root/sys/shm.h

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    1 /*      $OpenBSD: shm.h,v 1.21 2007/05/29 10:44:28 sturm Exp $  */
    2 /*      $NetBSD: shm.h,v 1.20 1996/04/09 20:55:35 cgd Exp $     */
    3 
    4 /*
    5  * Copyright (c) 1994 Adam Glass
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. All advertising materials mentioning features or use of this software
   17  *    must display the following acknowledgement:
   18  *      This product includes software developed by Adam Glass.
   19  * 4. The name of the author may not be used to endorse or promote products
   20  *    derived from this software without specific prior written permission
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   32  */
   33 
   34 /*
   35  * As defined+described in "X/Open System Interfaces and Headers"
   36  *                         Issue 4, p. XXX
   37  */
   38 
   39 #ifndef _SYS_SHM_H_
   40 #define _SYS_SHM_H_
   41 
   42 #include <sys/cdefs.h>
   43 #ifndef _SYS_IPC_H_
   44 #include <sys/ipc.h>
   45 #endif
   46 
   47 #if __BSD_VISIBLE
   48 
   49 /* shm-specific sysctl variables corresponding to members of struct shminfo */
   50 #define KERN_SHMINFO_SHMMAX     1       /* int: max shm segment size (bytes) */
   51 #define KERN_SHMINFO_SHMMIN     2       /* int: min shm segment size (bytes) */
   52 #define KERN_SHMINFO_SHMMNI     3       /* int: max number of shm identifiers */
   53 #define KERN_SHMINFO_SHMSEG     4       /* int: max shm segments per process */
   54 #define KERN_SHMINFO_SHMALL     5       /* int: max amount of shm (pages) */
   55 #define KERN_SHMINFO_MAXID      6       /* number of valid shared memory ids */
   56 
   57 #define CTL_KERN_SHMINFO_NAMES { \
   58         { 0, 0 }, \
   59         { "shmmax", CTLTYPE_INT }, \
   60         { "shmmin", CTLTYPE_INT }, \
   61         { "shmmni", CTLTYPE_INT }, \
   62         { "shmseg", CTLTYPE_INT }, \
   63         { "shmall", CTLTYPE_INT }, \
   64 }
   65 
   66 /*
   67  * Old (deprecated) access mode definitions--do not use.
   68  * Provided for compatibility with old code only.
   69  */
   70 #define SHM_R           IPC_R
   71 #define SHM_W           IPC_W
   72 
   73 #endif /* __BSD_VISIBLE */
   74 
   75 /*
   76  * Shared memory operation flags for shmat(2).
   77  */
   78 #define SHM_RDONLY      010000  /* Attach read-only (else read-write) */
   79 #define SHM_RND         020000  /* Round attach address to SHMLBA */
   80 #ifdef _KERNEL
   81 #define _SHM_RMLINGER   040000  /* Attach even if segment removed */
   82 #endif
   83 
   84 /*
   85  * Shared memory specific control commands for shmctl().
   86  * We accept but ignore these (XXX).
   87  */
   88 #define SHM_LOCK        3       /* Lock segment in memory. */
   89 #define SHM_UNLOCK      4       /* Unlock a segment locked by SHM_LOCK. */
   90 
   91 /*
   92  * Segment low boundry address multiple
   93  * Use PAGE_SIZE for kernel but for userland query the kernel for the value.
   94  */
   95 #if defined(_KERNEL) || defined(_STANDALONE) || defined(_LKM)
   96 #define SHMLBA          PAGE_SIZE
   97 #else
   98 #define SHMLBA          (getpagesize())
   99 #endif /* _KERNEL || _STANDALONE || _LKM */
  100 
  101 typedef short           shmatt_t;
  102 
  103 struct shmid_ds {
  104         struct ipc_perm shm_perm;       /* operation permission structure */
  105         int             shm_segsz;      /* size of segment in bytes */
  106         pid_t           shm_lpid;       /* process ID of last shm op */
  107         pid_t           shm_cpid;       /* process ID of creator */
  108         shmatt_t        shm_nattch;     /* number of current attaches */
  109         time_t          shm_atime;      /* time of last shmat() */
  110         time_t          shm_dtime;      /* time of last shmdt() */
  111         time_t          shm_ctime;      /* time of last change by shmctl() */
  112         void            *shm_internal;  /* implementation specific data */
  113 };
  114 
  115 #ifdef _KERNEL
  116 struct shmid_ds23 {
  117         struct ipc_perm23 shm_perm;     /* operation permission structure */
  118         int             shm_segsz;      /* size of segment in bytes */
  119         pid_t           shm_lpid;       /* process ID of last shm op */
  120         pid_t           shm_cpid;       /* process ID of creator */
  121         shmatt_t        shm_nattch;     /* number of current attaches */
  122         time_t          shm_atime;      /* time of last shmat() */
  123         time_t          shm_dtime;      /* time of last shmdt() */
  124         time_t          shm_ctime;      /* time of last change by shmctl() */
  125         void            *shm_internal;  /* implementation specific data */
  126 };
  127 
  128 struct shmid_ds35 {
  129         struct ipc_perm35 shm_perm;     /* operation permission structure */
  130         int               shm_segsz;    /* size of segment in bytes */
  131         pid_t             shm_lpid;     /* process ID of last shm op */
  132         pid_t             shm_cpid;     /* process ID of creator */
  133         shmatt_t          shm_nattch;   /* number of current attaches */
  134         time_t            shm_atime;    /* time of last shmat() */
  135         time_t            shm_dtime;    /* time of last shmdt() */
  136         time_t            shm_ctime;    /* time of last change by shmctl() */
  137         void              *shm_internal;/* implementation specific data */
  138 };
  139 #endif
  140 
  141 #if __BSD_VISIBLE
  142 /*
  143  * System V style catch-all structure for shared memory constants that
  144  * might be of interest to user programs.  Do we really want/need this?
  145  */
  146 struct shminfo {
  147         int     shmmax;         /* max shared memory segment size (bytes) */
  148         int     shmmin;         /* min shared memory segment size (bytes) */
  149         int     shmmni;         /* max number of shared memory identifiers */
  150         int     shmseg;         /* max shared memory segments per process */
  151         int     shmall;         /* max amount of shared memory (pages) */
  152 };
  153 
  154 struct shm_sysctl_info {
  155         struct  shminfo shminfo;
  156         struct  shmid_ds shmids[1];
  157 };
  158 #endif /* __BSD_VISIBLE */
  159 
  160 #ifdef _KERNEL
  161 extern struct shminfo shminfo;
  162 extern struct shmid_ds **shmsegs;
  163 
  164 /* initial values for machdep.c */
  165 extern int shmseg;
  166 extern int shmmaxpgs;
  167 
  168 struct proc;
  169 struct vmspace;
  170 
  171 void    shminit(void);
  172 void    shmfork(struct vmspace *, struct vmspace *);
  173 void    shmexit(struct vmspace *);
  174 int     sysctl_sysvshm(int *, u_int, void *, size_t *, void *, size_t);
  175 int     shmctl1(struct proc *, int, int, caddr_t,
  176             int (*)(const void *, void *, size_t),
  177             int (*)(const void *, void *, size_t));
  178 
  179 #else /* !_KERNEL */
  180 
  181 __BEGIN_DECLS
  182 void *shmat(int, const void *, int);
  183 int shmctl(int, int, struct shmid_ds *);
  184 int shmdt(const void *);
  185 int shmget(key_t, size_t, int);
  186 __END_DECLS
  187 
  188 #endif /* !_KERNEL */
  189 
  190 #endif /* !_SYS_SHM_H_ */

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