umtx.h revision 170368 
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 170368 2007-06-06 07:35:08Z 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	0x80000000U
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 */
55
56struct umutex {
57	volatile __lwpid_t	m_owner;	/* Owner of the mutex */
58	uint32_t		m_flags;	/* Flags of the mutex */
59	uint32_t		m_ceilings[2];	/* Priority protect ceiling */
60	uint32_t		m_spare[4];
61};
62
63struct ucond {
64	volatile uint32_t	c_has_waiters;	/* Has waiters in kernel */
65	uint32_t		c_flags;	/* Flags of the condition variable */
66	uint32_t		c_spare[2];	/* Spare space */
67};
68
69/* op code for _umtx_op */
70#define	UMTX_OP_LOCK		0
71#define	UMTX_OP_UNLOCK		1
72#define	UMTX_OP_WAIT		2
73#define	UMTX_OP_WAKE		3
74#define	UMTX_OP_MUTEX_TRYLOCK	4
75#define	UMTX_OP_MUTEX_LOCK	5
76#define	UMTX_OP_MUTEX_UNLOCK	6
77#define	UMTX_OP_SET_CEILING	7
78#define	UMTX_OP_CV_WAIT		8
79#define	UMTX_OP_CV_SIGNAL	9
80#define	UMTX_OP_CV_BROADCAST	10
81#define	UMTX_OP_MAX		11
82
83/* flags for UMTX_OP_CV_WAIT */
84#define UMTX_CHECK_UNPARKING	0x01
85
86#ifndef _KERNEL
87
88int _umtx_op(void *obj, int op, u_long val, void *uaddr, void *uaddr2);
89
90/*
91 * Old (deprecated) userland mutex system calls.
92 */
93int _umtx_lock(struct umtx *mtx);
94int _umtx_unlock(struct umtx *mtx);
95
96/*
97 * Standard api.  Try uncontested acquire/release and asks the
98 * kernel to resolve failures.
99 */
100static __inline void
101umtx_init(struct umtx *umtx)
102{
103	umtx->u_owner = UMTX_UNOWNED;
104}
105
106static __inline u_long
107umtx_owner(struct umtx *umtx)
108{
109	return (umtx->u_owner & ~LONG_MIN);
110}
111
112static __inline int
113umtx_lock(struct umtx *umtx, u_long id)
114{
115	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
116		if (_umtx_lock(umtx) == -1)
117			return (errno);
118	return (0);
119}
120
121static __inline int
122umtx_trylock(struct umtx *umtx, u_long id)
123{
124	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
125		return (EBUSY);
126	return (0);
127}
128
129static __inline int
130umtx_timedlock(struct umtx *umtx, u_long id, const struct timespec *timeout)
131{
132	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
133		if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0,
134		    __DECONST(void *, timeout)) == -1)
135			return (errno);
136	return (0);
137}
138
139static __inline int
140umtx_unlock(struct umtx *umtx, u_long id)
141{
142	if (atomic_cmpset_rel_long(&umtx->u_owner, id, UMTX_UNOWNED) == 0)
143		if (_umtx_unlock(umtx) == -1)
144			return (errno);
145	return (0);
146}
147
148static __inline int
149umtx_wait(u_long *p, long val, const struct timespec *timeout)
150{
151	if (_umtx_op(p, UMTX_OP_WAIT, val, 0,
152	    __DECONST(void *, timeout)) == -1)
153		return (errno);
154	return (0);
155}
156
157/* Wake threads waiting on a user address. */
158static __inline int
159umtx_wake(u_long *p, int nr_wakeup)
160{
161	if (_umtx_op(p, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
162		return (errno);
163	return (0);
164}
165
166#else
167
168struct thread;
169
170struct umtx_q *umtxq_alloc(void);
171void umtxq_free(struct umtx_q *);
172int kern_umtx_wake(struct thread *td, void *uaddr, int n_wake);
173void umtx_pi_adjust(struct thread *td, u_char oldpri);
174void umtx_thread_init(struct thread *td);
175void umtx_thread_fini(struct thread *td);
176void umtx_thread_alloc(struct thread *td);
177void umtx_thread_exit(struct thread *td);
178#endif /* !_KERNEL */
179#endif /* !_SYS_UMTX_H_ */
180