If @timer has been started but not stopped, obtains the time since
the timer was started. If @timer has been stopped, obtains the
elapsed time between the time it was started and the time it was
stopped. The return value is the number of seconds elapsed,
including any fractional part. The @microseconds out parameter is
essentially useless.
return location for the fractional part of seconds
elapsed, in microseconds (that is, the total number
of microseconds elapsed, modulo 1000000), or %NULL
If @timer has been started but not stopped, obtains the time since the timer was started. If @timer has been stopped, obtains the elapsed time between the time it was started and the time it was stopped. The return value is the number of seconds elapsed, including any fractional part. The @microseconds out parameter is essentially useless.