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()
58 #define ao_task_irq_check() ao_arch_irq_check()
60 #define ao_task_irq_check()
65 #define SLEEP_HASH_SIZE 17
67 static struct ao_list run_queue;
68 static struct ao_list alarm_queue;
69 static struct ao_list sleep_queue[SLEEP_HASH_SIZE];
72 ao_task_to_run_queue(struct ao_task *task)
75 ao_list_del(&task->queue);
76 ao_list_append(&task->queue, &run_queue);
79 static struct ao_list *
80 ao_task_sleep_queue(void *wchan)
82 return &sleep_queue[(uintptr_t) wchan % SLEEP_HASH_SIZE];
86 ao_task_to_sleep_queue(struct ao_task *task, void *wchan)
89 ao_list_del(&task->queue);
90 ao_list_append(&task->queue, ao_task_sleep_queue(wchan));
95 ao_task_validate_alarm_queue(void)
97 struct ao_task *alarm, *prev = NULL;
100 if (ao_list_is_empty(&alarm_queue))
102 ao_list_for_each_entry(alarm, &alarm_queue, struct ao_task, alarm_queue) {
104 if ((int16_t) (alarm->alarm - prev->alarm) < 0) {
110 for (i = 0; i < ao_num_tasks; i++) {
113 if (ao_list_is_empty(&alarm->alarm_queue))
116 if (!ao_list_is_empty(&alarm->alarm_queue))
120 if (ao_task_alarm_tick != ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm)
124 #define ao_task_validate_alarm_queue()
127 uint16_t ao_task_alarm_tick;
130 ao_task_to_alarm_queue(struct ao_task *task)
132 struct ao_task *alarm;
134 ao_list_for_each_entry(alarm, &alarm_queue, struct ao_task, alarm_queue) {
135 if ((int16_t) (alarm->alarm - task->alarm) >= 0) {
136 ao_list_insert(&task->alarm_queue, alarm->alarm_queue.prev);
137 ao_task_alarm_tick = ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm;
138 ao_task_validate_alarm_queue();
142 ao_list_append(&task->alarm_queue, &alarm_queue);
143 ao_task_alarm_tick = ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm;
144 ao_task_validate_alarm_queue();
148 ao_task_from_alarm_queue(struct ao_task *task)
151 ao_list_del(&task->alarm_queue);
152 if (ao_list_is_empty(&alarm_queue))
153 ao_task_alarm_tick = 0;
155 ao_task_alarm_tick = ao_list_first_entry(&alarm_queue, struct ao_task, alarm_queue)->alarm;
156 ao_task_validate_alarm_queue();
160 ao_task_init_queue(struct ao_task *task)
162 ao_list_init(&task->queue);
163 ao_list_init(&task->alarm_queue);
167 ao_task_exit_queue(struct ao_task *task)
170 ao_list_del(&task->queue);
171 ao_list_del(&task->alarm_queue);
175 ao_task_check_alarm(uint16_t tick)
177 struct ao_task *alarm, *next;
180 ao_list_for_each_entry_safe(alarm, next, &alarm_queue, struct ao_task, alarm_queue) {
181 if ((int16_t) (tick - alarm->alarm) < 0)
184 ao_task_from_alarm_queue(alarm);
185 ao_task_to_run_queue(alarm);
193 ao_list_init(&run_queue);
194 ao_list_init(&alarm_queue);
195 ao_task_alarm_tick = 0;
196 for (i = 0; i < SLEEP_HASH_SIZE; i++)
197 ao_list_init(&sleep_queue[i]);
202 ao_task_validate_queue(struct ao_task *task)
207 struct ao_list *queue;
209 flags = ao_arch_irqsave();
211 queue = ao_task_sleep_queue(task->wchan);
217 ao_list_for_each_entry(m, queue, struct ao_task, queue) {
223 ao_arch_irqrestore(flags);
228 ao_task_validate_alarm(struct ao_task *task)
234 flags = ao_arch_irqsave();
235 if (task->alarm == 0)
237 ao_list_for_each_entry(m, &alarm_queue, struct ao_task, alarm_queue) {
242 if ((int16_t) (m->alarm - task->alarm) > 0)
245 if ((int16_t) (task->alarm - m->alarm) > 0)
250 ao_arch_irqrestore(flags);
256 ao_task_validate(void)
259 struct ao_task *task;
262 for (i = 0; i < ao_num_tasks; i++) {
264 ret = ao_task_validate_queue(task);
267 printf ("sleeping task not on sleep queue %s %08x\n",
268 task->name, task->wchan);
270 printf ("running task not on run queue %s\n",
273 ret = ao_task_validate_alarm(task);
276 printf ("alarm task not on alarm queue %s %d\n",
277 task->name, task->alarm);
279 printf ("alarm queue has sooner entries after %s %d\n",
280 task->name, task->alarm);
282 printf ("alarm queue has later entries before %s %d\n",
283 task->name, task->alarm);
289 #endif /* HAS_TASK_QUEUE */
292 ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
296 if (ao_num_tasks == AO_NUM_TASKS)
297 ao_panic(AO_PANIC_NO_TASK);
298 for (task_id = 1; task_id != 0; task_id++) {
299 for (t = 0; t < ao_num_tasks; t++)
300 if (ao_tasks[t]->task_id == task_id)
302 if (t == ao_num_tasks)
305 task->task_id = task_id;
309 * Construct a stack frame so that it will 'return'
310 * to the start of the task
312 ao_arch_init_stack(task, start);
315 ao_task_init_queue(task);
316 ao_task_to_run_queue(task);
318 ao_tasks[ao_num_tasks] = task;
323 __data uint8_t ao_task_minimize_latency;
325 /* Task switching function. This must not use any stack variables */
327 ao_yield(void) ao_arch_naked_define
332 if (ao_cur_task == NULL)
333 ao_cur_task = ao_tasks[ao_num_tasks-1];
335 if (ao_cur_task_index == AO_NO_TASK_INDEX)
336 ao_cur_task_index = ao_num_tasks-1;
340 #if HAS_SAMPLE_PROFILE
341 uint16_t tick = ao_sample_profile_timer_value();
342 uint16_t run = tick - ao_cur_task->start;
343 if (run > ao_cur_task->max_run)
344 ao_cur_task->max_run = run;
345 ++ao_cur_task->yields;
347 ao_arch_save_stack();
352 if (ao_task_minimize_latency)
353 ao_arch_release_interrupts();
356 ao_arch_block_interrupts();
361 /* Find a task to run. If there isn't any runnable task,
362 * this loop will run forever, which is just fine
365 /* If the current task is running, move it to the
366 * end of the queue to allow other tasks a chance
368 if (ao_cur_task->wchan == NULL)
369 ao_task_to_run_queue(ao_cur_task);
371 ao_arch_memory_barrier();
372 if (!ao_list_is_empty(&run_queue))
374 /* Wait for interrupts when there's nothing ready */
375 ao_arch_wait_interrupt();
377 ao_cur_task = ao_list_first_entry(&run_queue, struct ao_task, queue);
380 __pdata uint8_t ao_last_task_index = ao_cur_task_index;
383 if (ao_cur_task_index == ao_num_tasks)
384 ao_cur_task_index = 0;
386 ao_cur_task = ao_tasks[ao_cur_task_index];
388 /* Check for ready task */
389 if (ao_cur_task->wchan == NULL)
392 /* Check if the alarm is set for a time which has passed */
393 if (ao_cur_task->alarm &&
394 (int16_t) (ao_time() - ao_cur_task->alarm) >= 0)
397 /* Wait for interrupts when there's nothing ready */
398 if (ao_cur_task_index == ao_last_task_index && !ao_task_minimize_latency)
399 ao_arch_wait_interrupt();
403 #if HAS_SAMPLE_PROFILE
404 ao_cur_task->start = ao_sample_profile_timer_value();
407 ao_mpu_stack_guard(ao_cur_task->stack);
412 ao_arch_restore_stack();
416 ao_sleep(__xdata void *wchan)
420 flags = ao_arch_irqsave();
422 ao_cur_task->wchan = wchan;
424 ao_task_to_sleep_queue(ao_cur_task, wchan);
425 ao_arch_irqrestore(flags);
428 if (ao_cur_task->wchan) {
429 ao_cur_task->wchan = NULL;
430 ao_cur_task->alarm = 0;
437 ao_wakeup(__xdata void *wchan) __reentrant
439 ao_validate_cur_stack();
441 struct ao_task *sleep, *next;
442 struct ao_list *sleep_queue;
445 if (ao_num_tasks == 0)
447 sleep_queue = ao_task_sleep_queue(wchan);
448 flags = ao_arch_irqsave();
449 ao_list_for_each_entry_safe(sleep, next, sleep_queue, struct ao_task, queue) {
450 if (sleep->wchan == wchan) {
452 ao_task_to_run_queue(sleep);
455 ao_arch_irqrestore(flags);
459 for (i = 0; i < ao_num_tasks; i++)
460 if (ao_tasks[i]->wchan == wchan)
461 ao_tasks[i]->wchan = NULL;
468 ao_sleep_for(__xdata void *wchan, uint16_t timeout)
474 flags = ao_arch_irqsave();
476 /* Make sure we sleep *at least* delay ticks, which means adding
477 * one to account for the fact that we may be close to the next tick
479 if (!(ao_cur_task->alarm = ao_time() + timeout + 1))
480 ao_cur_task->alarm = 1;
482 ao_task_to_alarm_queue(ao_cur_task);
483 ao_arch_irqrestore(flags);
486 ret = ao_sleep(wchan);
491 flags = ao_arch_irqsave();
493 ao_cur_task->alarm = 0;
495 ao_task_from_alarm_queue(ao_cur_task);
496 ao_arch_irqrestore(flags);
502 static __xdata uint8_t ao_forever;
505 ao_delay(uint16_t ticks)
507 ao_sleep_for(&ao_forever, ticks);
514 ao_arch_block_interrupts();
517 for (i = 0; i < ao_num_tasks; i++)
518 if (ao_tasks[i] == ao_cur_task)
520 ao_task_exit_queue(ao_cur_task);
522 i = ao_cur_task_index;
523 ao_cur_task_index = AO_NO_TASK_INDEX;
525 for (; i < ao_num_tasks; i++)
526 ao_tasks[i] = ao_tasks[i+1];
529 /* we'll never get back here */
537 __xdata struct ao_task *task;
539 for (i = 0; i < ao_num_tasks; i++) {
541 printf("%12s: wchan %04x\n",
545 #if HAS_TASK_QUEUE && DEBUG
552 ao_start_scheduler(void)
555 ao_cur_task_index = AO_NO_TASK_INDEX;
558 #if HAS_ARCH_START_SCHEDULER
559 ao_arch_start_scheduler();