umtx.h revision 231989 
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 231989 2012-02-22 03:22:49Z davidxu $
27 *
28 */
29
30#ifndef _SYS_UMTX_H_
31#define	_SYS_UMTX_H_
32
33#include <sys/_umtx.h>
34#include <sys/limits.h>
35
36#define	UMTX_UNOWNED		0x0
37#define	UMTX_CONTESTED		LONG_MIN
38
39#define USYNC_PROCESS_SHARED	0x0001	/* Process shared sync objs */
40
41#define	UMUTEX_UNOWNED		0x0
42#define	UMUTEX_CONTESTED	0x80000000U
43
44#define	UMUTEX_ERROR_CHECK	0x0002	/* Error-checking mutex */
45#define	UMUTEX_PRIO_INHERIT	0x0004	/* Priority inherited mutex */
46#define	UMUTEX_PRIO_PROTECT	0x0008	/* Priority protect mutex */
47
48/* urwlock flags */
49#define URWLOCK_PREFER_READER	0x0002
50
51#define URWLOCK_WRITE_OWNER	0x80000000U
52#define URWLOCK_WRITE_WAITERS	0x40000000U
53#define URWLOCK_READ_WAITERS	0x20000000U
54#define URWLOCK_MAX_READERS	0x1fffffffU
55#define URWLOCK_READER_COUNT(c)	((c) & URWLOCK_MAX_READERS)
56
57/* _usem flags */
58#define SEM_NAMED	0x0002
59
60/* op code for _umtx_op */
61#define	UMTX_OP_LOCK		0
62#define	UMTX_OP_UNLOCK		1
63#define	UMTX_OP_WAIT		2
64#define	UMTX_OP_WAKE		3
65#define	UMTX_OP_MUTEX_TRYLOCK	4
66#define	UMTX_OP_MUTEX_LOCK	5
67#define	UMTX_OP_MUTEX_UNLOCK	6
68#define	UMTX_OP_SET_CEILING	7
69#define	UMTX_OP_CV_WAIT		8
70#define	UMTX_OP_CV_SIGNAL	9
71#define	UMTX_OP_CV_BROADCAST	10
72#define	UMTX_OP_WAIT_UINT	11
73#define	UMTX_OP_RW_RDLOCK	12
74#define	UMTX_OP_RW_WRLOCK	13
75#define	UMTX_OP_RW_UNLOCK	14
76#define	UMTX_OP_WAIT_UINT_PRIVATE	15
77#define	UMTX_OP_WAKE_PRIVATE	16
78#define	UMTX_OP_MUTEX_WAIT	17
79#define	UMTX_OP_MUTEX_WAKE	18
80#define	UMTX_OP_SEM_WAIT	19
81#define	UMTX_OP_SEM_WAKE	20
82#define	UMTX_OP_NWAKE_PRIVATE   21
83#define	UMTX_OP_MAX		22
84
85/* Flags for UMTX_OP_CV_WAIT */
86#define	CVWAIT_CHECK_UNPARKING	0x01
87#define	CVWAIT_ABSTIME		0x02
88#define	CVWAIT_CLOCKID		0x04
89
90#define	UMTX_WAIT_ABSTIME	0x01
91
92#define	UMTX_CHECK_UNPARKING	CVWAIT_CHECK_UNPARKING
93
94#ifndef _KERNEL
95
96int _umtx_op(void *obj, int op, u_long val, void *uaddr, void *uaddr2);
97
98/*
99 * Old (deprecated) userland mutex system calls.
100 */
101int _umtx_lock(struct umtx *mtx);
102int _umtx_unlock(struct umtx *mtx);
103
104/*
105 * Standard api.  Try uncontested acquire/release and asks the
106 * kernel to resolve failures.
107 */
108static __inline void
109umtx_init(struct umtx *umtx)
110{
111	umtx->u_owner = UMTX_UNOWNED;
112}
113
114static __inline u_long
115umtx_owner(struct umtx *umtx)
116{
117	return (umtx->u_owner & ~LONG_MIN);
118}
119
120static __inline int
121umtx_lock(struct umtx *umtx, u_long id)
122{
123	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
124		if (_umtx_lock(umtx) == -1)
125			return (errno);
126	return (0);
127}
128
129static __inline int
130umtx_trylock(struct umtx *umtx, u_long id)
131{
132	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
133		return (EBUSY);
134	return (0);
135}
136
137static __inline int
138umtx_timedlock(struct umtx *umtx, u_long id, const struct timespec *timeout)
139{
140	if (atomic_cmpset_acq_long(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
141		if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0,
142		    __DECONST(void *, timeout)) == -1)
143			return (errno);
144	return (0);
145}
146
147static __inline int
148umtx_unlock(struct umtx *umtx, u_long id)
149{
150	if (atomic_cmpset_rel_long(&umtx->u_owner, id, UMTX_UNOWNED) == 0)
151		if (_umtx_unlock(umtx) == -1)
152			return (errno);
153	return (0);
154}
155
156static __inline int
157umtx_wait(u_long *p, long val, const struct timespec *timeout)
158{
159	if (_umtx_op(p, UMTX_OP_WAIT, val, 0,
160	    __DECONST(void *, timeout)) == -1)
161		return (errno);
162	return (0);
163}
164
165/* Wake threads waiting on a user address. */
166static __inline int
167umtx_wake(u_long *p, int nr_wakeup)
168{
169	if (_umtx_op(p, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
170		return (errno);
171	return (0);
172}
173
174#else
175
176/*
177 * The umtx_key structure is used by both the Linux futex code and the
178 * umtx implementation to map userland addresses to unique keys.
179 */
180
181enum {
182	TYPE_SIMPLE_WAIT,
183	TYPE_CV,
184	TYPE_SEM,
185	TYPE_SIMPLE_LOCK,
186	TYPE_NORMAL_UMUTEX,
187	TYPE_PI_UMUTEX,
188	TYPE_PP_UMUTEX,
189	TYPE_RWLOCK,
190	TYPE_FUTEX
191};
192
193/* Key to represent a unique userland synchronous object */
194struct umtx_key {
195	int	hash;
196	int	type;
197	int	shared;
198	union {
199		struct {
200			struct vm_object *object;
201			uintptr_t	offset;
202		} shared;
203		struct {
204			struct vmspace	*vs;
205			uintptr_t	addr;
206		} private;
207		struct {
208			void		*a;
209			uintptr_t	b;
210		} both;
211	} info;
212};
213
214#define THREAD_SHARE		0
215#define PROCESS_SHARE		1
216#define AUTO_SHARE		2
217
218struct thread;
219
220static inline int
221umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2)
222{
223	return (k1->type == k2->type &&
224		k1->info.both.a == k2->info.both.a &&
225	        k1->info.both.b == k2->info.both.b);
226}
227
228int umtx_copyin_timeout(const void *, struct timespec *);
229int umtx_key_get(void *, int, int, struct umtx_key *);
230void umtx_key_release(struct umtx_key *);
231struct umtx_q *umtxq_alloc(void);
232void umtxq_free(struct umtx_q *);
233int kern_umtx_wake(struct thread *, void *, int, int);
234void umtx_pi_adjust(struct thread *, u_char);
235void umtx_thread_init(struct thread *);
236void umtx_thread_fini(struct thread *);
237void umtx_thread_alloc(struct thread *);
238void umtx_thread_exit(struct thread *);
239#endif /* !_KERNEL */
240#endif /* !_SYS_UMTX_H_ */
241