
  51 /* Wait for SEM being posted.
  52
  53    This function is a cancellation point and therefore not marked with
  54    __THROW.  */
  55 extern int sem_wait (sem_t *__sem);
  56
  57 #ifdef __USE_XOPEN2K
  58 /* Similar to `sem_wait' but wait only until ABSTIME.
  59
  60    This function is a cancellation point and therefore not marked with
  61    __THROW.  */
  62 extern int sem_timedwait (sem_t *__restrict __sem,
  63                           __const struct timespec *__restrict __abstime);
  64 #endif
  65
  66 /* Test whether SEM is posted.  */
  67 extern int sem_trywait (sem_t *__sem) __THROWNL;
  68
  69 /* Post SEM.  */
  70 extern int sem_post (sem_t *__sem) __THROWNL;
  71
  72 /* Get current value of SEM and store it in *SVAL.  */
  73 extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval)
  74      __THROW;
  75
  76
  77 __END_DECLS
  78
  79 #endif  /* semaphore.h */