Timing the execution of functions with std::chrono

20 Oct 2023

tech

When developing software, it is often necessary to measure the execution time of certain functions or code snippets. This can help identify bottlenecks and improve the overall performance of the application. In C++, you can easily accomplish this using the std::chrono library.

To measure the execution time of a function, follow these steps:

Import the necessary headers:
```
#include <iostream>
#include <chrono>
```

Define a function that you want to time. For example:

void myFunction()
{
 // Code to be timed
 // ...
}

Create variables to store the start and end time points:
```
std::chrono::steady_clock::time_point start, end;
```
Before calling the function, set the start time point:
```
start = std::chrono::steady_clock::now();
```
Call the function you want to time:
```
myFunction();
```
After the function has executed, set the end time point:
```
end = std::chrono::steady_clock::now();
```

Calculate the duration by subtracting the start time from the end time:

auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start).count();

Print the duration to the console:

std::cout << "Execution time: " << duration << " microseconds" << std::endl;

That’s it! Now, when you run your program, you will see the execution time of your function. Remember to include the <chrono> header and use the std::chrono::steady_clock class for accurate timing.

It’s important to note that the duration provided by std::chrono is implementation-defined. Therefore, it may vary depending on the platform and system you are using. However, it is still a valuable tool for comparing and optimizing different parts of your code.

Using std::chrono to time functions is a simple and effective way to measure the performance of your code. With this information, you can identify and address any performance bottlenecks, leading to faster and more efficient software.

For more information, refer to the C++ Reference on std::chrono and its related classes.

#tech #C++