A program reads configuration data from a file during startup, and then periodically checks to see

if the configuration file has been changed during execution $($by$,$ for example, human editing it and

then saving it$).$ If the file has been changed, the program is required to load the new configuration

from the updated file and continue with those settings. What considerations need to be taken into

account when implementing such a program? How do these considerations change if other parts of

the program use multiple threads?