[Xapian-devel] Problems with /bin/cat and flintlock?

[Samuel Williams]

Dear Olly,

I would like to help and this test case looks good, I tried to build Xapian from source code on a Mac but had some problems. I will try again and see if I can reproduce the bug.

In my case, I've certainly noticed that the bug is intermittent, it doesn't always lock up passenger - maybe it is something to do with trying to create multiple instances of WritableDatabase in different processes? I will do further investigation.

Using SIGKILL will definitely do the trick, but it does feel to me to be heavy handed - on the other hand, it might also be the correct approach because if for some reason, the child process gets stuck, no amount of SIGHUP is going to help. Well, I've seen OS bugs where even SIGKILL doesn't work but obviously that isn't something we need to be concerned with hopefully.

So:
(1) I can spend some time trying to figure out if that test case reproduces the bug
OR
(2) We can change to SIGKILL and be done with it.

Well, I'd like to have a solid test case first, so I'd go for (1), but also my time is limited, which means that to fix the problem soon (2) is the best approach. What do you think?

Thanks for writing a test case.

Kind regards,
Samuel

On 14/05/2011, at 4:52 PM, Olly Betts wrote:

> On Fri, Apr 29, 2011 at 08:42:11PM +1200, Samuel Williams wrote:
>> I made a patch:
>> 
>> https://github.com/ioquatix/xapian/commit/cc49918129acf1991dd1b672a26bb8c625d40111
>> 
>> It needs to be tested, I will try testing it, but it might be good to
>> do a point release soon with this amendment. I will try to test in my
>> environment.
> 
> Thanks.  I think I prefer switching to SIGKILL (which can't be caught or
> ignored) rather than trying to ensure SIGHUP isn't ignored.  It just
> seems the simpler fix.
> 
> But I'm failing to reproduce the hang currently - this is my attempt at
> a testcase - does it fail for you if you remove your fix?
> 
> http://oligarchy.co.uk/xapian/patches/xapian-ignoresighup1-testcase.patch
> 
> Cheers,
>    Olly