mcst-linux-kernel/glibc-2.35/bits/sem.h

61 lines
2.1 KiB
C

/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_SEM_H
# error "Never include <bits/sem.h> directly; use <sys/sem.h> instead."
#endif
#include <sys/types.h>
/* Flags for `semop'. */
#define SEM_UNDO 0x1000 /* undo the operation on exit */
/* Commands for `semctl'. */
#define GETPID 11 /* get sempid */
#define GETVAL 12 /* get semval */
#define GETALL 13 /* get all semval's */
#define GETNCNT 14 /* get semncnt */
#define GETZCNT 15 /* get semzcnt */
#define SETVAL 16 /* set semval */
#define SETALL 17 /* set all semval's */
/* Data structure describing a set of semaphores. */
struct semid_ds
{
struct ipc_perm sem_perm; /* operation permission struct */
__time_t sem_otime; /* last semop() time */
__time_t sem_ctime; /* last time changed by semctl() */
unsigned short int sem_nsems; /* number of semaphores in set */
};
/* The user should define a union like the following to use it for arguments
for `semctl'.
union semun
{
int val; <= value for SETVAL
struct semid_ds *buf; <= buffer for IPC_STAT & IPC_SET
unsigned short int *array; <= array for GETALL & SETALL
struct seminfo *__buf; <= buffer for IPC_INFO
};
Previous versions of this file used to define this union but this is
incorrect. One can test the macro _SEM_SEMUN_UNDEFINED to see whether
one must define the union or not. */
#define _SEM_SEMUN_UNDEFINED 1