xref: /netbsd/sys/sys/ksem.h (revision 1abbb194)
1 /*	$NetBSD: ksem.h,v 1.17 2023/07/11 11:37:29 riastradh Exp $	*/
2 
3 /*
4  * Copyright (c) 2002 Alfred Perlstein <alfred@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef _SYS_KSEM_H_
30 #define _SYS_KSEM_H_
31 
32 #include <sys/cdefs.h>
33 
34 #include <sys/types.h>
35 
36 struct timespec;
37 
38 #ifdef _KERNEL
39 
40 #include <sys/condvar.h>
41 #include <sys/mutex.h>
42 #include <sys/queue.h>
43 
44 #ifndef _KMEMUSER		/* XXX hack for fstat(8) */
45 #include <sys/systm.h>
46 #endif
47 
48 struct lwp;
49 struct proc;
50 
51 #define	KSEM_MAX	128
52 
53 typedef struct ksem {
54 	LIST_ENTRY(ksem)	ks_entry;	/* global list entry */
55 	struct proc *		ks_pshared_proc;/* owner of pshared sem */
56 	intptr_t		ks_pshared_id;	/* global id for pshared sem */
57 	kmutex_t		ks_lock;	/* lock on this ksem */
58 	kcondvar_t		ks_cv;		/* condition variable */
59 	u_int			ks_pshared_fd;	/* fd in owning proc */
60 	u_int			ks_ref;		/* number of references */
61 	u_int			ks_value;	/* current value */
62 	u_int			ks_waiters;	/* number of waiters */
63 	char *			ks_name;	/* name, if named */
64 	size_t			ks_namelen;	/* length of name */
65 	int			ks_flags;	/* for KS_UNLINKED */
66 	mode_t			ks_mode;	/* protection bits */
67 	uid_t			ks_uid;		/* creator uid */
68 	gid_t			ks_gid;		/* creator gid */
69 } ksem_t;
70 
71 int do_ksem_init(struct lwp *, unsigned int, intptr_t *, copyin_t, copyout_t);
72 int do_ksem_open(struct lwp *, const char *, int, mode_t, unsigned int,
73     intptr_t *, copyout_t);
74 int do_ksem_wait(struct lwp *, intptr_t, bool, struct timespec *);
75 
76 extern int	ksem_max;
77 #endif /* _KERNEL */
78 
79 #if defined(_KERNEL) || defined(_LIBC)
80 #define	KSEM_PSHARED		0x50535244U	/* 'PSRD' */
81 
82 #define	KSEM_MARKER_MASK	0xff000001U
83 #define	KSEM_MARKER_MIN		0x01000001U
84 #define	KSEM_PSHARED_MARKER	0x70000001U	/* 'p' << 24 | 1 */
85 #endif /* _KERNEL || _LIBC */
86 
87 #ifdef _LIBC
88 __BEGIN_DECLS
89 int _ksem_close(intptr_t);
90 int _ksem_destroy(intptr_t);
91 int _ksem_getvalue(intptr_t, int *);
92 int _ksem_init(unsigned int, intptr_t *);
93 int _ksem_open(const char *, int, mode_t, unsigned int, intptr_t *);
94 int _ksem_post(intptr_t);
95 int _ksem_timedwait(intptr_t, const struct timespec * __restrict);
96 int _ksem_trywait(intptr_t);
97 int _ksem_unlink(const char *);
98 int _ksem_wait(intptr_t);
99 __END_DECLS
100 #endif /* _LIBC */
101 
102 #endif /* _SYS_KSEM_H_ */
103