c++精确的时间测试

#include 

double getCurrentTime()
{
    struct timeval tv;
    gettimeofday(&tv,NULL);
    return tv.tv_sec * 1000 + (double)(tv.tv_usec) / 1000;
}

int main(){
    double start = getCurrentTime()
    // your program
    double finish = getCurrentTime()
    std::cout << "total time: " << finish -start << "ms" << std::endl;
    return 0;
}