🚀 go-pugleaf

I'm creating a memory hungry GEM application and I would like to create a
memory bar chart on the screen.  One way I've thought of to do this is
to call Malloc(-1L) at program startup to get the total available space,
then call it during program operation (at appropriate times) to find
current available space.  Then space_used = total - current_available

Questions:

1) Is there a better way?

2) Would you do this in an event loop?  How would you control it?
   I.e if (memory_bar_is_not_covered_by_a_window
       && memory_using_event_has_occured)
           update_memory_bar(Malloc(-1));


Thanks for any help!

-Joe Gilray