我需要计算运行某个函数所花费的时间，遇到了下面的代码，以纳秒为单位记录并输出一段代码的执行时间
还有什么区别
struct timeval timer_spent 和 timeval timer_spent
/* Put this line at the top of the file: */
#include <sys/time.h>
/* Put this right before the code you want to time: */
struct timeval timer_start, timer_end;
gettimeofday(&timer_start, NULL);
/* Put this right after the code you want to time: */
gettimeofday(&timer_end, NULL);
double timer_spent = timer_end.tv_sec - timer_start.tv_sec + (timer_end.tv_usec - timer_start.tv_usec);
printf("Time spent: %.6f\n", timer_spent)/1000000.0;
但我需要以纳秒为单位的精确计时。我对 timeval 结构没有完整的想法。
请大家帮帮我.. !!
最佳答案
But I need the precise timing in nanoseconds.
然后使用
int clock_gettime(clockid_t clk_id, struct timespec *tp);
它以秒和纳秒为单位返回时间
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* nanoseconds */
};
有用的链接:
关于c - 时间结构使用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21520206/