bsd/sys/shm.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: shm.h,v 1.15 1994/06/29 06:45:17 cgd Exp $     */
  23
  24 /*
  25  * Copyright (c) 1994 Adam Glass
  26  * All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by Adam Glass.
  39  * 4. The name of the author may not be used to endorse or promote products
  40  *    derived from this software without specific prior written permission
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  43  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  44  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  45  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  46  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  47  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  48  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  49  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  50  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  51  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  52  */
  53
  54 /*
  55  * As defined+described in "X/Open System Interfaces and Headers"
  56  *                         Issue 4, p. XXX
  57  */
  58
  59 #ifndef _SYS_SHM_H_
  60 #define _SYS_SHM_H_
  61
  62 #include <sys/cdefs.h>
  63 #include <sys/_types.h>
  64
  65 /*
  66  * [XSI]        All of the symbols from <sys/ipc.h> SHALL be defined
  67  *              when this header is included
  68  */
  69 #include <sys/ipc.h>
  70
  71 /*
  72  * [XSI] The pid_t, time_t, key_t, and size_t types shall be defined as
  73  * described in <sys/types.h>.
  74  *
  75  * NOTE:        The definition of the key_t type is implicit from the
  76  *              inclusion of <sys/ipc.h>
  77  */
  78 #ifndef _PID_T
  79 typedef __darwin_pid_t  pid_t;
  80 #define _PID_T
  81 #endif
  82
  83 #ifndef _TIME_T
  84 #define _TIME_T
  85 typedef __darwin_time_t time_t;
  86 #endif
  87
  88 #ifndef _SIZE_T
  89 #define _SIZE_T
  90 typedef __darwin_size_t size_t;
  91 #endif
  92
  93 /*
  94  * [XSI] The unsigned integer type used for the number of current attaches
  95  * that MUST be able to store values at least as large as a type unsigned
  96  * short.
  97  */
  98 typedef unsigned short  shmatt_t;
  99
 100
 101 /*
 102  * Possible flag values which may be OR'ed into the third argument to
 103  * shmat()
 104  */
 105 #define SHM_RDONLY      010000  /* [XSI] Attach read-only (else read-write) */
 106 #define SHM_RND         020000  /* [XSI] Round attach address to SHMLBA */
 107
 108 /*
 109  * This value is symbolic, and generally not expected to be sed by user
 110  * programs directly, although such ise is permitted by the standard.  Its
 111  * value in our implementation is equal to the number of bytes per page.
 112  *
 113  * NOTE:        We DO NOT obtain this value from the appropriate system
 114  *              headers at this time, to avoid the resulting namespace
 115  *              pollution, which is why we discourages its use.
 116  */
 117 #define SHMLBA      4096        /* [XSI] Segment low boundary address multiple*/
 118
 119 /* "official" access mode definitions; somewhat braindead since you have
 120    to specify (SHM_* >> 3) for group and (SHM_* >> 6) for world permissions */
 121 #define SHM_R       (IPC_R)
 122 #define SHM_W       (IPC_W)
 123
 124 /*
 125  * Technically, we should force all code references to the new structure
 126  * definition, not in just the standards conformance case, and leave the
 127  * legacy interface there for binary compatibility only.  Currently, we
 128  * are only forcing this for programs requesting standards conformance.
 129  */
 130 #if defined(__POSIX_C_SOURCE) || defined(kernel) || defined(__LP64__)
 131 /*
 132  * Structure used internally.
 133  *
 134  * This structure is exposed because standards dictate that it is used as
 135  * the third argment to shmctl().
 136  *
 137  * NOTE:        The field shm_internal is not meaningful in user space,
 138  *              and mst not be used there.
 139  */
 140 struct __shmid_ds_new {
 141         struct __ipc_perm_new shm_perm; /* [XSI] Operation permission value */
 142         size_t          shm_segsz;      /* [XSI] Size of segment in bytes */
 143         pid_t           shm_lpid;       /* [XSI] PID of last shared memory op */
 144         pid_t           shm_cpid;       /* [XSI] PID of creator */
 145         short           shm_nattch;     /* [XSI] Number of current attaches */
 146         time_t          shm_atime;      /* [XSI] Time of last shmat() */
 147         time_t          shm_dtime;      /* [XSI] Time of last shmdt() */
 148         time_t          shm_ctime;      /* [XSI] Time of last shmctl() change */
 149         void            *shm_internal;  /* reserved for kernel use */
 150 };
 151 #define shmid_ds        __shmid_ds_new
 152 #else   /* !_POSIX_C_SOURCE */
 153 #define shmid_ds        __shmid_ds_old
 154 #endif  /* !_POSIX_C_SOURCE */
 155
 156 #if !defined(__POSIX_C_SOURCE) && !defined(__LP64__)
 157 struct __shmid_ds_old {
 158         struct __ipc_perm_old shm_perm; /* [XSI] Operation permission value */
 159         size_t          shm_segsz;      /* [XSI] Size of segment in bytes */
 160         pid_t           shm_lpid;       /* [XSI] PID of last shared memory op */
 161         pid_t           shm_cpid;       /* [XSI] PID of creator */
 162         short           shm_nattch;     /* [XSI] Number of current attaches */
 163         time_t          shm_atime;      /* [XSI] Time of last shmat() */
 164         time_t          shm_dtime;      /* [XSI] Time of last shmdt() */
 165         time_t          shm_ctime;      /* [XSI] Time of last shmctl() change */
 166         void            *shm_internal;  /* reserved for kernel use */
 167 };
 168 #endif  /* !_POSIX_C_SOURCE */
 169
 170 #ifndef KERNEL
 171
 172 __BEGIN_DECLS
 173 #ifndef _POSIX_C_SOURCE
 174 int     shmsys(int, ...);
 175 #endif /* !_POSIX_C_SOURCE */
 176 void    *shmat (int, const void *, int);
 177 int     shmctl(int, int, struct shmid_ds *) __DARWIN_ALIAS(shmctl);
 178 int     shmdt(const void *);
 179 int     shmget(key_t, size_t, int);
 180 __END_DECLS
 181
 182 #endif /* !KERNEL */
 183
 184 #endif /* !_SYS_SHM_H_ */