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()
118 ao_task_to_alarm_queue(struct ao_task *task)
120 struct ao_task *alarm;
121 ao_list_for_each_entry(alarm, &alarm_queue, struct ao_task, alarm_queue) {
122 if ((int16_t) (alarm->alarm - task->alarm) >= 0) {
123 ao_list_insert(&task->alarm_queue, alarm->alarm_queue.prev);
124 ao_task_validate_alarm_queue();
128 ao_list_append(&task->alarm_queue, &alarm_queue);
129 ao_task_validate_alarm_queue();
133 ao_task_from_alarm_queue(struct ao_task *task)
135 ao_list_del(&task->alarm_queue);
136 ao_task_validate_alarm_queue();
140 ao_task_init_queue(struct ao_task *task)
142 ao_list_init(&task->queue);
143 ao_list_init(&task->alarm_queue);
147 ao_task_exit_queue(struct ao_task *task)
149 ao_list_del(&task->queue);
150 ao_list_del(&task->alarm_queue);
154 ao_task_check_alarm(uint16_t tick)
156 struct ao_task *alarm, *next;
159 if (ao_num_tasks == 0)
161 ao_list_for_each_entry_safe(alarm, next, &alarm_queue, struct ao_task, alarm_queue) {
162 if ((int16_t) (tick - alarm->alarm) < 0)
165 ao_task_from_alarm_queue(alarm);
166 ao_task_to_run_queue(alarm);
174 ao_list_init(&run_queue);
175 ao_list_init(&alarm_queue);
176 for (i = 0; i < SLEEP_HASH_SIZE; i++)
177 ao_list_init(&sleep_queue[i]);
182 ao_task_validate_queue(struct ao_task *task)
187 struct ao_list *queue;
189 flags = ao_arch_irqsave();
191 queue = ao_task_sleep_queue(task->wchan);
197 ao_list_for_each_entry(m, queue, struct ao_task, queue) {
203 ao_arch_irqrestore(flags);
208 ao_task_validate_alarm(struct ao_task *task)
214 flags = ao_arch_irqsave();
215 if (task->alarm == 0)
217 ao_list_for_each_entry(m, &alarm_queue, struct ao_task, alarm_queue) {
222 if ((int16_t) (m->alarm - task->alarm) > 0)
225 if ((int16_t) (task->alarm - m->alarm) > 0)
230 ao_arch_irqrestore(flags);
236 ao_task_validate(void)
239 struct ao_task *task;
242 for (i = 0; i < ao_num_tasks; i++) {
244 ret = ao_task_validate_queue(task);
247 printf ("sleeping task not on sleep queue %s %08x\n",
248 task->name, task->wchan);
250 printf ("running task not on run queue %s\n",
253 ret = ao_task_validate_alarm(task);
256 printf ("alarm task not on alarm queue %s %d\n",
257 task->name, task->alarm);
259 printf ("alarm queue has sooner entries after %s %d\n",
260 task->name, task->alarm);
262 printf ("alarm queue has later entries before %s %d\n",
263 task->name, task->alarm);
268 #define ao_task_validate()
272 #define ao_task_to_run_queue(task)
273 #define ao_task_to_alarm_queue(task)
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();
338 /* Find a task to run. If there isn't any runnable task,
339 * this loop will run forever, which is just fine
342 if (ao_cur_task->wchan == NULL) {
344 flags = ao_arch_irqsave();
345 ao_task_to_run_queue(ao_cur_task);
346 ao_arch_irqrestore(flags);
351 ao_arch_memory_barrier();
352 if (!ao_list_is_empty(&run_queue))
357 ao_cur_task = ao_list_first_entry(&run_queue, struct ao_task, queue);
360 __pdata uint8_t ao_last_task_index = ao_cur_task_index;
363 if (ao_cur_task_index == ao_num_tasks)
364 ao_cur_task_index = 0;
366 ao_cur_task = ao_tasks[ao_cur_task_index];
368 /* Check for ready task */
369 if (ao_cur_task->wchan == NULL)
372 /* Check if the alarm is set for a time which has passed */
373 if (ao_cur_task->alarm &&
374 (int16_t) (ao_time() - ao_cur_task->alarm) >= 0)
377 /* Enter lower power mode when there isn't anything to do */
378 if (ao_cur_task_index == ao_last_task_index)
381 #if HAS_SAMPLE_PROFILE
382 ao_cur_task->start = ao_sample_profile_timer_value();
387 ao_mpu_stack_guard(ao_cur_task->stack);
390 ao_arch_block_interrupts();
393 ao_arch_restore_stack();
397 ao_sleep(__xdata void *wchan)
401 flags = ao_arch_irqsave();
403 ao_cur_task->wchan = wchan;
405 ao_task_to_sleep_queue(ao_cur_task, wchan);
406 ao_arch_irqrestore(flags);
409 if (ao_cur_task->wchan) {
410 ao_cur_task->wchan = NULL;
411 ao_cur_task->alarm = 0;
418 ao_wakeup(__xdata void *wchan)
421 struct ao_task *sleep, *next;
422 struct ao_list *sleep_queue;
425 if (ao_num_tasks == 0)
427 sleep_queue = ao_task_sleep_queue(wchan);
428 flags = ao_arch_irqsave();
429 ao_list_for_each_entry_safe(sleep, next, sleep_queue, struct ao_task, queue) {
430 if (sleep->wchan == wchan) {
432 ao_task_to_run_queue(sleep);
435 ao_arch_irqrestore(flags);
438 for (i = 0; i < ao_num_tasks; i++)
439 if (ao_tasks[i]->wchan == wchan)
440 ao_tasks[i]->wchan = NULL;
446 ao_alarm(uint16_t delay)
450 /* Make sure we sleep *at least* delay ticks, which means adding
451 * one to account for the fact that we may be close to the next tick
453 flags = ao_arch_irqsave();
455 if (!(ao_cur_task->alarm = ao_time() + delay + 1))
456 ao_cur_task->alarm = 1;
458 ao_task_to_alarm_queue(ao_cur_task);
459 ao_arch_irqrestore(flags);
469 flags = ao_arch_irqsave();
471 ao_cur_task->alarm = 0;
473 ao_task_from_alarm_queue(ao_cur_task);
474 ao_arch_irqrestore(flags);
478 static __xdata uint8_t ao_forever;
481 ao_delay(uint16_t ticks)
484 ao_sleep(&ao_forever);
492 ao_arch_block_interrupts();
495 for (i = 0; i < ao_num_tasks; i++)
496 if (ao_tasks[i] == ao_cur_task)
498 ao_task_exit_queue(ao_cur_task);
500 i = ao_cur_task_index;
501 ao_cur_task_index = AO_NO_TASK_INDEX;
503 for (; i < ao_num_tasks; i++)
504 ao_tasks[i] = ao_tasks[i+1];
507 /* we'll never get back here */
514 __xdata struct ao_task *task;
516 for (i = 0; i < ao_num_tasks; i++) {
518 printf("%12s: wchan %04x\n",
528 ao_start_scheduler(void)
531 ao_cur_task_index = AO_NO_TASK_INDEX;