测量C ++中函数调用的执行时间

Question

How can I measure the execution time of a line of code in C++ in Windows . I am inserting about 1,00,000 records boost::multi_index_container as follows:

while(...) //read a single record from a csv file until EOF
{
    ...
    while(...) // split the record into components based on delimiter
    {
        ...
    }
    //insert into boost::multi_index_container
} 

I need to find the time required to insert all the records, but without the execution time of loops. Starting a timer or anything just before insert function and calculating the elapsed time just after the function call gives 0 nanoseconds as the result. So I cannot calculate the time by summing up the individual times. What is the solution?

Answer 1

在Windows上，您可以使用QueryPerformanceCounter获得准确的测量结果。

Answer 2

possible duplicate of How to calculate a time difference in C++ . There are many ways to do this. One that I like uses chrono.

   #include <iostream>
   #include <chrono>

   using namespace std;
   using namespace std::chrono;



   int main()
  {
    high_resolution_clock::time_point t1 = high_resolution_clock::now();
    //your code here
    high_resolution_clock::time_point t2 = high_resolution_clock::now();

    auto duration = duration_cast<microseconds>( t2 - t1 ).count();

    cout << duration;
    return 0;
  }