[PATCH] ruby: make sure the database is closed

[Ali Polatel]

2012/4/24 Felipe Contreras <felipe.contreras at gmail.com>:
> On Tue, Apr 24, 2012 at 4:15 AM, Austin Clements <amdragon at mit.edu> wrote:
>> Quoth Felipe Contreras on Apr 24 at  3:45 am:
>>> On Tue, Apr 24, 2012 at 2:46 AM, Ali Polatel <alip at exherbo.org> wrote:
>>> > 2012/4/24 Felipe Contreras <felipe.contreras at gmail.com>:
>>>
>>> >> Personally I don't see why an object, like say a query would remain
>>> >> working correctly after the database is gone, either by calling
>>> >> .close() directly, or just loosing the pointer to the original object.
>>> >> I don't think users would expect that, or, even if they somehow found
>>> >> it useful, that most likely would be very seldom, and hardly worth
>>> >> worrying about it.
>>> >
>>> > Working correctly is not expected but wouldn't it be more appropriate
>>> > to throw an exception rather than dumping core or printing on standard error?
>>>
>>> Sure, if that was possible.
>>>
>>> > I wonder whether we can make both work somehow.
>>> > Maybe by using talloc explicitly and keeping reference pointers?
>>> > I don't know whether it's worth bothering.
>>>
>>> Maybe, I don't see how, that's just not how C works. Maybe talloc does
>>> have some way to figure out if a pointer has been freed, but I doubt
>>> that, and I can't find it by grepping through the API.
>>>
>>> Another option would be hook into talloc's destructor so we know when
>>> an object is freed and taint it, but then we would be overriding
>>> notmuch's destructor, and there's no way around that (unless we tap
>>> into talloc's internal structures). A way to workaround that would be
>>> to modify notmuch's API so that we can specify a destructor for
>>> notmuch objects, but that would be tedious, and I doubt a lof people
>>> beside us would benefit from that.
>>
>> I believe (though I might be wrong) that bindings could simply
>> maintain their own talloc references to C objects returned by
>> libnotmuch to prevent them from being freed until the wrapper object
>> is garbage collected.  This would require modifying all of the
>> library's _destroy functions to use talloc_find_parent_bytype and
>> talloc_unlink instead of simply calling talloc_free, but I don't think
>> this change would be particularly invasive and it certainly wouldn't
>> affect the library interface.
>
> That might work, but still, I don't see why this patch can't be applied.

I don't have anything against applying this patch.
If this fix has a kind of urgency -and I doubt it does- please get
someone to push the patch.
Below is my confirmation to accept the consequences:
LGTM

Otherwise, I'd rather we fix it properly most probably using the
method described in Austin's previous mail.

> Cheers.
>
> --
> Felipe Contreras

        -alip