src/sys/sys/shm.h

152 lines
4.9 KiB
C

/* $OpenBSD: shm.h,v 1.30 2021/03/10 10:21:47 jsg Exp $ */
/* $NetBSD: shm.h,v 1.20 1996/04/09 20:55:35 cgd Exp $ */
/*
* Copyright (c) 1994 Adam Glass
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Adam Glass.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* As defined+described in "X/Open System Interfaces and Headers"
* Issue 4, p. XXX
*/
#ifndef _SYS_SHM_H_
#define _SYS_SHM_H_
#ifndef _SYS_IPC_H_
#include <sys/ipc.h>
#endif
#if __BSD_VISIBLE
/* shm-specific sysctl variables corresponding to members of struct shminfo */
#define KERN_SHMINFO_SHMMAX 1 /* int: max shm segment size (bytes) */
#define KERN_SHMINFO_SHMMIN 2 /* int: min shm segment size (bytes) */
#define KERN_SHMINFO_SHMMNI 3 /* int: max number of shm identifiers */
#define KERN_SHMINFO_SHMSEG 4 /* int: max shm segments per process */
#define KERN_SHMINFO_SHMALL 5 /* int: max amount of shm (pages) */
#define KERN_SHMINFO_MAXID 6 /* number of valid shared memory ids */
#define CTL_KERN_SHMINFO_NAMES { \
{ 0, 0 }, \
{ "shmmax", CTLTYPE_INT }, \
{ "shmmin", CTLTYPE_INT }, \
{ "shmmni", CTLTYPE_INT }, \
{ "shmseg", CTLTYPE_INT }, \
{ "shmall", CTLTYPE_INT }, \
}
/*
* Old (deprecated) access mode definitions--do not use.
* Provided for compatibility with old code only.
*/
#define SHM_R IPC_R
#define SHM_W IPC_W
#endif /* __BSD_VISIBLE */
/*
* Shared memory operation flags for shmat(2).
*/
#define SHM_RDONLY 010000 /* Attach read-only (else read-write) */
#define SHM_RND 020000 /* Round attach address to SHMLBA */
/*
* Shared memory specific control commands for shmctl().
* We accept but ignore these (XXX).
*/
#define SHM_LOCK 3 /* Lock segment in memory. */
#define SHM_UNLOCK 4 /* Unlock a segment locked by SHM_LOCK. */
/*
* Segment low boundary address multiple
*/
#define SHMLBA (1U << _MAX_PAGE_SHIFT)
typedef short shmatt_t;
struct shmid_ds {
struct ipc_perm shm_perm; /* operation permission structure */
int shm_segsz; /* size of segment in bytes */
pid_t shm_lpid; /* process ID of last shm op */
pid_t shm_cpid; /* process ID of creator */
shmatt_t shm_nattch; /* number of current attaches */
time_t shm_atime; /* time of last shmat() */
long __shm_atimensec;
time_t shm_dtime; /* time of last shmdt() */
long __shm_dtimensec;
time_t shm_ctime; /* time of last change by shmctl() */
long __shm_ctimensec;
void *shm_internal; /* implementation specific data */
};
#if __BSD_VISIBLE
/*
* System V style catch-all structure for shared memory constants that
* might be of interest to user programs. Do we really want/need this?
*/
struct shminfo {
int shmmax; /* max shared memory segment size (bytes) */
int shmmin; /* min shared memory segment size (bytes) */
int shmmni; /* max number of shared memory identifiers */
int shmseg; /* max shared memory segments per process */
int shmall; /* max amount of shared memory (pages) */
};
struct shm_sysctl_info {
struct shminfo shminfo;
struct shmid_ds shmids[1];
};
#endif /* __BSD_VISIBLE */
#ifdef _KERNEL
extern struct shminfo shminfo;
extern struct shmid_ds **shmsegs;
struct proc;
struct vmspace;
void shminit(void);
void shmfork(struct vmspace *, struct vmspace *);
void shmexit(struct vmspace *);
int sysctl_sysvshm(int *, u_int, void *, size_t *, void *, size_t);
#else /* !_KERNEL */
__BEGIN_DECLS
void *shmat(int, const void *, int);
int shmctl(int, int, struct shmid_ds *);
int shmdt(const void *);
int shmget(key_t, size_t, int);
__END_DECLS
#endif /* !_KERNEL */
#endif /* !_SYS_SHM_H_ */