软件定时器算法-白红宇

软件定时器算法

阅读量：6823 次

发布时间：2019-06-26

本文共 3644 字，大约阅读时间需要 12 分钟。

说明：软件定时器不是定时器，是应用于操作系统中的一种定时回调功能函数的算法。算法结构：本软件定时器，包含一个链表，一个定时器任务。 void updateSystemTime(void)函数要在定时器溢出中断中被调用。

timer_callback.h头文件

#ifndef _TIMER_CALLBACK_H_#define _TIMER_CALLBACK_H_#include "board.h"#define LIST_OK 0#define ERR_LIST_EMPTY 1#define ONLY_ONE 0extern u32 system_time;#define	GET_TICK(tick)	\	do {		\		tick = system_time;	\	} while (tick != system_time)	//#define NULL 0typedef struct{  u32 tick_temp;  u32 tick_begin;}TICK;                  typedef void (*timer_callback_function)(void*);typedef struct callback_timer_type{        unsigned char timer_index;	unsigned char mode;	unsigned long long time;	unsigned long long start_time;	timer_callback_function func;}callback_timer;typedef callback_timer DataType;typedef struct node_l{	DataType data_t;	struct node_l *next_node;}nodelist;void node_test(void );void createNodeList(void);void addNode(nodelist* L);u8 rmNode(nodelist* L);int getNodeNum(void);void timer_task(void);void callback_TimerInit(void );u32 getSystemTime(void);void updateSystemTime(void);#endif

timer_callback.c源文件

#include "timer_callback.h"#include "stdlib.h"//#include "string.h"#include "stdio.h"#include "board.h"/*定义一个链表头指针*/nodelist *nl;/*系统时间,单位ms*/u32 system_time=0;void createNodeList(){    nl = NULL;}void addNode(nodelist* L){	nodelist* tp;	tp = nl;    if(nl==NULL)    {        nl=(nodelist*)malloc(sizeof(nodelist));        *nl=*L;        nl->next_node=NULL;        return;    }	while(tp->next_node!=NULL)    {        tp=tp->next_node;    }    tp->next_node=(nodelist*)malloc(sizeof(nodelist));    *(tp->next_node)=*L;    tp->next_node->next_node=NULL;}u8 rmNode(nodelist* L){  nodelist *tp,*tp_head;  tp = nl;  while(tp!=NULL)  {    if(tp==nl)    {      /*根据索引号删除*/      if(nl->data_t.timer_index==L->data_t.timer_index)      {        nl=nl->next_node;        free(tp);        tp=nl;      }      else      {        tp_head=nl;      }    }    else    {      /*根据索引号删除*/      if(tp->data_t.timer_index==L->data_t.timer_index)      {        tp_head->next_node=tp->next_node;        free(tp);        tp=tp_head->next_node;      }      else      {        tp_head=tp;        tp=tp->next_node;      }    }  }  return LIST_OK;}int getNodeNum(){    int num=0;    nodelist* tp;    tp=nl;    while(tp!=NULL)    {        num++;        tp=tp->next_node;    }    return num;}void timer_task(){    nodelist* tp;	nodelist* rm_temp;    tp=nl;    if(nl!=NULL)    {        if((nl->data_t.time)<(system_time-nl->data_t.start_time))        {            (nl->data_t.func)(NULL);            if(nl->data_t.mode==ONLY_ONE)            {					/*记录要删除节点*/					rm_temp=nl;										nl=nl->next_node;					/*删除节点*/					free(rm_temp);            }            else            {                nl->data_t.start_time=system_time;            }        }    }    else    {        return;    }    while(tp->next_node!=NULL)    {        if((tp->next_node->data_t.time)<(system_time-tp->next_node->data_t.start_time))        {            (tp->next_node->data_t.func)(NULL);            if(tp->next_node->data_t.mode==ONLY_ONE)            {            	  /*记录要删除节点*/				  rm_temp=tp->next_node;                tp->next_node=tp->next_node->next_node;		     	  /*删除节点*/				  free(rm_temp);										                if(tp->next_node==NULL)                {                    return;                }            }            else            {                tp->next_node->data_t.start_time=system_time;            }        }        tp=tp->next_node;    }}void callback_TimerInit(){  //timer4Init();}u32 getSystemTime(void){  return system_time;}void updateSystemTime(void){  system_time++;}

转载于:https://my.oschina.net/u/2345008/blog/892806

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