umtx.h revision 177848 
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 177848 2008-04-02 04:08:37Z 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
69struct urwlock {
70	volatile int32_t	rw_state;
71	uint32_t		rw_flags;
72	uint32_t		rw_blocked_readers;
73	uint32_t		rw_blocked_writers;
74	uint32_t		rw_spare[4];
75};
76
77/* urwlock flags */
78#define URWLOCK_PREFER_READER	0x0002
79
80#define URWLOCK_WRITE_OWNER	0x80000000U
81#define URWLOCK_WRITE_WAITERS	0x40000000U
82#define URWLOCK_READ_WAITERS	0x20000000U
83#define URWLOCK_MAX_READERS	0x1fffffffU
84#define URWLOCK_READER_COUNT(c)	((c) & URWLOCK_MAX_READERS)
85
86/* op code for _umtx_op */
87#define	UMTX_OP_LOCK		0
88#define	UMTX_OP_UNLOCK		1
89#define	UMTX_OP_WAIT		2
90#define	UMTX_OP_WAKE		3
91#define	UMTX_OP_MUTEX_TRYLOCK	4
92#define	UMTX_OP_MUTEX_LOCK	5
93#define	UMTX_OP_MUTEX_UNLOCK	6
94#define	UMTX_OP_SET_CEILING	7
95#define	UMTX_OP_CV_WAIT		8
96#define	UMTX_OP_CV_SIGNAL	9
97#define	UMTX_OP_CV_BROADCAST	10
98#define	UMTX_OP_WAIT_UINT	11
99#define	UMTX_OP_RW_RDLOCK	12
100#define	UMTX_OP_RW_WRLOCK	13
101#define	UMTX_OP_RW_UNLOCK	14
102#define	UMTX_OP_MAX		15
103
104/* flags for UMTX_OP_CV_WAIT */
105#define UMTX_CHECK_UNPARKING	0x01
106
107#ifndef _KERNEL
108
109int _umtx_op(void *obj, int op, u_long val, void *uaddr, void *uaddr2);
110
111/*
112 * Old (deprecated) userland mutex system calls.
113 */
114int _umtx_lock(struct umtx *mtx);
115int _umtx_unlock(struct umtx *mtx);
116
117/*
118 * Standard api.  Try uncontested acquire/release and asks the
119 * kernel to resolve failures.
120 */
121static __inline void
122umtx_init(struct umtx *umtx)
123{
124	umtx->u_owner = UMTX_UNOWNED;
125}
126
127static __inline u_long
128umtx_owner(struct umtx *umtx)
129{
130	return (umtx->u_owner & ~LONG_MIN);
131}
132
133static __inline int
134umtx_lock(struct umtx *umtx, u_long id)
135{
136	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
137		if (_umtx_lock(umtx) == -1)
138			return (errno);
139	return (0);
140}
141
142static __inline int
143umtx_trylock(struct umtx *umtx, u_long id)
144{
145	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
146		return (EBUSY);
147	return (0);
148}
149
150static __inline int
151umtx_timedlock(struct umtx *umtx, u_long id, const struct timespec *timeout)
152{
153	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
154		if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0,
155		    __DECONST(void *, timeout)) == -1)
156			return (errno);
157	return (0);
158}
159
160static __inline int
161umtx_unlock(struct umtx *umtx, u_long id)
162{
163	if (atomic_cmpset_rel_long(&umtx->u_owner, id, UMTX_UNOWNED) == 0)
164		if (_umtx_unlock(umtx) == -1)
165			return (errno);
166	return (0);
167}
168
169static __inline int
170umtx_wait(u_long *p, long val, const struct timespec *timeout)
171{
172	if (_umtx_op(p, UMTX_OP_WAIT, val, 0,
173	    __DECONST(void *, timeout)) == -1)
174		return (errno);
175	return (0);
176}
177
178/* Wake threads waiting on a user address. */
179static __inline int
180umtx_wake(u_long *p, int nr_wakeup)
181{
182	if (_umtx_op(p, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
183		return (errno);
184	return (0);
185}
186
187#else
188
189struct thread;
190
191struct umtx_q *umtxq_alloc(void);
192void umtxq_free(struct umtx_q *);
193int kern_umtx_wake(struct thread *td, void *uaddr, int n_wake);
194void umtx_pi_adjust(struct thread *td, u_char oldpri);
195void umtx_thread_init(struct thread *td);
196void umtx_thread_fini(struct thread *td);
197void umtx_thread_alloc(struct thread *td);
198void umtx_thread_exit(struct thread *td);
199#endif /* !_KERNEL */
200#endif /* !_SYS_UMTX_H_ */
201