软件定时器实现-方法1

本文介绍了软件定时器的一种实现方法，该方法摘自git上面的实现，具体链接忘了。

缺点：使用起来比较复杂, 如果需要再次触发, 需要重新设置。

方法如下：

//multi_timer.c
#include "multi_timer.h"
#include <stdio.h>

/* Timer handle list head. */
static MultiTimer* timerList = NULL;

/* Timer tick */
static PlatformTicksFunction_t platformTicksFunction = NULL;

int MultiTimerInstall(PlatformTicksFunction_t ticksFunc)
{
    platformTicksFunction = ticksFunc;
    return 0;
}

int MultiTimerStart(MultiTimer* timer, uint64_t timing, MultiTimerCallback_t callback, void* userData)
{
    if (!timer || !callback ) {
        return -1;
    }
    MultiTimer** nextTimer = &timerList;
    /* Remove the existing target timer. */
    for (; *nextTimer; nextTimer = &(*nextTimer)->next) {
        if (timer == *nextTimer) {
            *nextTimer = timer->next; /* remove from list */
            break;
        }
    }

    /* Init timer. */
    timer->deadline = platformTicksFunction() + timing;
    timer->callback = callback;
    timer->userData = userData;

    /* Insert timer. */
    for (nextTimer = &timerList;; nextTimer = &(*nextTimer)->next) {
        if (!*nextTimer) {
            timer->next = NULL;
            *nextTimer = timer;
            break;
        }
        if (timer->deadline < (*nextTimer)->deadline) {
            timer->next = *nextTimer;
            *nextTimer = timer;
            break;
        }
    }
    return 0;
}

int MultiTimerStop(MultiTimer* timer)
{
    MultiTimer** nextTimer = &timerList;
    /* Find and remove timer. */
    for (; *nextTimer; nextTimer = &(*nextTimer)->next) {
        MultiTimer* entry = *nextTimer;
        if (entry == timer) {
            *nextTimer = timer->next;
            break;
        }
    }
    return 0;
}

int MultiTimerYield(void)
{
    MultiTimer* entry = timerList;
    for (; entry; entry = entry->next) {
        /* Sorted list, just process with the front part. */
        if (platformTicksFunction() < entry->deadline) {
            return (int)(entry->deadline - platformTicksFunction());
        }
        /* remove expired timer from list */
        timerList = entry->next;

        /* call callback */
        if (entry->callback) {
            entry->callback(entry, entry->userData);
        }
    }
    return 0;
}

 

/*
 * Copyright (c) 2021 0x1abin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef _MULTI_TIMER_H_
#define _MULTI_TIMER_H_

#include <stdint.h>

#ifdef __cplusplus  
extern "C" {  
#endif

typedef uint32_t (*PlatformTicksFunction_t)(void);

typedef struct MultiTimerHandle MultiTimer;

typedef void (*MultiTimerCallback_t)(MultiTimer* timer, void* userData);

struct MultiTimerHandle {
    MultiTimer* next;
    uint64_t deadline;
    MultiTimerCallback_t callback;
    void* userData;
};

/**
 * @brief Platform ticks function.
 *
 * @param ticksFunc ticks function.
 * @return int 0 on success, -1 on error.
 */
int MultiTimerInstall(PlatformTicksFunction_t ticksFunc);

/**
 * @brief Start the timer work, add the handle into work list.
 *
 * @param timer target handle strcut.
 * @param timing Set the start time.
 * @param callback deadline callback.
 * @param userData user data.
 * @return int 0: success, -1: fail.
 */
int MultiTimerStart(MultiTimer* timer, uint64_t timing, MultiTimerCallback_t callback, void* userData);

/**
 * @brief Stop the timer work, remove the handle off work list.
 *
 * @param timer target handle strcut.
 * @return int 0: success, -1: fail.
 */
int MultiTimerStop(MultiTimer* timer);

/**
 * @brief Check the timer expried and call callback.
 *
 * @return int The next timer expires.
 */
int MultiTimerYield(void);

#ifdef __cplusplus
} 
#endif

#endif

//main.c, 用于测试

//消框定时器
static void __app_multi_timer_proc( MultiTimer* timer, void *userData );
#define TIMER_TEST __app_multi_timer_proc
MultiTimer TmTest; 

unsigned char timer_ms=1000;

//获取系统时间1ms
uint32_t PlatformTicksGetFunc(void)

{
　　// struct timespec current_time;
　　// clock_gettime(CLOCK_MONOTONIC, &current_time);
　　// return (uint64_t)((current_time.tv_sec * 1000) + (current_time.tv_nsec / 1000000));
　　return GetSysTick1MsCnt();
}

void __app_multi_timer_proc( MultiTimer* timer, void *userData )

{

　　unsigned int param = (unsigned int )userData;
　　printf( "multi timer :%d\n",param );
   //如果需要轮询执行,需要再次调用MultiTimerStart
   MultiTimerStart( &TmTest, timer_ms, TIMER_TEST, (void *)param )
}

int main()
{
    //初始化软件定时器
    MultiTimerInstall(PlatformTicksGetFunc);
　　
　　unsigned int param = 0;
    //设置一个软件定时器
　　MultiTimerStart( &TmTest, timer_ms, TIMER_TEST, (void *)param )

　　while(1)
　　{
　　　　//软件定时器处理逻辑
       MultiTimerYield();
   }

}