1 | /* |
---|
2 | * Thread Queue Handler |
---|
3 | * |
---|
4 | * |
---|
5 | * COPYRIGHT (c) 1989-1999. |
---|
6 | * On-Line Applications Research Corporation (OAR). |
---|
7 | * |
---|
8 | * The license and distribution terms for this file may be |
---|
9 | * found in the file LICENSE in this distribution or at |
---|
10 | * http://www.OARcorp.com/rtems/license.html. |
---|
11 | * |
---|
12 | * $Id$ |
---|
13 | */ |
---|
14 | |
---|
15 | #include <rtems/system.h> |
---|
16 | #include <rtems/score/chain.h> |
---|
17 | #include <rtems/score/isr.h> |
---|
18 | #include <rtems/score/object.h> |
---|
19 | #include <rtems/score/states.h> |
---|
20 | #include <rtems/score/thread.h> |
---|
21 | #include <rtems/score/threadq.h> |
---|
22 | #include <rtems/score/tqdata.h> |
---|
23 | |
---|
24 | /*PAGE |
---|
25 | * |
---|
26 | * _Thread_queue_Enqueue_priority |
---|
27 | * |
---|
28 | * This routine blocks a thread, places it on a thread, and optionally |
---|
29 | * starts a timeout timer. |
---|
30 | * |
---|
31 | * Input parameters: |
---|
32 | * the_thread_queue - pointer to threadq |
---|
33 | * thread - thread to insert |
---|
34 | * timeout - timeout interval in ticks |
---|
35 | * |
---|
36 | * Output parameters: NONE |
---|
37 | * |
---|
38 | * INTERRUPT LATENCY: |
---|
39 | * forward less than |
---|
40 | * forward equal |
---|
41 | */ |
---|
42 | |
---|
43 | void _Thread_queue_Enqueue_priority( |
---|
44 | Thread_queue_Control *the_thread_queue, |
---|
45 | Thread_Control *the_thread, |
---|
46 | Watchdog_Interval timeout |
---|
47 | ) |
---|
48 | { |
---|
49 | Priority_Control search_priority; |
---|
50 | Thread_Control *search_thread; |
---|
51 | ISR_Level level; |
---|
52 | Chain_Control *header; |
---|
53 | unsigned32 header_index; |
---|
54 | Chain_Node *the_node; |
---|
55 | Chain_Node *next_node; |
---|
56 | Chain_Node *previous_node; |
---|
57 | Chain_Node *search_node; |
---|
58 | Priority_Control priority; |
---|
59 | States_Control block_state; |
---|
60 | Thread_queue_States sync_state; |
---|
61 | |
---|
62 | _Chain_Initialize_empty( &the_thread->Wait.Block2n ); |
---|
63 | |
---|
64 | priority = the_thread->current_priority; |
---|
65 | header_index = _Thread_queue_Header_number( priority ); |
---|
66 | header = &the_thread_queue->Queues.Priority[ header_index ]; |
---|
67 | block_state = the_thread_queue->state; |
---|
68 | |
---|
69 | if ( _Thread_queue_Is_reverse_search( priority ) ) |
---|
70 | goto restart_reverse_search; |
---|
71 | |
---|
72 | restart_forward_search: |
---|
73 | search_priority = PRIORITY_MINIMUM - 1; |
---|
74 | _ISR_Disable( level ); |
---|
75 | search_thread = (Thread_Control *) header->first; |
---|
76 | while ( !_Chain_Is_tail( header, (Chain_Node *)search_thread ) ) { |
---|
77 | search_priority = search_thread->current_priority; |
---|
78 | if ( priority <= search_priority ) |
---|
79 | break; |
---|
80 | |
---|
81 | #if ( CPU_UNROLL_ENQUEUE_PRIORITY == TRUE ) |
---|
82 | search_thread = (Thread_Control *) search_thread->Object.Node.next; |
---|
83 | if ( _Chain_Is_tail( header, (Chain_Node *)search_thread ) ) |
---|
84 | break; |
---|
85 | search_priority = search_thread->current_priority; |
---|
86 | if ( priority <= search_priority ) |
---|
87 | break; |
---|
88 | #endif |
---|
89 | _ISR_Flash( level ); |
---|
90 | if ( !_States_Are_set( search_thread->current_state, block_state) ) { |
---|
91 | _ISR_Enable( level ); |
---|
92 | goto restart_forward_search; |
---|
93 | } |
---|
94 | search_thread = |
---|
95 | (Thread_Control *)search_thread->Object.Node.next; |
---|
96 | } |
---|
97 | |
---|
98 | if ( the_thread_queue->sync_state != THREAD_QUEUE_NOTHING_HAPPENED ) |
---|
99 | goto synchronize; |
---|
100 | |
---|
101 | the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED; |
---|
102 | |
---|
103 | if ( priority == search_priority ) |
---|
104 | goto equal_priority; |
---|
105 | |
---|
106 | search_node = (Chain_Node *) search_thread; |
---|
107 | previous_node = search_node->previous; |
---|
108 | the_node = (Chain_Node *) the_thread; |
---|
109 | |
---|
110 | the_node->next = search_node; |
---|
111 | the_node->previous = previous_node; |
---|
112 | previous_node->next = the_node; |
---|
113 | search_node->previous = the_node; |
---|
114 | _ISR_Enable( level ); |
---|
115 | return; |
---|
116 | |
---|
117 | restart_reverse_search: |
---|
118 | search_priority = PRIORITY_MAXIMUM + 1; |
---|
119 | |
---|
120 | _ISR_Disable( level ); |
---|
121 | search_thread = (Thread_Control *) header->last; |
---|
122 | while ( !_Chain_Is_head( header, (Chain_Node *)search_thread ) ) { |
---|
123 | search_priority = search_thread->current_priority; |
---|
124 | if ( priority >= search_priority ) |
---|
125 | break; |
---|
126 | #if ( CPU_UNROLL_ENQUEUE_PRIORITY == TRUE ) |
---|
127 | search_thread = (Thread_Control *) search_thread->Object.Node.previous; |
---|
128 | if ( _Chain_Is_head( header, (Chain_Node *)search_thread ) ) |
---|
129 | break; |
---|
130 | search_priority = search_thread->current_priority; |
---|
131 | if ( priority >= search_priority ) |
---|
132 | break; |
---|
133 | #endif |
---|
134 | _ISR_Flash( level ); |
---|
135 | if ( !_States_Are_set( search_thread->current_state, block_state) ) { |
---|
136 | _ISR_Enable( level ); |
---|
137 | goto restart_reverse_search; |
---|
138 | } |
---|
139 | search_thread = (Thread_Control *) |
---|
140 | search_thread->Object.Node.previous; |
---|
141 | } |
---|
142 | |
---|
143 | if ( the_thread_queue->sync_state != THREAD_QUEUE_NOTHING_HAPPENED ) |
---|
144 | goto synchronize; |
---|
145 | |
---|
146 | the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED; |
---|
147 | |
---|
148 | if ( priority == search_priority ) |
---|
149 | goto equal_priority; |
---|
150 | |
---|
151 | search_node = (Chain_Node *) search_thread; |
---|
152 | next_node = search_node->next; |
---|
153 | the_node = (Chain_Node *) the_thread; |
---|
154 | |
---|
155 | the_node->next = next_node; |
---|
156 | the_node->previous = search_node; |
---|
157 | search_node->next = the_node; |
---|
158 | next_node->previous = the_node; |
---|
159 | _ISR_Enable( level ); |
---|
160 | return; |
---|
161 | |
---|
162 | equal_priority: /* add at end of priority group */ |
---|
163 | search_node = _Chain_Tail( &search_thread->Wait.Block2n ); |
---|
164 | previous_node = search_node->previous; |
---|
165 | the_node = (Chain_Node *) the_thread; |
---|
166 | |
---|
167 | the_node->next = search_node; |
---|
168 | the_node->previous = previous_node; |
---|
169 | previous_node->next = the_node; |
---|
170 | search_node->previous = the_node; |
---|
171 | _ISR_Enable( level ); |
---|
172 | return; |
---|
173 | |
---|
174 | synchronize: |
---|
175 | |
---|
176 | sync_state = the_thread_queue->sync_state; |
---|
177 | the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED; |
---|
178 | |
---|
179 | switch ( sync_state ) { |
---|
180 | case THREAD_QUEUE_SYNCHRONIZED: |
---|
181 | /* |
---|
182 | * This should never happen. It indicates that someone did not |
---|
183 | * enter a thread queue critical section. |
---|
184 | */ |
---|
185 | break; |
---|
186 | |
---|
187 | case THREAD_QUEUE_NOTHING_HAPPENED: |
---|
188 | /* |
---|
189 | * This should never happen. All of this was dealt with above. |
---|
190 | */ |
---|
191 | break; |
---|
192 | |
---|
193 | case THREAD_QUEUE_TIMEOUT: |
---|
194 | the_thread->Wait.return_code = the_thread->Wait.queue->timeout_status; |
---|
195 | _ISR_Enable( level ); |
---|
196 | break; |
---|
197 | |
---|
198 | case THREAD_QUEUE_SATISFIED: |
---|
199 | if ( _Watchdog_Is_active( &the_thread->Timer ) ) { |
---|
200 | _Watchdog_Deactivate( &the_thread->Timer ); |
---|
201 | _ISR_Enable( level ); |
---|
202 | (void) _Watchdog_Remove( &the_thread->Timer ); |
---|
203 | } else |
---|
204 | _ISR_Enable( level ); |
---|
205 | break; |
---|
206 | } |
---|
207 | |
---|
208 | /* |
---|
209 | * Global objects with thread queue's should not be operated on from an |
---|
210 | * ISR. But the sync code still must allow short timeouts to be processed |
---|
211 | * correctly. |
---|
212 | */ |
---|
213 | |
---|
214 | _Thread_Unblock( the_thread ); |
---|
215 | |
---|
216 | #if defined(RTEMS_MULTIPROCESSING) |
---|
217 | if ( !_Objects_Is_local_id( the_thread->Object.id ) ) |
---|
218 | _Thread_MP_Free_proxy( the_thread ); |
---|
219 | #endif |
---|
220 | } |
---|
221 | |
---|