Modify getMyIP to cache the local machine's IP address, and
return it without further accessing of the underlying resolver
libraries during subsequent invocations.
getMyIP is called roughly once a second from within monitor_loop
when refreshing CPU utilization in the bottom-right corner of
the GUI window. Other, dedicated CPU usage windows might also
call getMyIP at regular intervals.
With systemd commit cda458a54 (between v232 and v233), the
implementation of gethostbyname4_r() was updated to a more
intransigently standard-compliant error reporting convention,
which in turn causes glibc to retry in a more labor intensive
way (see https://github.com/systemd/systemd/pull/5359).
Under certain circumstances depending on the local hostname
and IP configuration, the glibc/systemd back-end resolver
routines triggered by getMyIP's call to [socket ...] and
[fconfigure ...] end up taking long enough to noticeably slow
down refreshing the main core-gui window, to the point where
interaction with the GUI becomes difficult.
Signed-off-by: Gabriel Somlo <glsomlo@cert.org>
