Description
Performing Thread.sleep() with non-rounded values increases the frequency of interrupts on Windows machines; this can cause performance problems, and on some machines even clock drift problems for the duration of the sleep.
Fixing the issue is trivial: lower the degree of randomness by allowing only "rounded" sleep periods.
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6464007
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6435126