Sets 'tv' to the current time (as returned by gettimeofday()),
looking at the cached value in 'base' if possible, and calling
gettimeofday() or clock_gettime() as appropriate if there is no
cached time.
Generally, this value will only be cached while actually
processing event callbacks, and may be very inaccuate if your
callbacks take a long time to execute.
Sets 'tv' to the current time (as returned by gettimeofday()), looking at the cached value in 'base' if possible, and calling gettimeofday() or clock_gettime() as appropriate if there is no cached time.
Generally, this value will only be cached while actually processing event callbacks, and may be very inaccuate if your callbacks take a long time to execute.
Returns 0 on success, negative on failure.