Non-reentrant libmpeg2 initialisation

As of 00d1f50e, libmpeg2 is calling signal() and using a static jump buffer every time the plugin is started. This is obviously not thread-safe / not re-entrant.

changed milestone to %4.0

added Component::Decoders label

assigned to @jnqnfe

Looks like signal() is used only on PPC and SPARC ?

Yes, actually it's not a regression.

removed milestone %4.0

changed title from 4.0 regression: non-reentrant libmpeg2 initialisation to Non-reentrant libmpeg2 initialisation

Yes, the bits involving signal() are indeed only used for PPC & Sparc. I wasn't sure how much relevance those platforms still held; noticed that we were using it already for Sparc, and noticed that we have our own similar signal() based detection for altivec and SSE(1), so I did not end up looking too closely at those bits. I've thus failed to notice the important safety difference between our signal() based implementation and theirs.

So yes, we do have an unintended regression for PPC, sorry.

I'm not sure if we care about PPC any more, but I'll make an MR to fix it.

Do we care about supporting Sparc?

mentioned in merge request !466 (merged)

unassigned @jnqnfe

closed with commit 9fdfdd30