随想录（编写用户侧定时器）

来源：互联网发布：oracle 数据导入导出编辑：程序博客网时间：2024/05/29 19:05

定时器是我们在平时开发中经常使用到的工具，特别是在协议的编写上更是必不可少的组成部分。虽然系统本身给我们提供了定时器，但是有的时候，我们也想自己编写一个粗粒度的定时器，比如说在单元测试的时候。大家只要看到下面的实例代码，其实就会发现，只要利用一下sleep函数，编写属于自己的定时器原来不是一件复杂的事情。当然，在实现自己的定时器之前，你需要明白自己的定时器应该设计成什么样子？比如说，

（1）定时器是否需要做互斥处理？

（2）定时器支持那几种类型？

（3）定时器支持的最大粒度是多少？有没有什么限制？

（4）定时器的接口是什么？

（5）定时器怎么遍历、组织和运行？

下面的代码就是我自己练习时编写的一个定时器，具有下面几个特点：

（1）支持1s为基本单位的定时操作；

（2）支持定时器互斥操作，适合移植；

（3）支持单次和循环两种定时器；

（4）tick计数和定时函数处理是由不同线程完成；

（5）定时器接口简单，和linux定时器接口基本一致。

最后贴出自己的定时器代码，欢迎大家多提宝贵意见。

struct TIMER{int type;int state;int count;int expire;void (*func)(void*);void* param;struct LINK_NODE node;char name[MAX_NAME_LEN];};#define MAX_NAME_LEN 16#define TIMER_LOCK_INIT()#define TIMER_LOCK(sem)#define TIMER_UNLOCK(sem)#define STATUS int#define MAX_TIMER_VALUE (7*24*3600)enum{SINGLE_SHOT = 1,RECYCLE_TYPE = 2};enum{TIMER_ACTIVE = 1,TIMER_NOT_ACTIVE = 2};static int g_timer_count;static struct LINK_NODE g_timer_head;static HANDLE h_timer_sem;void timer_init(){g_timer_count = 0;link_init(&g_timer_head);h_timer_sem = TIMER_LOCK_INIT();}STATUS alloc_timer(const char* name, int type, int count, void (*func)(void*), void* param){struct LINK_NODE* p_node;struct TIMER* p_timer;if(NULL == name || NULL == func || NULL == param){return FALSE;}if(strlen(name) >= MAX_NAME_LEN){return FALSE;}if(SINGLE_SHOT != type && RECYCLE_TYPE != type){return FALSE;}if(MAX_TIMER_VALUE < count || 0 == count){return FALSE;}TIMER_LOCK(h_timer_sem);for(p_node = g_timer_head.next; NULL != p_node; p_node = p_node->next){p_timer = GET_DATA_BY_ADDRESS(p_node, struct TIMER, node);if(0 == strncmp(p_timer->name, name, strlen(name))){TIMER_UNLOCK(h_timer_sem);return FALSE;}}p_timer = (struct TIMER*)malloc(sizeof(struct TIMER));if(NULL == p_timer){TIMER_UNLOCK(h_timer_sem);return FALSE;}memset(p_timer, 0, sizeof(struct TIMER));strncpy(p_timer->name, name, strlen(name));p_timer->type = type;p_timer->count = count;p_timer->func = func;p_timer->param = param;p_timer->state = TIMER_NOT_ACTIVE;add_node_into_link(&p_timer->node, &g_timer_head);TIMER_UNLOCK(h_timer_sem);return TRUE;}STATUS timer_start(const char* name){struct LINK_NODE* p_node;struct TIMER* p_timer;if(NULL == name || strlen(name) >= MAX_NAME_LEN){return FALSE;}TIMER_LOCK(h_timer_sem);for(p_node = g_timer_head.next; NULL != p_node; p_node = p_node->next){p_timer = GET_DATA_BY_ADDRESS(p_node, struct TIMER, node);if(0 == strncmp(p_timer->name, name, strlen(name))){break;}}if(NULL == p_node){TIMER_UNLOCK(h_timer_sem);return FALSE;}if(TIMER_NOT_ACTIVE == p_timer->state){p_timer->expire = g_timer_count + p_timer->count;p_timer->state = TIMER_ACTIVE;}TIMER_UNLOCK(h_timer_sem);return TRUE;}STATUS timer_del(const char* name){struct LINK_NODE* p_node;struct TIMER* p_timer;if(NULL == name || strlen(name) >= MAX_NAME_LEN){return FALSE;}TIMER_LOCK(h_timer_sem);for(p_node = g_timer_head.next; NULL != p_node; p_node = p_node->next){p_timer = GET_DATA_BY_ADDRESS(p_node, struct TIMER, node);if(0 == strncmp(p_timer->name, name, strlen(name))){break;}}if(NULL == p_node){TIMER_UNLOCK(h_timer_sem);return FALSE;}delete_node_from_link(&p_timer->node);TIMER_UNLOCK(h_timer_sem);free(p_timer);return TRUE;}void timer_run(){struct LINK_NODE* p_node;struct TIMER* p_timer;int count;while(1){count = g_timer_count;TIMER_LOCK(h_timer_sem);for(p_node = g_timer_head.next; NULL != p_node; p_node = p_node->next){p_timer = GET_DATA_BY_ADDRESS(p_node, struct TIMER, node);if(TIMER_ACTIVE == p_timer->state && count > p_timer->expire){p_timer->func(p_timer->param);if(SINGLE_SHOT == p_timer->type){p_timer->state = TIMER_NOT_ACTIVE;}else{p_timer->expire = count + p_timer->count;}}}TIMER_UNLOCK(h_timer_sem);sleep(1);}}void tick_process(){while(1){g_timer_count ++;sleep(1);}}