http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46096
--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> 2010-10-20 16:57:45 UTC --- If the value changes because of IO (rather than being set by another thread, as in your testcase) then volatile might be the right option. Condvars could also work and allow you to block, rather than doing a busy wait while holding a lock.
