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>
27 #define AO_NO_TASK_INDEX 0xff
29 __xdata struct ao_task * __xdata ao_tasks[AO_NUM_TASKS];
30 __data uint8_t ao_num_tasks;
31 __data uint8_t ao_cur_task_index;
32 __xdata struct ao_task *__data ao_cur_task;
34 #ifdef ao_arch_task_globals
38 #define AO_CHECK_STACK 0
41 static uint8_t in_yield;
43 static inline void ao_check_stack(void) {
45 if (!in_yield && ao_cur_task && &q < &ao_cur_task->stack[0])
46 ao_panic(AO_PANIC_STACK);
49 #define ao_check_stack()
53 ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
57 if (ao_num_tasks == AO_NUM_TASKS)
58 ao_panic(AO_PANIC_NO_TASK);
59 for (task_id = 1; task_id != 0; task_id++) {
60 for (t = 0; t < ao_num_tasks; t++)
61 if (ao_tasks[t]->task_id == task_id)
63 if (t == ao_num_tasks)
66 ao_tasks[ao_num_tasks++] = task;
67 task->task_id = task_id;
71 * Construct a stack frame so that it will 'return'
72 * to the start of the task
74 ao_arch_init_stack(task, start);
77 __xdata uint8_t ao_idle;
79 /* Task switching function. This must not use any stack variables */
81 ao_yield(void) ao_arch_naked_define
85 if (ao_cur_task_index == AO_NO_TASK_INDEX)
86 ao_cur_task_index = ao_num_tasks-1;
89 #if HAS_SAMPLE_PROFILE
90 uint16_t tick = ao_sample_profile_timer_value();
91 uint16_t run = tick - ao_cur_task->start;
92 if (run > ao_cur_task->max_run)
93 ao_cur_task->max_run = run;
94 ++ao_cur_task->yields;
104 /* Find a task to run. If there isn't any runnable task,
105 * this loop will run forever, which is just fine
108 __pdata uint8_t ao_last_task_index = ao_cur_task_index;
111 if (ao_cur_task_index == ao_num_tasks)
112 ao_cur_task_index = 0;
114 ao_cur_task = ao_tasks[ao_cur_task_index];
116 /* Check for ready task */
117 if (ao_cur_task->wchan == NULL)
120 /* Check if the alarm is set for a time which has passed */
121 if (ao_cur_task->alarm &&
122 (int16_t) (ao_time() - ao_cur_task->alarm) >= 0)
125 /* Enter lower power mode when there isn't anything to do */
126 if (ao_cur_task_index == ao_last_task_index)
129 #if HAS_SAMPLE_PROFILE
130 ao_cur_task->start = ao_sample_profile_timer_value();
134 ao_mpu_stack_guard(ao_cur_task->stack);
140 ao_arch_restore_stack();
144 ao_sleep(__xdata void *wchan)
146 ao_cur_task->wchan = wchan;
148 if (ao_cur_task->wchan) {
149 ao_cur_task->wchan = NULL;
150 ao_cur_task->alarm = 0;
157 ao_wakeup(__xdata void *wchan)
162 for (i = 0; i < ao_num_tasks; i++)
163 if (ao_tasks[i]->wchan == wchan)
164 ao_tasks[i]->wchan = NULL;
168 ao_alarm(uint16_t delay)
170 /* Make sure we sleep *at least* delay ticks, which means adding
171 * one to account for the fact that we may be close to the next tick
173 if (!(ao_cur_task->alarm = ao_time() + delay + 1))
174 ao_cur_task->alarm = 1;
180 ao_cur_task->alarm = 0;
183 static __xdata uint8_t ao_forever;
186 ao_delay(uint16_t ticks)
189 ao_sleep(&ao_forever);
199 for (i = ao_cur_task_index; i < ao_num_tasks; i++)
200 ao_tasks[i] = ao_tasks[i+1];
201 ao_cur_task_index = AO_NO_TASK_INDEX;
204 /* we'll never get back here */
211 __xdata struct ao_task *task;
213 for (i = 0; i < ao_num_tasks; i++) {
215 printf("%12s: wchan %04x\n",
222 ao_start_scheduler(void)
224 ao_cur_task_index = AO_NO_TASK_INDEX;