/******************************************************************************
 * @file    app_defer.c
 * @brief   ISR→任务上下文的延后执行标志位实现
 * @author  cyWu <1917507415@qq.com>
 * @date    2026.08.31
 * @version V1.0.0，首次发布
 ******************************************************************************/

#include "system/includes.h"
#include "app_defer.h"

/** 位掩码，volatile：request() 在中断上下文写，take()/is_pending()/cancel()
 *  在任务上下文读写，两侧都用 local_irq_disable/enable 包一下读改写，
 *  避免"任务侧正在清 A 位时中断侧设 B 位"这种读改写竞态把 B 位冲丢。 */
static volatile uint8_t s_flags;

void app_defer_request(AppDeferBit_t bit)
{
    if (bit >= APP_DEFER_MAX) {
        return;
    }
    local_irq_disable();
    s_flags |= (uint8_t)(1u << bit);
    local_irq_enable();
}

uint8_t app_defer_take(AppDeferBit_t bit)
{
    uint8_t was_set;

    if (bit >= APP_DEFER_MAX) {
        return 0;
    }
    local_irq_disable();
    was_set = (s_flags & (uint8_t)(1u << bit)) ? 1 : 0;
    s_flags &= (uint8_t)~(1u << bit);
    local_irq_enable();
    return was_set;
}

uint8_t app_defer_is_pending(AppDeferBit_t bit)
{
    if (bit >= APP_DEFER_MAX) {
        return 0;
    }
    return (s_flags & (uint8_t)(1u << bit)) ? 1 : 0;
}

void app_defer_cancel(AppDeferBit_t bit)
{
    if (bit >= APP_DEFER_MAX) {
        return;
    }
    local_irq_disable();
    s_flags &= (uint8_t)~(1u << bit);
    local_irq_enable();
}