Complete lack of diary entries for the past week demonstrates#

Thu, 13 Dec 2001 18:43:45 +0000

Complete lack of diary entries for the past week demonstrates quite clearly that I've not been on trains much recently.

Sunbury project finished for the year. Lisp web project (the thing I needed UncommonSQL for) also substantially finished and waiting for installation 'at risk' time to be scheduled. Time to do some free software again, and this time it's SBCL PPC.

Convinced myself that the pseudo-atomic mechanism does work after all. Unusually, it uses two registers: ALLOC says whether we're in a PA section, NL3 says whether it was interrupted. At end of PA section, we add NL3 (which is a big number) to ALLOC, then conditionally trap to the run-pending-signal code if ALLOC is big enough to be negative. Don't yet see why we need two registers, though. Don't know what happens if we get a signal in foreign code either, but I doubt that's allowed inside a PA section. NL3 is $6, ALLOC is $17

Which is nice to know, but doesn't get us any closer to solving the actual bug we're currently seeing.