sysdeps/gnu/bits/sem.h

   1 /* Copyright (C) 1995-2019 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_SEM_H
  19 # error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
  20 #endif
  21
  22 #include <sys/types.h>
  23
  24 /* Flags for `semop'.  */
  25 #define SEM_UNDO        0x1000          /* undo the operation on exit */
  26
  27 /* Commands for `semctl'.  */
  28 #define GETPID          11              /* get sempid */
  29 #define GETVAL          12              /* get semval */
  30 #define GETALL          13              /* get all semval's */
  31 #define GETNCNT         14              /* get semncnt */
  32 #define GETZCNT         15              /* get semzcnt */
  33 #define SETVAL          16              /* set semval */
  34 #define SETALL          17              /* set all semval's */
  35
  36
  37 /* Data structure describing a set of semaphores.  */
  38 struct semid_ds
  39 {
  40   struct ipc_perm sem_perm;             /* operation permission struct */
  41   __time_t sem_otime;                   /* last semop() time */
  42   __time_t sem_ctime;                   /* last time changed by semctl() */
  43   struct sem *__sembase;                /* ptr to first semaphore in array */
  44   struct __sem_queue *__sem_pending;    /* pending operations */
  45   struct __sem_queue *__sem_pending_last;/* last pending operation */
  46   struct __sem_undo *__undo;            /* ondo requests on this array */
  47   unsigned short int sem_nsems;         /* number of semaphores in set */
  48 };
  49
  50
  51 /* The user should define a union like the following to use it for arguments
  52    for `semctl'.
  53
  54    union semun
  55    {
  56      int val;                           <= value for SETVAL
  57      struct semid_ds *buf;              <= buffer for IPC_STAT & IPC_SET
  58      unsigned short int *array;         <= array for GETALL & SETALL
  59      struct seminfo *__buf;             <= buffer for IPC_INFO
  60    };
  61
  62    Previous versions of this file used to define this union but this is
  63    incorrect.  One can test the macro _SEM_SEMUN_UNDEFINED to see whether
  64    one must define the union or not.  */
  65 #define _SEM_SEMUN_UNDEFINED    1
  66
  67 #ifdef __USE_MISC
  68
  69 /* ipcs ctl cmds */
  70 # define SEM_STAT 18
  71 # define SEM_INFO 19
  72
  73 struct  seminfo
  74 {
  75   int semmap;
  76   int semmni;
  77   int semmns;
  78   int semmnu;
  79   int semmsl;
  80   int semopm;
  81   int semume;
  82   int semusz;
  83   int semvmx;
  84   int semaem;
  85 };
  86
  87 #endif /* __USE_MISC */