bits/sem.h

   1 /* Copyright (C) 1995, 1996, 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _SYS_SEM_H
  20 # error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
  21 #endif
  22
  23 #include <sys/types.h>
  24
  25 /* Flags for `semop'.  */
  26 #define SEM_UNDO        0x1000          /* undo the operation on exit */
  27
  28 /* Commands for `semctl'.  */
  29 #define GETPID          11              /* get sempid */
  30 #define GETVAL          12              /* get semval */
  31 #define GETALL          13              /* get all semval's */
  32 #define GETNCNT         14              /* get semncnt */
  33 #define GETZCNT         15              /* get semzcnt */
  34 #define SETVAL          16              /* set semval */
  35 #define SETALL          17              /* set all semval's */
  36
  37
  38 /* Data structure describing a set of semaphores.  */
  39 struct semid_ds
  40 {
  41   struct ipc_perm sem_perm;             /* operation permission struct */
  42   __time_t sem_otime;                   /* last semop() time */
  43   __time_t sem_ctime;                   /* last time changed by semctl() */
  44   unsigned short int sem_nsems;         /* number of semaphores in set */
  45 };
  46
  47 /* Union used for argument for `semctl'.  */
  48 union semun
  49 {
  50   int val;                              /* value for SETVAL */
  51   struct semid_ds *buf;                 /* buffer for IPC_STAT & IPC_SET */
  52   unsigned short int *array;            /* array for GETALL & SETALL */
  53   struct seminfo *__buf;                /* buffer for IPC_INFO */
  54  };