From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 12 Jul 2017 16:46:25 GMT
Subject: Re: [PATCH] gc: run pre-detach operations under lock
Message-ID: <xmqqvamx1u3i.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170711090635.swowex7yry7kqb7v@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Instead, we can do something a bit simpler: take the lock
> only for the duration of the pre-detach work, then detach,
> then take it again for the post-detach work. Technically,
> this means that the post-detach lock could lose to another
> process doing pre-detach work. But in the long run this
> works out.

You might have found this part gross, but I actually don't.  It
looks like a reasonable practical compromise, and I tried to think
of a scenario that this would do a wrong thing but I didn't---it is
not like we carry information off-disk from the pre-detach to
post-detach work to cause the latter make decisions on it, so this
"split into two phrases" looks fairly safe.