「App:Library:LVGL:docs:Porting:Operating system and interrupts」の版間の差分
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Here is some pseudocode to illustrate the concept: | Here is some pseudocode to illustrate the concept: | ||
static mutex_t lvgl_mutex; | static mutex_t lvgl_mutex; | ||
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void lvgl_thread(void) | void lvgl_thread(void) | ||
{ | { | ||
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} | } | ||
} | } | ||
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== Interrupts == | == Interrupts == |
2022年6月22日 (水) 14:34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
).