C语言通过timeval结构设置周期

#include <stdio.h>
#include <time.h>
#include <windows.h>

int main()
{
int time_interval=3; // Set period to be 3s

printf("Testing start:\n");
while(1){
setPeriod(time_interval);
//You can add a method here to realize what you want to do in this period.
}
return 0;
}

void setPeriod(int time_interval){
static struct timeval tv1;
struct timeval tv2;
int time_in_us;
static int flag = 1;

gettimeofday(&tv2,NULL);

if(flag){
tv1.tv_sec = tv2.tv_sec;
tv1.tv_usec = tv2.tv_usec;
flag = 0;
return;
}

time_in_us = (tv2.tv_sec - tv1.tv_sec) * 1000000 + tv2.tv_usec - tv1.tv_usec;

if(time_in_us >= time_interval * 1000000) {
tv1.tv_sec = tv2.tv_sec;
tv1.tv_usec = tv2.tv_usec;
// You can add a method here to make statistic about the data you get in this peorid.
printf("Hello, world\n");
}
}

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以上代码实现一个周期为3s的设置，执行结果为： 每隔三秒print一个“Hello world”.

注意，要实现每隔三秒print一个“Hello world”， sleep(3000) 会是一个更简便的方法。但是，用sleep方法，那么在该周期三秒内，只能sleep, 不能实现其他动作。

欢迎大家指正！