1: /* Copyright (C) 1995, 1996, 1997, 1998
    2:    Free Software Foundation, Inc.
    3:    This file is part of the GNU C Library.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #ifndef _SYS_SEM_H
   21: # error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
   22: #endif
   23: 
   24: #include <sys/types.h>
   25: 
   26: /* Flags for `semop'.  */
   27: #define SEM_UNDO        0x1000         /* undo the operation on exit */
   28: 
   29: /* Commands for `semctl'.  */
   30: #define GETPID          11              /* get sempid */
   31: #define GETVAL          12              /* get semval */
   32: #define GETALL          13              /* get all semval's */
   33: #define GETNCNT         14             /* get semncnt */
   34: #define GETZCNT         15             /* get semzcnt */
   35: #define SETVAL          16              /* set semval */
   36: #define SETALL          17              /* set all semval's */
   37: 
   38: 
   39: /* Data structure describing a set of semaphores.  */
   40: struct semid_ds
   41: {
   42:   struct ipc_perm sem_perm;             /* operation permission struct */
   43:   __time_t sem_otime;                   /* last semop() time */
   44:   __time_t sem_ctime;                   /* last time changed by semctl() */
   45:   unsigned short int sem_nsems;         /* number of semaphores in set */
   46: };
   47: 
   48: /* The user should define a union like the following to use it for arguments
   49:    for `semctl'.
   50: 
   51:    union semun
   52:    {
   53:      int val;                           <= value for SETVAL
   54:      struct semid_ds *buf;              <= buffer for IPC_STAT & IPC_SET
   55:      unsigned short int *array;         <= array for GETALL & SETALL
   56:      struct seminfo *__buf;             <= buffer for IPC_INFO
   57:    };
   58: 
   59:    Previous versions of this file used to define this union but this is
   60:    incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
   61:    one must define the union or not.  */
   62: #define _SEM_SEMUN_UNDEFINED    1