1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/*
* Copyright (c) 2015 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#if HAVE_STRUCT__THREAD_QUEUE_QUEUE
#include <sys/lock.h>
#include <rtems/score/assert.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/threadqimpl.h>
#define SEMAPHORE_TQ_OPERATIONS &_Thread_queue_Operations_priority
typedef struct {
Thread_queue_Syslock_queue Queue;
unsigned int count;
} Semaphore_Control;
RTEMS_STATIC_ASSERT(
offsetof( Semaphore_Control, Queue )
== offsetof( struct _Semaphore_Control, _Queue ),
SEMAPHORE_CONTROL_QUEUE
);
RTEMS_STATIC_ASSERT(
offsetof( Semaphore_Control, count )
== offsetof( struct _Semaphore_Control, _count ),
SEMAPHORE_CONTROL_COUNT
);
RTEMS_STATIC_ASSERT(
sizeof( Semaphore_Control ) == sizeof( struct _Semaphore_Control ),
SEMAPHORE_CONTROL_SIZE
);
static Semaphore_Control *_Semaphore_Get(
struct _Semaphore_Control *_sem
)
{
return (Semaphore_Control *) _sem;
}
static Thread_Control *_Semaphore_Queue_acquire_critical(
Semaphore_Control *sem,
Thread_queue_Context *queue_context
)
{
Thread_Control *executing;
executing = _Thread_Executing;
_Thread_queue_Queue_acquire_critical(
&sem->Queue.Queue,
&executing->Potpourri_stats,
&queue_context->Lock_context.Lock_context
);
return executing;
}
static void _Semaphore_Queue_release(
Semaphore_Control *sem,
ISR_Level level,
Thread_queue_Context *queue_context
)
{
_Thread_queue_Queue_release_critical(
&sem->Queue.Queue,
&queue_context->Lock_context.Lock_context
);
_ISR_Local_enable( level );
}
void _Semaphore_Wait( struct _Semaphore_Control *_sem )
{
Semaphore_Control *sem ;
ISR_Level level;
Thread_queue_Context queue_context;
Thread_Control *executing;
unsigned int count;
sem = _Semaphore_Get( _sem );
_Thread_queue_Context_initialize( &queue_context );
_Thread_queue_Context_ISR_disable( &queue_context, level );
executing = _Semaphore_Queue_acquire_critical( sem, &queue_context );
count = sem->count;
if ( __predict_true( count > 0 ) ) {
sem->count = count - 1;
_Semaphore_Queue_release( sem, level, &queue_context );
} else {
_Thread_queue_Context_set_expected_level( &queue_context, 1 );
_Thread_queue_Context_set_no_timeout( &queue_context );
_Thread_queue_Context_set_ISR_level( &queue_context, level );
_Thread_queue_Enqueue_critical(
&sem->Queue.Queue,
SEMAPHORE_TQ_OPERATIONS,
executing,
STATES_WAITING_FOR_SYS_LOCK_SEMAPHORE,
&queue_context
);
}
}
void _Semaphore_Post( struct _Semaphore_Control *_sem )
{
Semaphore_Control *sem;
ISR_Level level;
Thread_queue_Context queue_context;
Thread_queue_Heads *heads;
sem = _Semaphore_Get( _sem );
_Thread_queue_Context_initialize( &queue_context );
_Thread_queue_Context_ISR_disable( &queue_context, level );
_Semaphore_Queue_acquire_critical( sem, &queue_context );
heads = sem->Queue.Queue.heads;
if ( __predict_true( heads == NULL ) ) {
_Assert( sem->count < UINT_MAX );
++sem->count;
_Semaphore_Queue_release( sem, level, &queue_context );
} else {
const Thread_queue_Operations *operations;
Thread_Control *first;
_Thread_queue_Context_set_ISR_level( &queue_context, level );
operations = SEMAPHORE_TQ_OPERATIONS;
first = ( *operations->first )( heads );
_Thread_queue_Extract_critical(
&sem->Queue.Queue,
operations,
first,
&queue_context
);
}
}
#endif /* HAVE_STRUCT__THREAD_QUEUE_QUEUE */
|
