← Back to branch summary

~galfy/helenos/bird-port-mainline

« back to all changes in this revision

Viewing changes to kernel/generic/include/synch/spinlock.h

  • Committer: Martin Decky
  • Date: 2009-08-04 11:19:19 UTC
  • Revision ID: martin@uranus.dsrg.hide.ms.mff.cuni.cz-20090804111919-evyclddlr3v5lhmp
Initial import

Show diffs side-by-side

added added

removed removed

Lines of Context:
kernel/generic/include/synch/spinlock.h
 
1
/*
 
2
 * Copyright (c) 2001-2004 Jakub Jermar
 
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
 *
 
9
 * - Redistributions of source code must retain the above copyright
 
10
 *   notice, this list of conditions and the following disclaimer.
 
11
 * - 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
 * - The name of the author may not be used to endorse or promote products
 
15
 *   derived from this software without specific prior written permission.
 
16
 *
 
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
27
 */
 
28
 
 
29
/** @addtogroup sync
 
30
 * @{
 
31
 */
 
32
/** @file
 
33
 */
 
34
 
 
35
#ifndef KERN_SPINLOCK_H_
 
36
#define KERN_SPINLOCK_H_
 
37
 
 
38
#include <arch/types.h>
 
39
#include <arch/barrier.h>
 
40
#include <preemption.h>
 
41
#include <atomic.h>
 
42
#include <debug.h>
 
43
 
 
44
#ifdef CONFIG_SMP
 
45
typedef struct {
 
46
#ifdef CONFIG_DEBUG_SPINLOCK
 
47
        char *name;
 
48
#endif
 
49
        atomic_t val;
 
50
} spinlock_t;
 
51
 
 
52
/*
 
53
 * SPINLOCK_DECLARE is to be used for dynamically allocated spinlocks,
 
54
 * where the lock gets initialized in run time.
 
55
 */
 
56
#define SPINLOCK_DECLARE(slname)        spinlock_t slname
 
57
#define SPINLOCK_EXTERN(slname)         extern spinlock_t slname
 
58
 
 
59
/*
 
60
 * SPINLOCK_INITIALIZE is to be used for statically allocated spinlocks.
 
61
 * It declares and initializes the lock.
 
62
 */
 
63
#ifdef CONFIG_DEBUG_SPINLOCK
 
64
#define SPINLOCK_INITIALIZE(slname)     \
 
65
        spinlock_t slname = {           \
 
66
                .name = #slname,        \
 
67
                .val = { 0 }            \
 
68
        }
 
69
#else
 
70
#define SPINLOCK_INITIALIZE(slname)     \
 
71
        spinlock_t slname = {           \
 
72
                .val = { 0 }            \
 
73
        }
 
74
#endif
 
75
 
 
76
extern void spinlock_initialize(spinlock_t *sl, char *name);
 
77
extern int spinlock_trylock(spinlock_t *sl);
 
78
extern void spinlock_lock_debug(spinlock_t *sl);
 
79
 
 
80
#ifdef CONFIG_DEBUG_SPINLOCK
 
81
#  define spinlock_lock(x) spinlock_lock_debug(x)
 
82
#else
 
83
#  define spinlock_lock(x) atomic_lock_arch(&(x)->val)
 
84
#endif
 
85
 
 
86
/** Unlock spinlock
 
87
 *
 
88
 * Unlock spinlock.
 
89
 *
 
90
 * @param sl Pointer to spinlock_t structure.
 
91
 */
 
92
static inline void spinlock_unlock(spinlock_t *sl)
 
93
{
 
94
        ASSERT(atomic_get(&sl->val) != 0);
 
95
 
 
96
        /*
 
97
         * Prevent critical section code from bleeding out this way down.
 
98
         */
 
99
        CS_LEAVE_BARRIER();
 
100
        
 
101
        atomic_set(&sl->val, 0);
 
102
        preemption_enable();
 
103
}
 
104
 
 
105
#ifdef CONFIG_DEBUG_SPINLOCK
 
106
 
 
107
extern int printf(const char *, ...);
 
108
 
 
109
#define DEADLOCK_THRESHOLD              100000000
 
110
#define DEADLOCK_PROBE_INIT(pname)      size_t pname = 0
 
111
#define DEADLOCK_PROBE(pname, value)                                    \
 
112
        if ((pname)++ > (value)) {                                      \
 
113
                (pname) = 0;                                            \
 
114
                printf("Deadlock probe %s: exceeded threshold %u\n",    \
 
115
                    "cpu%u: function=%s, line=%u\n",                    \
 
116
                    #pname, (value), CPU->id, __func__, __LINE__);      \
 
117
        }
 
118
#else
 
119
#define DEADLOCK_PROBE_INIT(pname)
 
120
#define DEADLOCK_PROBE(pname, value)
 
121
#endif
 
122
 
 
123
#else
 
124
 
 
125
/* On UP systems, spinlocks are effectively left out. */
 
126
#define SPINLOCK_DECLARE(name)
 
127
#define SPINLOCK_EXTERN(name)
 
128
#define SPINLOCK_INITIALIZE(name)
 
129
 
 
130
#define spinlock_initialize(x, name)
 
131
#define spinlock_lock(x)                preemption_disable()
 
132
#define spinlock_trylock(x)             (preemption_disable(), 1)
 
133
#define spinlock_unlock(x)              preemption_enable()
 
134
 
 
135
#define DEADLOCK_PROBE_INIT(pname)
 
136
#define DEADLOCK_PROBE(pname, value)
 
137
 
 
138
#endif
 
139
 
 
140
#endif
 
141
 
 
142
/** @}
 
143
 */