What is the purpose of QueryPerformanceCounter in C++?

In C++, the QueryPerformanceCounter function is used to obtain the value of a high-precision performance counter. It is commonly used for measuring code execution time and performance analysis.

The QueryPerformanceCounter function returns the value of the current system’s performance counter in basic counting units. By obtaining the values of the performance counter twice, the time interval between the two calls can be calculated, allowing for the measurement of code execution time.

Compared to other timing functions like clock() or GetTickCount(), the QueryPerformanceCounter() function offers greater precision and accuracy. It is suitable for situations that require very precise timing, such as performance testing, algorithm optimization, and real-time system development.

To use the QueryPerformanceCounter function, you need to combine it with the QueryPerformanceFrequency function to obtain the frequency of the performance counter, which is the number of counts per second. By calculating the difference in counts between two consecutive calls and dividing by the frequency, you can determine the time interval in seconds.

In conclusion, the purpose of the QueryPerformanceCounter function in C++ is to provide high-precision timing capabilities for measuring code execution time and performance analysis.