xref: /titanic_50/usr/src/lib/libfakekernel/common/mutex.c (revision b819cea2f73f98c5662230cc9affc8cc84f77fcf)
1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
14  */
15 
16 /*
17  * mutex(9f)
18  */
19 
20 /* This is the API we're emulating */
21 #include <sys/mutex.h>
22 
23 #include <sys/errno.h>
24 #include <sys/debug.h>
25 #include <sys/thread.h>
26 
27 int	_lwp_mutex_lock(lwp_mutex_t *);
28 int	_lwp_mutex_unlock(lwp_mutex_t *);
29 int	_lwp_mutex_trylock(lwp_mutex_t *);
30 
31 extern clock_t ddi_get_lbolt(void);
32 extern void clock2ts(clock_t, timespec_t *);
33 
34 static const lwp_mutex_t default_mutex =
35 	{{0, 0, 0, {USYNC_THREAD}, _MUTEX_MAGIC},
36 	{{{0, 0, 0, 0, 0, 0, 0, 0}}}, 0};
37 
38 /* ARGSUSED */
39 void
kmutex_init(kmutex_t * mp,char * name,kmutex_type_t typ,void * arg)40 kmutex_init(kmutex_t *mp, char *name, kmutex_type_t typ, void *arg)
41 {
42 	mp->m_lock = default_mutex;
43 	mp->m_owner = _KTHREAD_INVALID;
44 }
45 
46 /* ARGSUSED */
47 void
kmutex_destroy(kmutex_t * mp)48 kmutex_destroy(kmutex_t *mp)
49 {
50 	mp->m_owner = _KTHREAD_INVALID;
51 }
52 
53 void
mutex_enter(kmutex_t * mp)54 mutex_enter(kmutex_t *mp)
55 {
56 	VERIFY(0 == _lwp_mutex_lock(&mp->m_lock));
57 	mp->m_owner = _curthread();
58 }
59 
60 int
mutex_tryenter(kmutex_t * mp)61 mutex_tryenter(kmutex_t *mp)
62 {
63 	int rc;
64 
65 	rc = _lwp_mutex_trylock(&mp->m_lock);
66 	if (rc == 0) {
67 		mp->m_owner = _curthread();
68 		return (1);
69 	}
70 	return (0);
71 }
72 
73 void
mutex_exit(kmutex_t * mp)74 mutex_exit(kmutex_t *mp)
75 {
76 	ASSERT(mp->m_owner == _curthread());
77 	mp->m_owner = _KTHREAD_INVALID;
78 	(void) _lwp_mutex_unlock(&mp->m_lock);
79 }
80 
81 /*
82  * Returns the kthread_t * of the owner.
83  */
84 void *
mutex_owner(const kmutex_t * mp)85 mutex_owner(const kmutex_t *mp)
86 {
87 	return (mp->m_owner);
88 }
89 
90 int
mutex_owned(const kmutex_t * mp)91 mutex_owned(const kmutex_t *mp)
92 {
93 	void *t = _curthread();
94 	return (t == mp->m_owner);
95 }
96