Tasks may move in task structure as a result of ao_exit

[fw/altos] / src / ao_task.c

diff --git a/src/ao_task.c b/src/ao_task.c
index 12b73943f0c1c73eec79064c4b97e8f0dc1f21ab..72c9d7d61f67216a71436ce9ffd7c4d0989c5bef 100644 (file)
--- a/src/ao_task.c
+++ b/src/ao_task.c
@@ -28,10 +28,19 @@ void
 ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
 {
        uint8_t __xdata *stack;
+       uint8_t task_id;
+       uint8_t t;
        if (ao_num_tasks == AO_NUM_TASKS)
                ao_panic(AO_PANIC_NO_TASK);
+       for (task_id = 1; task_id != 0; task_id++) {
+               for (t = 0; t < ao_num_tasks; t++)
+                       if (ao_tasks[t]->task_id == task_id)
+                               break;
+               if (t == ao_num_tasks)
+                       break;
+       }
        ao_tasks[ao_num_tasks++] = task;
-       task->task_id = ao_num_tasks;
+       task->task_id = task_id;
        task->name = name;
        /*
         * Construct a stack frame so that it will 'return'
@@ -93,7 +102,9 @@ ao_yield(void) _naked
                push    _bp
        _endasm;
 
-       if (ao_cur_task_index != AO_NO_TASK_INDEX)
+       if (ao_cur_task_index == AO_NO_TASK_INDEX)
+               ao_cur_task_index = ao_num_tasks-1;
+       else
        {
                uint8_t stack_len;
                __data uint8_t *stack_ptr;
@@ -127,6 +138,13 @@ ao_yield(void) _naked
                                break;
                        }
 
+                       /* Check if the alarm is set for a time which has passed */
+                       if (ao_cur_task->alarm &&
+                           (int16_t) (ao_time() - ao_cur_task->alarm) >= 0) {
+                               ao_cur_task_index = ao_next_task_index;
+                               break;
+                       }
+
                        /* Enter lower power mode when there isn't anything to do */
                        if (ao_next_task_index == ao_cur_task_index)
                                PCON = PCON_IDLE;
@@ -179,13 +197,20 @@ ao_yield(void) _naked
        _endasm;
 }
 
-void
+uint8_t
 ao_sleep(__xdata void *wchan)
 {
        __critical {
                ao_cur_task->wchan = wchan;
        }
        ao_yield();
+       if (ao_cur_task->wchan) {
+               ao_cur_task->wchan = NULL;
+               ao_cur_task->alarm = 0;
+               return 1;
+       }
+       ao_cur_task->alarm = 0;
+       return 0;
 }
 
 void
@@ -198,6 +223,34 @@ ao_wakeup(__xdata void *wchan)
                        ao_tasks[i]->wchan = NULL;
 }
 
+void
+ao_alarm(uint16_t delay)
+{
+       /* Make sure we sleep *at least* delay ticks, which means adding
+        * one to account for the fact that we may be close to the next tick
+        */
+       if (!(ao_cur_task->alarm = ao_time() + delay + 1))
+               ao_cur_task->alarm = 1;
+}
+
+void
+ao_wake_task(__xdata struct ao_task *task)
+{
+       task->wchan = NULL;
+}
+
+void
+ao_exit(void) __critical
+{
+       uint8_t i;
+       ao_num_tasks--;
+       for (i = ao_cur_task_index; i < ao_num_tasks; i++)
+               ao_tasks[i] = ao_tasks[i+1];
+       ao_cur_task_index = AO_NO_TASK_INDEX;
+       ao_yield();
+       /* we'll never get back here */
+}
+
 void
 ao_task_info(void)
 {