Re: [PATCH] index-pack: spawn threads atomically

[Jeff King <peff@peff.net>]

On Fri, Jan 05, 2024 at 11:33:23AM -0500, Taylor Blau wrote:

> -	test_must_fail git index-pack --fix-thin --stdin <recoverable.pack
> +	test_must_fail git index-pack --threads=1 --fix-thin --stdin <recoverable.pack
> [...]
> For what it's worth, I'm fine with either approach, mostly to avoid
> tying up more of the list's time discussing the options. But I have a
> vague preference towards `--threads=1` since it doesn't require us to
> touch production code.

That's quite tempting, actually. The flip side, though, is that the test
no longer reflects the production code as well. That is, in the real
world we'd still call exit() from a thread. That obviously works OK now
(modulo LSan), but if we ever had a regression where that left us in an
inconsistent state, we'd be less likely to notice it. Feels kind of
unlikely in practice, though.

I dunno. I guess the real least-bad thing is seeing if LSan can be
fixed to handle this atomically. I haven't even reported it there.

If do go with "--threads=1", I suspect several tests in that file need
it.

-Peff