Linux下测试函数运行时间

添加头文件

#include <time.h>

在测试函数前添加代码

struct timespec time1, time2; 
clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time1);

在函数结尾处添加代码

clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time2); 
printf("ProcessTime:%ld \n", diff(time1, time2).tv_nsec);

diff函数声明

struct timespec diff(struct timespec start, struct timespec end);

diff函数定义

struct timespec diff(struct timespec start, struct timespec end)
{
    struct timespec temp;
    if ((end.tv_nsec - start.tv_nsec) < 0) {
        temp.tv_sec = end.tv_sec - start.tv_sec - 1;
        temp.tv_nsec = 1000000000 + end.tv_nsec - start.tv_nsec;
    }
    else {
        temp.tv_sec = end.tv_sec - start.tv_sec;
        temp.tv_nsec = end.tv_nsec - start.tv_nsec;
    }
    return temp;
}