| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 1995-2015 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 | unsigned short int sem_nsems; /* number of semaphores in set */ |
| 44 | }; |
| 45 | |
| 46 | /* The user should define a union like the following to use it for arguments |
| 47 | for `semctl'. |
| 48 | |
| 49 | union semun |
| 50 | { |
| 51 | int val; <= value for SETVAL |
| 52 | struct semid_ds *buf; <= buffer for IPC_STAT & IPC_SET |
| 53 | unsigned short int *array; <= array for GETALL & SETALL |
| 54 | struct seminfo *__buf; <= buffer for IPC_INFO |
| 55 | }; |
| 56 | |
| 57 | Previous versions of this file used to define this union but this is |
| 58 | incorrect. One can test the macro _SEM_SEMUN_UNDEFINED to see whether |
| 59 | one must define the union or not. */ |
| 60 | #define _SEM_SEMUN_UNDEFINED 1 |