Perl sleep on windows in a VM or 100% CPU usage or C debugger breakpoints, or bad driver that likes lock all the CPUs and then spin sleep for too long to freeze the PC can cause an overflow in Perl's sleep, and then only a random Windows message (mouse move, repaint, idk what else, but there WILL
be one, thx MS) will breakout of the sleep hang, see https://rt.perl.org/rt3/Ticket/Display.html?id=33096
causing the sleep to take more seconds than it should have. win32/win32.c#l2163 in perl.git
for the offending code.