2 * Copyright © 2009 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 #if HAS_SAMPLE_PROFILE
21 #include <ao_sample_profile.h>
29 #define AO_NO_TASK_INDEX 0xff
31 __xdata struct ao_task * __xdata ao_tasks[AO_NUM_TASKS];
32 __data uint8_t ao_num_tasks;
33 __xdata struct ao_task *__data ao_cur_task;
36 static __data uint8_t ao_cur_task_index;
39 #ifdef ao_arch_task_globals
43 #define AO_CHECK_STACK 0
46 static uint8_t in_yield;
48 static inline void ao_check_stack(void) {
50 if (!in_yield && ao_cur_task && &q < &ao_cur_task->stack[0])
51 ao_panic(AO_PANIC_STACK);
54 #define ao_check_stack()
59 #define SLEEP_HASH_SIZE 17
61 static struct ao_list run_queue;
62 static struct ao_list alarm_queue;
63 static struct ao_list sleep_queue[SLEEP_HASH_SIZE];
66 ao_task_to_run_queue(struct ao_task *task)
68 ao_list_del(&task->queue);
69 ao_list_append(&task->queue, &run_queue);
72 static struct ao_list *
73 ao_task_sleep_queue(void *wchan)
75 return &sleep_queue[(uintptr_t) wchan % SLEEP_HASH_SIZE];
79 ao_task_to_sleep_queue(struct ao_task *task, void *wchan)
81 ao_list_del(&task->queue);
82 ao_list_append(&task->queue, ao_task_sleep_queue(wchan));
87 ao_task_validate_alarm_queue(void)
89 struct ao_task *alarm, *prev = NULL;
92 if (ao_list_is_empty(&alarm_queue))
94 ao_list_for_each_entry(alarm, &alarm_queue, struct ao_task, alarm_queue) {
96 if ((int16_t) (alarm->alarm - prev->alarm) < 0) {
102 for (i = 0; i < ao_num_tasks; i++) {
105 if (ao_list_is_empty(&alarm->alarm_queue))
108 if (!ao_list_is_empty(&alarm->alarm_queue))
114 #define ao_task_validate_alarm_queue()
117 uint16_t ao_task_alarm_tick;
120 ao_task_to_alarm_queue(struct ao_task *task)
122 struct ao_task *alarm;
123 ao_list_for_each_entry(alarm, &alarm_queue, struct ao_task, alarm_queue) {
124 if ((int16_t) (alarm->alarm - task->alarm) >= 0) {
125 ao_list_insert(&task->alarm_queue, alarm->alarm_queue.prev);
126 ao_task_validate_alarm_queue();
130 ao_list_append(&task->alarm_queue, &alarm_queue);
131 ao_task_alarm_tick = ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm;
132 ao_task_validate_alarm_queue();
136 ao_task_from_alarm_queue(struct ao_task *task)
138 ao_list_del(&task->alarm_queue);
139 if (ao_list_is_empty(&alarm_queue))
140 ao_task_alarm_tick = 0;
142 ao_task_alarm_tick = ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm;
143 ao_task_validate_alarm_queue();
147 ao_task_init_queue(struct ao_task *task)
149 ao_list_init(&task->queue);
150 ao_list_init(&task->alarm_queue);
154 ao_task_exit_queue(struct ao_task *task)
156 ao_list_del(&task->queue);
157 ao_list_del(&task->alarm_queue);
161 ao_task_check_alarm(uint16_t tick)
163 struct ao_task *alarm, *next;
165 ao_list_for_each_entry_safe(alarm, next, &alarm_queue, struct ao_task, alarm_queue) {
166 if ((int16_t) (tick - alarm->alarm) < 0)
169 ao_task_from_alarm_queue(alarm);
170 ao_task_to_run_queue(alarm);
178 ao_list_init(&run_queue);
179 ao_list_init(&alarm_queue);
180 ao_task_alarm_tick = 0;
181 for (i = 0; i < SLEEP_HASH_SIZE; i++)
182 ao_list_init(&sleep_queue[i]);
187 ao_task_validate_queue(struct ao_task *task)
192 struct ao_list *queue;
194 flags = ao_arch_irqsave();
196 queue = ao_task_sleep_queue(task->wchan);
202 ao_list_for_each_entry(m, queue, struct ao_task, queue) {
208 ao_arch_irqrestore(flags);
213 ao_task_validate_alarm(struct ao_task *task)
219 flags = ao_arch_irqsave();
220 if (task->alarm == 0)
222 ao_list_for_each_entry(m, &alarm_queue, struct ao_task, alarm_queue) {
227 if ((int16_t) (m->alarm - task->alarm) > 0)
230 if ((int16_t) (task->alarm - m->alarm) > 0)
235 ao_arch_irqrestore(flags);
241 ao_task_validate(void)
244 struct ao_task *task;
247 for (i = 0; i < ao_num_tasks; i++) {
249 ret = ao_task_validate_queue(task);
252 printf ("sleeping task not on sleep queue %s %08x\n",
253 task->name, task->wchan);
255 printf ("running task not on run queue %s\n",
258 ret = ao_task_validate_alarm(task);
261 printf ("alarm task not on alarm queue %s %d\n",
262 task->name, task->alarm);
264 printf ("alarm queue has sooner entries after %s %d\n",
265 task->name, task->alarm);
267 printf ("alarm queue has later entries before %s %d\n",
268 task->name, task->alarm);
274 #endif /* HAS_TASK_QUEUE */
277 ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
281 if (ao_num_tasks == AO_NUM_TASKS)
282 ao_panic(AO_PANIC_NO_TASK);
283 for (task_id = 1; task_id != 0; task_id++) {
284 for (t = 0; t < ao_num_tasks; t++)
285 if (ao_tasks[t]->task_id == task_id)
287 if (t == ao_num_tasks)
290 task->task_id = task_id;
294 * Construct a stack frame so that it will 'return'
295 * to the start of the task
297 ao_arch_init_stack(task, start);
300 ao_task_init_queue(task);
301 ao_task_to_run_queue(task);
303 ao_tasks[ao_num_tasks] = task;
308 /* Task switching function. This must not use any stack variables */
310 ao_yield(void) ao_arch_naked_define
315 if (ao_cur_task == NULL)
316 ao_cur_task = ao_tasks[ao_num_tasks-1];
318 if (ao_cur_task_index == AO_NO_TASK_INDEX)
319 ao_cur_task_index = ao_num_tasks-1;
323 #if HAS_SAMPLE_PROFILE
324 uint16_t tick = ao_sample_profile_timer_value();
325 uint16_t run = tick - ao_cur_task->start;
326 if (run > ao_cur_task->max_run)
327 ao_cur_task->max_run = run;
328 ++ao_cur_task->yields;
330 ao_arch_save_stack();
334 ao_arch_block_interrupts();
339 /* Find a task to run. If there isn't any runnable task,
340 * this loop will run forever, which is just fine
343 /* If the current task is running, move it to the
344 * end of the queue to allow other tasks a chance
346 if (ao_cur_task->wchan == NULL)
347 ao_task_to_run_queue(ao_cur_task);
350 ao_arch_memory_barrier();
351 if (!ao_list_is_empty(&run_queue))
353 /* Wait for interrupts when there's nothing ready */
354 ao_arch_wait_interrupt();
356 ao_cur_task = ao_list_first_entry(&run_queue, struct ao_task, queue);
359 __pdata uint8_t ao_last_task_index = ao_cur_task_index;
362 if (ao_cur_task_index == ao_num_tasks)
363 ao_cur_task_index = 0;
365 ao_cur_task = ao_tasks[ao_cur_task_index];
367 /* Check for ready task */
368 if (ao_cur_task->wchan == NULL)
371 /* Check if the alarm is set for a time which has passed */
372 if (ao_cur_task->alarm &&
373 (int16_t) (ao_time() - ao_cur_task->alarm) >= 0)
376 /* Wait for interrupts when there's nothing ready */
377 if (ao_cur_task_index == ao_last_task_index)
378 ao_arch_wait_interrupt();
382 #if HAS_SAMPLE_PROFILE
383 ao_cur_task->start = ao_sample_profile_timer_value();
386 ao_mpu_stack_guard(ao_cur_task->stack);
391 ao_arch_restore_stack();
395 ao_sleep(__xdata void *wchan)
399 flags = ao_arch_irqsave();
401 ao_cur_task->wchan = wchan;
403 ao_task_to_sleep_queue(ao_cur_task, wchan);
404 ao_arch_irqrestore(flags);
407 if (ao_cur_task->wchan) {
408 ao_cur_task->wchan = NULL;
409 ao_cur_task->alarm = 0;
416 ao_wakeup(__xdata void *wchan)
419 struct ao_task *sleep, *next;
420 struct ao_list *sleep_queue;
423 if (ao_num_tasks == 0)
425 sleep_queue = ao_task_sleep_queue(wchan);
426 flags = ao_arch_irqsave();
427 ao_list_for_each_entry_safe(sleep, next, sleep_queue, struct ao_task, queue) {
428 if (sleep->wchan == wchan) {
430 ao_task_to_run_queue(sleep);
433 ao_arch_irqrestore(flags);
436 for (i = 0; i < ao_num_tasks; i++)
437 if (ao_tasks[i]->wchan == wchan)
438 ao_tasks[i]->wchan = NULL;
444 ao_alarm(uint16_t delay)
448 /* Make sure we sleep *at least* delay ticks, which means adding
449 * one to account for the fact that we may be close to the next tick
451 flags = ao_arch_irqsave();
453 if (!(ao_cur_task->alarm = ao_time() + delay + 1))
454 ao_cur_task->alarm = 1;
456 ao_task_to_alarm_queue(ao_cur_task);
457 ao_arch_irqrestore(flags);
467 flags = ao_arch_irqsave();
469 ao_cur_task->alarm = 0;
471 ao_task_from_alarm_queue(ao_cur_task);
472 ao_arch_irqrestore(flags);
476 static __xdata uint8_t ao_forever;
479 ao_delay(uint16_t ticks)
482 ao_sleep(&ao_forever);
490 ao_arch_block_interrupts();
493 for (i = 0; i < ao_num_tasks; i++)
494 if (ao_tasks[i] == ao_cur_task)
496 ao_task_exit_queue(ao_cur_task);
498 i = ao_cur_task_index;
499 ao_cur_task_index = AO_NO_TASK_INDEX;
501 for (; i < ao_num_tasks; i++)
502 ao_tasks[i] = ao_tasks[i+1];
505 /* we'll never get back here */
512 __xdata struct ao_task *task;
514 for (i = 0; i < ao_num_tasks; i++) {
516 printf("%12s: wchan %04x\n",
520 #if HAS_TASK_QUEUE && DEBUG
526 ao_start_scheduler(void)
529 ao_cur_task_index = AO_NO_TASK_INDEX;