C编写的，高度可移植，软件定时器
通过模拟多个软件定时器来实现硬件的一些功能。
MultiTimer 是一个软件定时器扩展模块，可无限扩展你所需的定时器任务，取代传统的标志位判断方式， 更优雅更便捷地管理程序的时间触发时序。一共有3个文件：
multi_timer.c--定时器c源文件；
multi_timer.h--定时器h头文件；
main--用户代码文件。
1 #include"multi_timer.h" 2 3 struct Timer timer1; 4 5 struct Timer timer2; 6 7 voidtimer1_callback() 8 9 { 10 11 printf( "timer1 timeout!rn"); 12 13 } 14 15 voidtimer2_callback() 16 17 { 18 19 printf( "timer2 timeout!rn"); 20 21 }
1、先申请一个定时器管理handle ``` struct Timer timer1; ``` 2、初始化定时器对象，注册定时器回调处理函数，设置定时时间（ms），循环定时触发时间 ``` timer_init(struct Timer* handle, void(*timeout_cb)(), uint32_t timeout, uint32_t repeat); ``` 3.启动定时器 ``` timer_start(&timer1); ``` 4.设置1ms的硬件定时器循环调用 *timer_ticks()* 以提供时间基准 ``` void HAL_SYSTICK_Callback(void) { timer_ticks(); } ``` 5.在主循环调用定时器后台处理函数 ``` int main() { ... while(1) { ... timer_loop(); } } ```
上面，我们定义了两个定时器，第一个以每1秒一次进行循环执行，第二个定时器50ms之后只执行一次，执行之后，可以通过相应的回调函数打印出来，里面就可以添加我们的定时任务了。
1 /* 2 3 * multi_timer.h 4 5 */ 6 7 #ifndef _MULTI_TIMER_H_ 8 9 #define_MULTI_TIMER_H_ 10 11 #include "stdint.h" 12 13 typedef structTimer { 14 15 uint32_t timeout; 16 17 uint32_t repeat; 18 19 void(*timeout_cb)( void); 20 21 structTimer* next; 22 23 }Timer; 24 25 #ifdef __cplusplus 26 27 extern"C"{ 28 29 #endif 30 31 voidtimer_init(structTimer* handle, void(*timeout_cb)(), uint32_t timeout, uint32_t repeat); 32 33 inttimer_start(structTimer* handle); 34 35 voidtimer_stop(structTimer* handle); 36 37 voidtimer_ticks(void); 38 39 voidtimer_loop(void); 40 41 // void timer_again(struct Timer* handle); 42 43 // void timer_set_repeat(struct Timer* handle, uint32_t repeat); 44 45 #ifdef __cplusplus 46 47 } 48 49 #endif 50 51 #endif 52 53 /* 54 55 * multi_timer.c 56 57 */ 58 59 #include "multi_timer.h" 60 61 //timer handle list head. 62 63 staticstruct Timer* head_handle = NULL; 64 65 //Timer ticks 66 67 staticuint32_t _timer_ticks = 0; 68 69 /** 70 71 * @briefInitializes the timer struct handle. 72 73 * @paramhandle: the timer handle strcut. 74 75 * @paramtimeout_cb: timeout callback. 76 77 * @paramrepeat: repeat interval time. 78 79 * @retvalNone 80 81 */ 82 83 void timer_init(struct Timer* handle, void(*timeout_cb)(), uint32_t timeout, uint32_t repeat) 84 85 { 86 87 // memset(handle, sizeof(struct Timer), 0); 88 89 handle->timeout_cb = timeout_cb; 90 91 handle->timeout = _timer_ticks + timeout; 92 93 handle->repeat = repeat; 94 95 } 96 97 /** 98 99 * @briefStart the timer work, add the handle into work list. 100 101 * @parambtn: target handle strcut. 102 103 * @retval0: succeed. -1: already exist. 104 105 */ 106 107 int timer_start(struct Timer* handle) 108 109 { 110 111 struct Timer* target = head_handle; 112 113 while(target) { 114 115 if(target == handle) return-1; //already exist. 116 117 target = target->next; 118 119 } 120 121 handle->next = head_handle; 122 123 head_handle = handle; 124 125 return0; 126 127 } 128 129 /** 130 131 * @briefStop the timer work, remove the handle off work list. 132 133 * @paramhandle: target handle strcut. 134 135 * @retvalNone 136 137 */ 138 139 void timer_stop(struct Timer* handle) 140 141 { 142 143 struct Timer** curr; 144 145 for(curr = &head_handle; *curr; ) { 146 147 struct Timer* entry = *curr; 148 149 if(entry == handle) { 150 151 *curr = entry->next; 152 153 // free(entry); 154 155 } else 156 157 curr = &entry->next; 158 159 } 160 161 } 162 163 /** 164 165 * @briefmain loop. 166 167 * @paramNone. 168 169 * @retvalNone 170 171 */ 172 173 void timer_loop() 174 175 { 176 177 struct Timer* target; 178 179 for(target=head_handle; target; target=target->next) { 180 181 if(_timer_ticks >= target->timeout) { 182 183 if(target->repeat == 0) { 184 185 timer_stop(target); 186 187 } else{ 188 189 target->timeout = _timer_ticks + target->repeat; 190 191 } 192 193 target->timeout_cb(); 194 195 } 196 197 } 198 199 } 200 201 /** 202 203 * @briefbackground ticks, timer repeat invoking interval 1ms. 204 205 * @paramNone. 206 207 * @retvalNone. 208 209 */ 210 211 void timer_ticks() 212 213 { 214 215 _timer_ticks++; 216 217 }