umtx.h revision 163449 
1/*-
2 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/sys/umtx.h 163449 2006-10-17 02:24:47Z davidxu $
27 *
28 */
29
30#ifndef _SYS_UMTX_H_
31#define	_SYS_UMTX_H_
32
33#include <sys/_types.h>
34#include <sys/limits.h>
35
36/*
37 * See pthread_*
38 */
39
40#define	UMTX_UNOWNED	0x0
41#define	UMTX_CONTESTED	LONG_MIN
42
43struct umtx {
44	volatile u_long	u_owner;	/* Owner of the mutex. */
45};
46
47#define USYNC_PROCESS_SHARED	0x0001	/* Process shared sync objs */
48
49#define	UMUTEX_UNOWNED		0x0
50#define	UMUTEX_CONTESTED	0x80000000
51
52#define UMUTEX_ERROR_CHECK	0x0002	/* Error-checking mutex */
53#define UMUTEX_PRIO_INHERIT	0x0004	/* Priority inherited mutex */
54#define UMUTEX_PRIO_PROTECT	0x0008	/* Priority protect mutex */
55struct umutex {
56	volatile __lwpid_t	m_owner;	/* Owner of the mutex */
57	uint32_t	m_flags;	/* Flags of the mutex */
58	uint32_t	m_ceilings[2];	/* Priority protect ceiling */
59	uint32_t	m_spare[4];	/* Spare space */
60};
61
62/* op code for _umtx_op */
63#define UMTX_OP_LOCK		0
64#define UMTX_OP_UNLOCK		1
65#define UMTX_OP_WAIT		2
66#define UMTX_OP_WAKE		3
67#define UMTX_OP_MUTEX_TRYLOCK	4
68#define UMTX_OP_MUTEX_LOCK	5
69#define UMTX_OP_MUTEX_UNLOCK	6
70#define UMTX_OP_SET_CEILING	7
71#define UMTX_OP_MAX		8
72
73#ifndef _KERNEL
74
75int _umtx_op(void *obj, int op, u_long val, void *uaddr, void *uaddr2);
76
77/*
78 * Old (deprecated) userland mutex system calls.
79 */
80int _umtx_lock(struct umtx *mtx);
81int _umtx_unlock(struct umtx *mtx);
82
83/*
84 * Standard api.  Try uncontested acquire/release and asks the
85 * kernel to resolve failures.
86 */
87static __inline void
88umtx_init(struct umtx *umtx)
89{
90	umtx->u_owner = UMTX_UNOWNED;
91}
92
93static __inline u_long
94umtx_owner(struct umtx *umtx)
95{
96	return (umtx->u_owner & ~LONG_MIN);
97}
98
99static __inline int
100umtx_lock(struct umtx *umtx, u_long id)
101{
102	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
103		if (_umtx_lock(umtx) == -1)
104			return (errno);
105	return (0);
106}
107
108static __inline int
109umtx_trylock(struct umtx *umtx, u_long id)
110{
111	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
112		return (EBUSY);
113	return (0);
114}
115
116static __inline int
117umtx_timedlock(struct umtx *umtx, u_long id, const struct timespec *timeout)
118{
119	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
120		if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0,
121		    __DECONST(void *, timeout)) == -1)
122			return (errno);
123	return (0);
124}
125
126static __inline int
127umtx_unlock(struct umtx *umtx, u_long id)
128{
129	if (atomic_cmpset_rel_long(&umtx->u_owner, id, UMTX_UNOWNED) == 0)
130		if (_umtx_unlock(umtx) == -1)
131			return (errno);
132	return (0);
133}
134
135static __inline int
136umtx_wait(u_long *p, long val, const struct timespec *timeout)
137{
138	if (_umtx_op(p, UMTX_OP_WAIT, val, 0,
139	    __DECONST(void *, timeout)) == -1)
140		return (errno);
141	return (0);
142}
143
144/* Wake threads waiting on a user address. */
145static __inline int
146umtx_wake(u_long *p, int nr_wakeup)
147{
148	if (_umtx_op(p, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
149		return (errno);
150	return (0);
151}
152
153#else
154
155struct thread;
156
157struct umtx_q *umtxq_alloc(void);
158void umtxq_free(struct umtx_q *);
159int kern_umtx_wake(struct thread *td, void *uaddr, int n_wake);
160void umtx_pi_adjust(struct thread *td, u_char oldpri);
161void umtx_thread_init(struct thread *td);
162void umtx_thread_fini(struct thread *td);
163void umtx_thread_alloc(struct thread *td);
164void umtx_thread_exit(struct thread *td);
165#endif /* !_KERNEL */
166#endif /* !_SYS_UMTX_H_ */
167