1. [primarily used by C/Unix programmers, but spreading] It is
received wisdom that in most programs, less than 10% of the code eats
90% of the execution time; if one were to graph instruction visits
versus code addresses, one would typically see a few huge spikes
amidst a lot of low-level noise. Such spikes are called hot spots and
are good candidates for heavy optimization or {hand-hacking}. The
term is especially used of tight loops and recursions in the code's
central algorithm, as opposed to (say) initial set-up costs or large
but infrequent I/O operations. See {tune}, {hand-hacking}.
2. The active location of a cursor on a bit-map display. "Put the
mouse's hot spot on the `ON' widget and click the left button."
3. A screen region that is sensitive to mouse gestures, which trigger
some action. World Wide Web pages now provide the {canonical}
examples; WWW browsers present hypertext links as hot spots which,
when clicked on, point the browser at another document (these are
specifically called {hotlink}s).
4. In a massively parallel computer with shared memory, the one
location that all 10,000 processors are trying to read or write at
once (perhaps because they are all doing a {busy-wait} on the same
lock).
5. More generally, any place in a hardware design that turns into a
performance bottleneck due to resource contention.
[glossary]
[Reference(s) to this entry by made by: {hand-hacking}{hotlink}{profile}{tune}]