xref: /xnu-8792.81.2/bsd/sys/shm.h (revision 19c3b8c28c31cb8130e034cfb5df6bf9ba342d90)
1 /*
2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*	$NetBSD: shm.h,v 1.15 1994/06/29 06:45:17 cgd Exp $	*/
29 
30 /*
31  * Copyright (c) 1994 Adam Glass
32  * All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  * 3. All advertising materials mentioning features or use of this software
43  *    must display the following acknowledgement:
44  *      This product includes software developed by Adam Glass.
45  * 4. The name of the author may not be used to endorse or promote products
46  *    derived from this software without specific prior written permission
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
49  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
50  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
51  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
52  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
53  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
54  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
55  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
56  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
57  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
58  */
59 
60 /*
61  * As defined+described in "X/Open System Interfaces and Headers"
62  *                         Issue 4, p. XXX
63  */
64 
65 #ifndef _SYS_SHM_H_
66 #define _SYS_SHM_H_
67 
68 #include <sys/cdefs.h>
69 #include <sys/_types.h>
70 
71 /*
72  * [XSI]	All of the symbols from <sys/ipc.h> SHALL be defined
73  *		when this header is included
74  */
75 #include <sys/ipc.h>
76 
77 /*
78  * [XSI] The pid_t, time_t, key_t, and size_t types shall be defined as
79  * described in <sys/types.h>.
80  *
81  * NOTE:	The definition of the key_t type is implicit from the
82  *		inclusion of <sys/ipc.h>
83  */
84 #include <sys/_types/_pid_t.h>
85 #include <sys/_types/_time_t.h>
86 #include <sys/_types/_size_t.h>
87 
88 /*
89  * [XSI] The unsigned integer type used for the number of current attaches
90  * that MUST be able to store values at least as large as a type unsigned
91  * short.
92  */
93 typedef unsigned short  shmatt_t;
94 
95 
96 /*
97  * Possible flag values which may be OR'ed into the third argument to
98  * shmat()
99  */
100 #define SHM_RDONLY      010000  /* [XSI] Attach read-only (else read-write) */
101 #define SHM_RND         020000  /* [XSI] Round attach address to SHMLBA */
102 
103 /*
104  * This value is symbolic, and generally not expected to be sed by user
105  * programs directly, although such ise is permitted by the standard.  Its
106  * value in our implementation is equal to the number of bytes per page.
107  *
108  * NOTE:	We DO NOT obtain this value from the appropriate system
109  *		headers at this time, to avoid the resulting namespace
110  *		pollution, which is why we discourages its use.
111  */
112 #if __arm64__
113 #define SHMLBA      (16*1024)   /* [XSI] Segment low boundary address multiple*/
114 #else /* __arm64__ */
115 #define SHMLBA      4096        /* [XSI] Segment low boundary address multiple*/
116 #endif /* __arm64__ */
117 
118 /* "official" access mode definitions; somewhat braindead since you have
119  *  to specify (SHM_* >> 3) for group and (SHM_* >> 6) for world permissions */
120 #define SHM_R       (IPC_R)
121 #define SHM_W       (IPC_W)
122 
123 #pragma pack(4)
124 
125 /*
126  * Technically, we should force all code references to the new structure
127  * definition, not in just the standards conformance case, and leave the
128  * legacy interface there for binary compatibility only.  Currently, we
129  * are only forcing this for programs requesting standards conformance.
130  */
131 #if __DARWIN_UNIX03 || defined(KERNEL)
132 /*
133  * Structure used internally.
134  *
135  * This structure is exposed because standards dictate that it is used as
136  * the third argment to shmctl().
137  *
138  * NOTE:	The field shm_internal is not meaningful in user space,
139  *		and must not be used there.
140  */
141 #if (defined(_POSIX_C_SOURCE) && !defined(_DARWIN_C_SOURCE))
142 struct shmid_ds
143 #else
144 #define shmid_ds        __shmid_ds_new
145 struct __shmid_ds_new
146 #endif
147 {
148 	struct __ipc_perm_new shm_perm; /* [XSI] Operation permission value */
149 	size_t          shm_segsz;      /* [XSI] Size of segment in bytes */
150 	pid_t           shm_lpid;       /* [XSI] PID of last shared memory op */
151 	pid_t           shm_cpid;       /* [XSI] PID of creator */
152 	shmatt_t        shm_nattch;     /* [XSI] Number of current attaches */
153 	time_t          shm_atime;      /* [XSI] Time of last shmat() */
154 	time_t          shm_dtime;      /* [XSI] Time of last shmdt() */
155 	time_t          shm_ctime;      /* [XSI] Time of last shmctl() change */
156 	void            *shm_internal;  /* reserved for kernel use */
157 };
158 #else   /* !__DARWIN_UNIX03 */
159 #define shmid_ds        __shmid_ds_old
160 #endif  /* !__DARWIN_UNIX03 */
161 
162 #if !__DARWIN_UNIX03
163 struct __shmid_ds_old {
164 	struct __ipc_perm_old shm_perm; /* [XSI] Operation permission value */
165 	size_t          shm_segsz;      /* [XSI] Size of segment in bytes */
166 	pid_t           shm_lpid;       /* [XSI] PID of last shared memory op */
167 	pid_t           shm_cpid;       /* [XSI] PID of creator */
168 	shmatt_t        shm_nattch;     /* [XSI] Number of current attaches */
169 	time_t          shm_atime;      /* [XSI] Time of last shmat() */
170 	time_t          shm_dtime;      /* [XSI] Time of last shmdt() */
171 	time_t          shm_ctime;      /* [XSI] Time of last shmctl() change */
172 	void            *shm_internal;  /* reserved for kernel use */
173 };
174 #endif  /* !__DARWIN_UNIX03 */
175 
176 #pragma pack()
177 
178 #ifndef KERNEL
179 
180 __BEGIN_DECLS
181 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
182 int     shmsys(int, ...);
183 #endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
184 void    *shmat(int, const void *, int);
185 int     shmctl(int, int, struct shmid_ds *) __DARWIN_ALIAS(shmctl);
186 int     shmdt(const void *);
187 int     shmget(key_t, size_t, int);
188 __END_DECLS
189 
190 #endif /* !KERNEL */
191 
192 #endif /* !_SYS_SHM_H_ */
193