On Fri, Oct 17, 2008 at 02:33:00PM -0400, Paul Coccoli wrote: > There's no chance that a compiler optimization is hiding the bug, > because we haven't turned on optimization. But there is nothing that stops the compiler from writing read_ptr any number of times it wants unless you make that variable volatile. > HOWEVER, if you go back > to the original version and REMOVE the volatile qualifiers, then > re-compile with -O2, NOW a compiler optimization is hiding the bug > (and the test passes)! The rb->read_ptr is presumably cached in a > register and hence only modified once (giving the same affect as the > patch). Indeed. The original version really invited the problem, by *forcing* the compiler to write read_ptr twice. Ciao, -- FA Laboratorio di Acustica ed Elettroacustica Parma, Italia Lascia la spina, cogli la rosa. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
