1 | /* |
---|
2 | * Copyright (c) 2015, 2017 embedded brains GmbH. All rights reserved. |
---|
3 | * |
---|
4 | * embedded brains GmbH |
---|
5 | * Dornierstr. 4 |
---|
6 | * 82178 Puchheim |
---|
7 | * Germany |
---|
8 | * <rtems@embedded-brains.de> |
---|
9 | * |
---|
10 | * The license and distribution terms for this file may be |
---|
11 | * found in the file LICENSE in this distribution or at |
---|
12 | * http://www.rtems.org/license/LICENSE. |
---|
13 | */ |
---|
14 | |
---|
15 | #if HAVE_CONFIG_H |
---|
16 | #include "config.h" |
---|
17 | #endif |
---|
18 | |
---|
19 | #include <rtems/score/semaphoreimpl.h> |
---|
20 | #include <rtems/score/statesimpl.h> |
---|
21 | #include <rtems/score/threadimpl.h> |
---|
22 | |
---|
23 | #include <errno.h> |
---|
24 | |
---|
25 | RTEMS_STATIC_ASSERT( |
---|
26 | offsetof( Sem_Control, Queue ) |
---|
27 | == offsetof( struct _Semaphore_Control, _Queue ), |
---|
28 | SEMAPHORE_CONTROL_QUEUE |
---|
29 | ); |
---|
30 | |
---|
31 | RTEMS_STATIC_ASSERT( |
---|
32 | offsetof( Sem_Control, count ) |
---|
33 | == offsetof( struct _Semaphore_Control, _count ), |
---|
34 | SEMAPHORE_CONTROL_COUNT |
---|
35 | ); |
---|
36 | |
---|
37 | RTEMS_STATIC_ASSERT( |
---|
38 | sizeof( Sem_Control ) == sizeof( struct _Semaphore_Control ), |
---|
39 | SEMAPHORE_CONTROL_SIZE |
---|
40 | ); |
---|
41 | |
---|
42 | void _Semaphore_Wait( struct _Semaphore_Control *_sem ) |
---|
43 | { |
---|
44 | Sem_Control *sem; |
---|
45 | ISR_Level level; |
---|
46 | Thread_queue_Context queue_context; |
---|
47 | Thread_Control *executing; |
---|
48 | unsigned int count; |
---|
49 | |
---|
50 | sem = _Sem_Get( _sem ); |
---|
51 | _Thread_queue_Context_initialize( &queue_context ); |
---|
52 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
---|
53 | executing = _Sem_Queue_acquire_critical( sem, &queue_context ); |
---|
54 | |
---|
55 | count = sem->count; |
---|
56 | if ( RTEMS_PREDICT_TRUE( count > 0 ) ) { |
---|
57 | sem->count = count - 1; |
---|
58 | _Sem_Queue_release( sem, level, &queue_context ); |
---|
59 | } else { |
---|
60 | _Thread_queue_Context_set_thread_state( |
---|
61 | &queue_context, |
---|
62 | STATES_WAITING_FOR_SEMAPHORE |
---|
63 | ); |
---|
64 | _Thread_queue_Context_set_enqueue_do_nothing_extra( &queue_context ); |
---|
65 | _Thread_queue_Context_set_ISR_level( &queue_context, level ); |
---|
66 | _Thread_queue_Enqueue( |
---|
67 | &sem->Queue.Queue, |
---|
68 | SEMAPHORE_TQ_OPERATIONS, |
---|
69 | executing, |
---|
70 | &queue_context |
---|
71 | ); |
---|
72 | } |
---|
73 | } |
---|
74 | |
---|
75 | int _Semaphore_Wait_timed_ticks( struct _Semaphore_Control *_sem, uint32_t ticks ) |
---|
76 | { |
---|
77 | Sem_Control *sem; |
---|
78 | ISR_Level level; |
---|
79 | Thread_queue_Context queue_context; |
---|
80 | Thread_Control *executing; |
---|
81 | unsigned int count; |
---|
82 | |
---|
83 | sem = _Sem_Get( _sem ); |
---|
84 | _Thread_queue_Context_initialize( &queue_context ); |
---|
85 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
---|
86 | executing = _Sem_Queue_acquire_critical( sem, &queue_context ); |
---|
87 | |
---|
88 | count = sem->count; |
---|
89 | if ( RTEMS_PREDICT_TRUE( count > 0 ) ) { |
---|
90 | sem->count = count - 1; |
---|
91 | _Sem_Queue_release( sem, level, &queue_context ); |
---|
92 | return 0; |
---|
93 | } else { |
---|
94 | _Thread_queue_Context_set_thread_state( |
---|
95 | &queue_context, |
---|
96 | STATES_WAITING_FOR_SEMAPHORE |
---|
97 | ); |
---|
98 | _Thread_queue_Context_set_enqueue_timeout_ticks( &queue_context, ticks ); |
---|
99 | _Thread_queue_Context_set_ISR_level( &queue_context, level ); |
---|
100 | _Thread_queue_Enqueue( |
---|
101 | &sem->Queue.Queue, |
---|
102 | SEMAPHORE_TQ_OPERATIONS, |
---|
103 | executing, |
---|
104 | &queue_context |
---|
105 | ); |
---|
106 | return STATUS_GET_POSIX( _Thread_Wait_get_status( executing ) ); |
---|
107 | } |
---|
108 | } |
---|
109 | |
---|
110 | int _Semaphore_Try_wait( struct _Semaphore_Control *_sem ) |
---|
111 | { |
---|
112 | Sem_Control *sem; |
---|
113 | ISR_Level level; |
---|
114 | Thread_queue_Context queue_context; |
---|
115 | unsigned int count; |
---|
116 | int eno; |
---|
117 | |
---|
118 | sem = _Sem_Get( _sem ); |
---|
119 | _Thread_queue_Context_initialize( &queue_context ); |
---|
120 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
---|
121 | _Sem_Queue_acquire_critical( sem, &queue_context ); |
---|
122 | |
---|
123 | count = sem->count; |
---|
124 | if ( RTEMS_PREDICT_TRUE( count > 0 ) ) { |
---|
125 | sem->count = count - 1; |
---|
126 | eno = 0; |
---|
127 | } else { |
---|
128 | eno = EAGAIN; |
---|
129 | } |
---|
130 | |
---|
131 | _Sem_Queue_release( sem, level, &queue_context ); |
---|
132 | return eno; |
---|
133 | } |
---|
134 | |
---|
135 | void _Semaphore_Post( struct _Semaphore_Control *_sem ) |
---|
136 | { |
---|
137 | Sem_Control *sem; |
---|
138 | ISR_Level level; |
---|
139 | Thread_queue_Context queue_context; |
---|
140 | Thread_queue_Heads *heads; |
---|
141 | |
---|
142 | sem = _Sem_Get( _sem ); |
---|
143 | _Thread_queue_Context_initialize( &queue_context ); |
---|
144 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
---|
145 | _Sem_Queue_acquire_critical( sem, &queue_context ); |
---|
146 | |
---|
147 | heads = sem->Queue.Queue.heads; |
---|
148 | if ( RTEMS_PREDICT_TRUE( heads == NULL ) ) { |
---|
149 | ++sem->count; |
---|
150 | _Sem_Queue_release( sem, level, &queue_context ); |
---|
151 | } else { |
---|
152 | const Thread_queue_Operations *operations; |
---|
153 | Thread_Control *first; |
---|
154 | |
---|
155 | _Thread_queue_Context_set_ISR_level( &queue_context, level ); |
---|
156 | operations = SEMAPHORE_TQ_OPERATIONS; |
---|
157 | first = ( *operations->first )( heads ); |
---|
158 | |
---|
159 | _Thread_queue_Extract_critical( |
---|
160 | &sem->Queue.Queue, |
---|
161 | operations, |
---|
162 | first, |
---|
163 | &queue_context |
---|
164 | ); |
---|
165 | } |
---|
166 | } |
---|
167 | |
---|
168 | void _Semaphore_Post_binary( struct _Semaphore_Control *_sem ) |
---|
169 | { |
---|
170 | Sem_Control *sem; |
---|
171 | ISR_Level level; |
---|
172 | Thread_queue_Context queue_context; |
---|
173 | Thread_queue_Heads *heads; |
---|
174 | |
---|
175 | sem = _Sem_Get( _sem ); |
---|
176 | _Thread_queue_Context_initialize( &queue_context ); |
---|
177 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
---|
178 | _Sem_Queue_acquire_critical( sem, &queue_context ); |
---|
179 | |
---|
180 | heads = sem->Queue.Queue.heads; |
---|
181 | if ( RTEMS_PREDICT_TRUE( heads == NULL ) ) { |
---|
182 | sem->count = 1; |
---|
183 | _Sem_Queue_release( sem, level, &queue_context ); |
---|
184 | } else { |
---|
185 | const Thread_queue_Operations *operations; |
---|
186 | Thread_Control *first; |
---|
187 | |
---|
188 | _Thread_queue_Context_set_ISR_level( &queue_context, level ); |
---|
189 | operations = SEMAPHORE_TQ_OPERATIONS; |
---|
190 | first = ( *operations->first )( heads ); |
---|
191 | |
---|
192 | _Thread_queue_Extract_critical( |
---|
193 | &sem->Queue.Queue, |
---|
194 | operations, |
---|
195 | first, |
---|
196 | &queue_context |
---|
197 | ); |
---|
198 | } |
---|
199 | } |
---|