「App:Library:LVGL:docs:Porting:Operating system and interrupts」の版間の差分
| 22行目: | 22行目: | ||
== Tasks and threads == | == Tasks and threads == | ||
| − | If you need to use real tasks or threads, you need a mutex which should be invoked before the call of <code>lv_timer_handler</code> and released after it. Also, you have to use the same mutex in other tasks and threads around every LVGL (<code>lv_...</code>) related function call and code. This way you can use LVGL in a real multitasking environment. Just make use of a mutex to avoid the concurrent calling of LVGL functions. | + | If you need to use real tasks or threads, you need a mutex which should be invoked before the call of <code style="color: #bb0000;">lv_timer_handler</code> and released after it. Also, you have to use the same mutex in other tasks and threads around every LVGL (<code style="color: #bb0000;">lv_...</code>) related function call and code. This way you can use LVGL in a real multitasking environment. Just make use of a mutex to avoid the concurrent calling of LVGL functions. |
Here is some pseudocode to illustrate the concept: | Here is some pseudocode to illustrate the concept: | ||
| 55行目: | 55行目: | ||
== Interrupts == | == Interrupts == | ||
| − | Try to avoid calling LVGL functions from interrupt handlers (except <code>lv_tick_inc()</code> and <code>lv_disp_flush_ready()</code>). But if you need to do this you have to disable the interrupt which uses LVGL functions while <code>lv_timer_handler</code> is running. | + | Try to avoid calling LVGL functions from interrupt handlers (except <code style="color: #bb0000;">lv_tick_inc()</code> and <code style="color: #bb0000;">lv_disp_flush_ready()</code>). But if you need to do this you have to disable the interrupt which uses LVGL functions while <code style="color: #bb0000;">lv_timer_handler</code> is running. |
| − | It's a better approach to simply set a flag or some value in the interrupt, and periodically check it in an LVGL timer (which is run by <code>lv_timer_handler</code>). | + | It's a better approach to simply set a flag or some value in the interrupt, and periodically check it in an LVGL timer (which is run by <code style="color: #bb0000;">lv_timer_handler</code>). |
2022年6月22日 (水) 14:35時点における版
https://docs.lvgl.io/8.2/porting/os.html
| 英文 | 自動翻訳 |
|---|---|
Operating system and interrupts
LVGL is not thread-safe by default.
However, in the following conditions it's valid to call LVGL related functions:
- In events. Learn more in Events.
- In lv_timer. Learn more in Timers.
Tasks and threads
If you need to use real tasks or threads, you need a mutex which should be invoked before the call of lv_timer_handler and released after it. Also, you have to use the same mutex in other tasks and threads around every LVGL (lv_...) related function call and code. This way you can use LVGL in a real multitasking environment. Just make use of a mutex to avoid the concurrent calling of LVGL functions.
Here is some pseudocode to illustrate the concept:
static mutex_t lvgl_mutex;
void lvgl_thread(void)
{
while(1) {
mutex_lock(&lvgl_mutex);
lv_task_handler();
mutex_unlock(&lvgl_mutex);
thread_sleep(10); /* sleep for 10 ms */
}
}
void other_thread(void)
{
/* You must always hold the mutex while using LVGL APIs */
mutex_lock(&lvgl_mutex);
lv_obj_t *img = lv_img_create(lv_scr_act());
mutex_unlock(&lvgl_mutex);
while(1) {
mutex_lock(&lvgl_mutex);
/* change to the next image */
lv_img_set_src(img, next_image);
mutex_unlock(&lvgl_mutex);
thread_sleep(2000);
}
}
Interrupts
Try to avoid calling LVGL functions from interrupt handlers (except lv_tick_inc() and lv_disp_flush_ready()). But if you need to do this you have to disable the interrupt which uses LVGL functions while lv_timer_handler is running.
It's a better approach to simply set a flag or some value in the interrupt, and periodically check it in an LVGL timer (which is run by lv_timer_handler).
