ompgetwtime

ompgetwtime is a function used in OpenMP to retrieve the current value of the high-resolution timer. OpenMP is an API that supports shared-memory multiprocessing programming in C, C++, and Fortran. The timer provided by ompgetwtime is intended for measuring elapsed time for performance profiling and benchmarking. It typically returns a double-precision floating-point number representing the elapsed time in seconds since some arbitrary starting point.

The specific resolution and accuracy of the timer are system-dependent, but it is generally designed to be finer than typical system clock functions. This makes it suitable for timing short code segments. It is important to note that the starting point for the timer is not guaranteed to be consistent across different program executions or even across different threads within the same execution. Therefore, ompgetwtime is best used for measuring the duration between two calls within the same execution context, rather than for absolute timekeeping.

When using ompgetwtime, one common pattern is to record the start time before a section of code, then record the end time after that section, and finally calculate the difference to obtain the elapsed time. This function is part of the OpenMP runtime library and is available when OpenMP is enabled during compilation.