unning in its pool.  Another approach is to throw an
exception when adding tasks which exceed a user-selectable level.
</p>
<p>The best approach is for user code to provide its own rate limiting in
cases where the way that that code is organised means that it could
produce an excessive number of accumulating unexecuted tasks in the
thread pool, possibly by applying delays when unexecuted tasks rise in
number excessively, using timeouts with an event loop. This may be
checked for by having code call the thre