xref: /illumos-gate/usr/src/lib/libfakekernel/common/sys/mutex.h (revision b819cea2f73f98c5662230cc9affc8cc84f77fcf)
1*b819cea2SGordon Ross /*
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8*b819cea2SGordon Ross  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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13*b819cea2SGordon Ross  * When distributing Covered Code, include this CDDL HEADER in each
14*b819cea2SGordon Ross  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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18*b819cea2SGordon Ross  *
19*b819cea2SGordon Ross  * CDDL HEADER END
20*b819cea2SGordon Ross  */
21*b819cea2SGordon Ross /*
22*b819cea2SGordon Ross  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
23*b819cea2SGordon Ross  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
24*b819cea2SGordon Ross  */
25*b819cea2SGordon Ross 
26*b819cea2SGordon Ross #ifndef _SYS_MUTEX_H
27*b819cea2SGordon Ross #define	_SYS_MUTEX_H
28*b819cea2SGordon Ross 
29*b819cea2SGordon Ross #include <sys/synch.h>	/* lwp_mutex_t */
30*b819cea2SGordon Ross 
31*b819cea2SGordon Ross #ifdef	__cplusplus
32*b819cea2SGordon Ross extern "C" {
33*b819cea2SGordon Ross #endif
34*b819cea2SGordon Ross 
35*b819cea2SGordon Ross /*
36*b819cea2SGordon Ross  * Public interface to mutual exclusion locks.  See mutex(9F) for details.
37*b819cea2SGordon Ross  *
38*b819cea2SGordon Ross  * The basic mutex type is MUTEX_ADAPTIVE, which is expected to be used
39*b819cea2SGordon Ross  * in almost all of the kernel.  MUTEX_SPIN provides interrupt blocking
40*b819cea2SGordon Ross  * and must be used in interrupt handlers above LOCK_LEVEL.  The iblock
41*b819cea2SGordon Ross  * cookie argument to mutex_init() encodes the interrupt level to block.
42*b819cea2SGordon Ross  * The iblock cookie must be NULL for adaptive locks.
43*b819cea2SGordon Ross  *
44*b819cea2SGordon Ross  * MUTEX_DEFAULT is the type usually specified (except in drivers) to
45*b819cea2SGordon Ross  * mutex_init().  It is identical to MUTEX_ADAPTIVE.
46*b819cea2SGordon Ross  *
47*b819cea2SGordon Ross  * MUTEX_DRIVER is always used by drivers.  mutex_init() converts this to
48*b819cea2SGordon Ross  * either MUTEX_ADAPTIVE or MUTEX_SPIN depending on the iblock cookie.
49*b819cea2SGordon Ross  *
50*b819cea2SGordon Ross  * Mutex statistics can be gathered on the fly, without rebooting or
51*b819cea2SGordon Ross  * recompiling the kernel, via the lockstat driver (lockstat(7D)).
52*b819cea2SGordon Ross  */
53*b819cea2SGordon Ross typedef enum {
54*b819cea2SGordon Ross 	MUTEX_ADAPTIVE = 0,	/* spin if owner is running, otherwise block */
55*b819cea2SGordon Ross 	MUTEX_SPIN = 1,		/* block interrupts and spin */
56*b819cea2SGordon Ross 	MUTEX_DRIVER = 4,	/* driver (DDI) mutex */
57*b819cea2SGordon Ross 	MUTEX_DEFAULT = 6	/* kernel default mutex */
58*b819cea2SGordon Ross } kmutex_type_t;
59*b819cea2SGordon Ross 
60*b819cea2SGordon Ross struct _kmutex {
61*b819cea2SGordon Ross 	lwp_mutex_t m_lock;
62*b819cea2SGordon Ross 	void *m_owner;
63*b819cea2SGordon Ross };
64*b819cea2SGordon Ross typedef struct _kmutex kmutex_t;
65*b819cea2SGordon Ross 
66*b819cea2SGordon Ross #if defined(_KERNEL) || defined(_FAKE_KERNEL)
67*b819cea2SGordon Ross /* See the real sys/mutex.h */
68*b819cea2SGordon Ross typedef struct pad_mutex {
69*b819cea2SGordon Ross 	kmutex_t	pad_mutex;
70*b819cea2SGordon Ross #ifdef _LP64
71*b819cea2SGordon Ross 	char		pad_pad[64 - sizeof (kmutex_t)];
72*b819cea2SGordon Ross #endif
73*b819cea2SGordon Ross } pad_mutex_t;
74*b819cea2SGordon Ross #endif	/* _KERNEL */
75*b819cea2SGordon Ross 
76*b819cea2SGordon Ross #define	MUTEX_HELD(x)		(mutex_owned(x))
77*b819cea2SGordon Ross #define	MUTEX_NOT_HELD(x)	(!mutex_owned(x) || panicstr)
78*b819cea2SGordon Ross 
79*b819cea2SGordon Ross /*
80*b819cea2SGordon Ross  * We're simulating the kernel mutex API here, and the
81*b819cea2SGordon Ross  * user-level has a different signature, so rename.
82*b819cea2SGordon Ross  */
83*b819cea2SGordon Ross #define	mutex_init	kmutex_init
84*b819cea2SGordon Ross #define	mutex_destroy	kmutex_destroy
85*b819cea2SGordon Ross 
86*b819cea2SGordon Ross extern	void	kmutex_init(kmutex_t *, char *, kmutex_type_t, void *);
87*b819cea2SGordon Ross extern	void	kmutex_destroy(kmutex_t *);
88*b819cea2SGordon Ross 
89*b819cea2SGordon Ross extern	void	mutex_enter(kmutex_t *);
90*b819cea2SGordon Ross extern	int	mutex_tryenter(kmutex_t *);
91*b819cea2SGordon Ross extern	void	mutex_exit(kmutex_t *);
92*b819cea2SGordon Ross extern	int	mutex_owned(const kmutex_t *);
93*b819cea2SGordon Ross 
94*b819cea2SGordon Ross extern	void *mutex_owner(const kmutex_t *);
95*b819cea2SGordon Ross 
96*b819cea2SGordon Ross #ifdef	__cplusplus
97*b819cea2SGordon Ross }
98*b819cea2SGordon Ross #endif
99*b819cea2SGordon Ross 
100*b819cea2SGordon Ross #endif	/* _SYS_MUTEX_H */
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