Re: [PATCH 2/5] refs.c: do not die if locking fails in `write_pseudoref()`

From: Martin Ågren <martin.agren@gmail.com>
Date: May 6, 2018, 15:56 UTC
Message-ID: <CAN0heSpfu+070fxhjjccXQpfFnr13O4tvSaj44YWkFWVJL_4mA@mail.gmail.com>
In-Reply-To: <1525621731.16035.11.camel@novalis.org>

On 6 May 2018 at 17:48, David Turner <novalis@novalis.org> wrote:

> On Sun, 2018-05-06 at 16:10 +0200, Martin Ågren wrote:
>> While at it, make the lock non-static.

Show 10 quoted lines

> Re making the lock static, I wonder about the following case:
>
>       if (read_ref(pseudoref, &actual_old_oid))
>
> die("could not read ref '%s'", pseudoref);
>
> I think this calls exit(), and then atexit tries to clean up the lock
> files.  But since lock is no longer static, the stack may have been
> destroyed (I don't actually know whether this is true, so maybe someone
> else does).

Right. After commit 076aa2cbda (tempfile: auto-allocate tempfiles on heap, 2017-09-05) this is safe though. Quite a few locks have already been moved to the stack, e.g., in 14bca6c63c (sequencer: make lockfiles non-static, 2018-02-27) and 02ae242fdd (checkout-index: simplify locking logic, 2017-10-05). I could add a note to the commit message to make this clear, like "After 076aa2cbda, locks no longer need to be static."

Martin