profile_timer

This object provides for obtaining run-time information on the program, idealially suited for profiling code and running benchmarks.

The members to control the timer are:

start -- starts the timer.
stop -- stops the timer and makes results available.
snapshot -- makes current time results available, but does not stop timing.
reset -- resets the elapsed times to zero. Does not clear a pending start.

The timing information is thread-specific, and in order to get meaningful results, start and the matching stop must be called from the same thread.

The underlying mechanism is the Win32 call GetThreadTimes, which returns the amount of time spent actually exeuting this thread. Time spent in other threads during time-slicing does not count, and time spent sleeping or blocked does not count.

To obtain results, call

get_user -- time spent in user mode (normal code).
get_kernel -- time spent in kernel mode (device drivers).

The return value of these functions are in milliseconds, although internallay values are kept to higher precision.