xref: /dragonfly/lib/libc/sysvipc/sysvipc_shm.h (revision 548a3528)
1 /*
2  * Copyright (c) 2013 Larisa Grigore <larisagrigore@gmail.com>.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. All advertising materials mentioning features or use of this software
13  *    must display the following acknowledgement:
14  *	This product includes software developed by Adam Glass and Charles
15  *	Hannum.
16  * 4. The names of the authors may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifndef _SYSV_SHM_H_
32 #define _SYSV_SHM_H_
33 
34 #include <sys/ipc.h>
35 
36 /* This flag is used to mark a semaphore group
37  * as removed by another process.
38  */
39 #define SEG_ALREADY_REMOVED	2
40 
41 struct shm_data {
42 	int fd;		/* The file descriptor of the file used as
43 			   shared memory. */
44 	size_t size;
45 	int shmid;
46 	int type;	/* shm, sem, msg or undo;
47 			undo segments are used for semops with UNDO flag set. */
48 	void *internal;
49 	int used;	/* Number of thread that use this segment. */
50 	int removed;	/* The segment was mark for removal by a thread. */
51 	int access;	/* Used only for sems to avoid a segfault when try to
52 			access a semaphore wthout permission. */
53 };
54 
55 int _shmget(key_t, size_t, int, int);
56 void shmchild(void);
57 
58 int sysvipc_shmget (key_t, size_t, int);
59 int sysvipc_shmctl (int, int, struct shmid_ds *);
60 void *sysvipc_shmat  (int, const void *, int);
61 int sysvipc_shmdt  (const void *);
62 
63 struct shm_data *get_shmdata(int, int, int);
64 int set_shmdata_access(int, int);
65 
66 #endif /* !_SYSV_SHM_H_ */
67