#include <stdio.h> 
#include <sys/time.h> 
#include <time.h> 

int gettimeofday(struct timeval *tv, struct timezone *tz); 

int main(int argc,char * argv[]){ 

struct timeval t_start,t_end; 

long cost_time = 0; 

//get start time 
gettimeofday(&t_start, NULL); 
long start = ((long)t_start.tv_sec)*1000+(long)t_start.tv_usec/1000; 
printf("Start time: %ld ms\n", start); 

sleep(2); 
usleep(5000);//5毫秒
//get end time 
gettimeofday(&t_end, NULL); 
long end = ((long)t_end.tv_sec)*1000+(long)t_end.tv_usec/1000; 
printf("End time: %ld ms\n", end); 

//calculate time slot 
cost_time = end - start; 
printf("Cost time: %ld ms\n", cost_time); 

return 0; 

}