For details see:
Hans-J. Boehm, "An Almost Non-Blocking Stack", PODC 2004,
-http://portal.acm.org/citation.cfm?doid=1011767.1011774, or
-http://www.hpl.hp.com/techreports/2004/HPL-2004-105.html
+http://portal.acm.org/citation.cfm?doid=1011767.1011774
(This is not exactly the implementation described there, since the
interface was cleaned up in the interim. But it should perform
very similarly.)