diff options
| author | Keith Packard <keithp@keithp.com> | 2012-08-26 09:49:34 -0700 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2012-08-26 09:49:34 -0700 |
| commit | d13d0fbfcb0fd6d8a1af46f6270a968d746c830e (patch) | |
| tree | 2d11bfe1903361b07a1ce31c95db755f8e7d9f8d | |
| parent | 1c9baa88d6cd931c66d453674322908eb267ba4c (diff) | |
altos: Make ao_cur_task_index track ao_cur_task in ao_yield
This keeps the two main task references (index and pointer) in
agreement during task switching, avoiding an extra assignment at the
end of the task switching loop.
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | src/core/ao_task.c | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/src/core/ao_task.c b/src/core/ao_task.c index 4011a36e..4593bd79 100644 --- a/src/core/ao_task.c +++ b/src/core/ao_task.c @@ -82,39 +82,36 @@ ao_yield(void) ao_arch_naked_define ao_arch_isr_stack(); -#if CHECK_STACK +#if AO_CHECK_STACK in_yield = 1; #endif /* Find a task to run. If there isn't any runnable task, * this loop will run forever, which is just fine */ { - __pdata uint8_t ao_next_task_index = ao_cur_task_index; + __pdata uint8_t ao_last_task_index = ao_cur_task_index; for (;;) { - ++ao_next_task_index; - if (ao_next_task_index == ao_num_tasks) - ao_next_task_index = 0; + ++ao_cur_task_index; + if (ao_cur_task_index == ao_num_tasks) + ao_cur_task_index = 0; + + ao_cur_task = ao_tasks[ao_cur_task_index]; - ao_cur_task = ao_tasks[ao_next_task_index]; - if (ao_cur_task->wchan == NULL) { - ao_cur_task_index = ao_next_task_index; + /* Check for ready task */ + if (ao_cur_task->wchan == NULL) 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; + (int16_t) (ao_time() - ao_cur_task->alarm) >= 0) break; - } /* Enter lower power mode when there isn't anything to do */ - if (ao_next_task_index == ao_cur_task_index) { + if (ao_cur_task_index == ao_last_task_index) ao_arch_cpu_idle(); - } } } -#if CHECK_STACK +#if AO_CHECK_STACK cli(); in_yield = 0; #endif @@ -177,7 +174,7 @@ ao_exit(void) void ao_task_info(void) { - uint8_t i; + uint8_t i; __xdata struct ao_task *task; for (i = 0; i < ao_num_tasks; i++) { |