Bernie Wieser

So far, I am having fun replicating the issue. I've rebuilt a tiny version without optimization and full symbolics. This build does not crash - at least it ran 3...

I found the bug. The pointers to the buffers were going invalid thanks to optimization. I fixed the bug. Anything const dynamic should be validated before use. This only appears...

This is not an osd sdl issue. The code is not thread safe "enough". https://github.com/mamedev/mame/blame/0636e54bb60192652efeeeb7732103b9134a31eb/src/devices/sound/discrete.cpp#L246 Sending a patch.

Patch sent, explanation of why I treat process as "critical section" https://www.octavianit.com/2024/02/fixing-galaxian-sound-on-arm-8-core.html

Not sure why you reopened it; acquire instead of release appears to have fixed the issue. But *thanks* for your insight.