f a collection is in progress, the pure
spinning stage is skipped.  This has the advantage that uncontested and
thus most uniprocessor lock acquisitions are very cheap.  It has the
disadvantage that the application may sleep for small periods of time
even when there is work to be done.  And threads may be unnecessarily
woken up for short periods.  Nonetheless, this scheme empirically
outperforms native queue-based mutual exclusion implementations in most
cases, sometimes drastically so.
<H2>Options for enha