Re: svn commit: r1676417 - /perl/modperl/trunk/src/modules/perl/modperl_interp.c

On 05/14/2015 11:24 AM, Niko Tyni wrote:
> On Sun, May 10, 2015 at 01:47:19PM +0100, Steve Hay wrote:
>> On 28 April 2015 at 07:51,  <[email protected]> wrote:
>>> Author: jkaluza
>>> Date: Tue Apr 28 06:51:12 2015
>>> New Revision: 1676417
>>>
>>> URL: http://svn.apache.org/r1676417
>>> Log:
>>> Initialize interp->refcnt to 1 in modperl_interp_select.
>
>> I cannot understand why, but since this patch was applied I find that
>> t\modules\proxy.t fails every time when I run the full "nmake test",
>> but it always succeeds when I run it in isolation so I'm at a loss to
>> find out what is going wrong. All other tests (apart from those known
>> Win32-specific failures documented in README) still pass. Reverting
>> the patch "fixes" the proxy.t problem, but probably isn't the right
>> solution.

It's caused by Perl_croak/modperl_croak.

Lets take modperl_run_filter as an example. When following code-path is 
executed ...

                 modperl_croak(aTHX_ MODPERL_FILTER_ERROR,
                               "a filter calling $f->read "
                               "must return OK and not DECLINED");

... the MP_INTERP_PUTBACK is not reached for some reason (I presume it's 
because of Perl_croak, but I don't understand why it stops the execution 
of the rest of modperl_run_filter method).

Because of that, the interp->refcnt is not decreased, and the interp is 
not freed.

I has been able to "fix" it by attached patch, but I would like to 
discuss more generic way how to fix that problem...

Any ideas?

Regards,
Jan Kaluza

> As a data point, this also seems to happen with 2.0.9-RC1 on Debian
> kfreebsd-amd64.
>
>    https://buildd.debian.org/status/fetch.php?pkg=libapache2-mod-perl2&arch=kfreebsd-amd64&ver=2.0.9~rc1-1&stamp=1431587841
>
>    request has failed (the response code was: 502)
>    see t/logs/error_log for more details
>    t/modules/proxy.t .......................
>    # connecting to http://localhost:8538/TestModules__proxy
>    1..1
>    # Running under perl version 5.020002 for gnukfreebsd
>    # Current time local: Thu May 14 07:15:21 2015
>    # Current time GMT:   Thu May 14 07:15:21 2015
>    # Using Test.pm version 1.26
>    # Using Apache/Test.pm version 1.39
>    Dubious, test returned 2 (wstat 512, 0x200)
>    Failed 1/1 subtests
>
> I haven't been able to test yet whether it's reproducible there.
>


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Index: src/modules/perl/modperl_filter.c
===================================================================
--- src/modules/perl/modperl_filter.c	(revision 1679170)
+++ src/modules/perl/modperl_filter.c	(working copy)
@@ -535,6 +535,7 @@
                  * pass the bucket brigade through after it called
                  * $f->read(), since it causes a pre-fetch of the
                  * bb */
+                interp->refcnt--;
                 modperl_croak(aTHX_ MODPERL_FILTER_ERROR,
                               "a filter calling $f->read "
                               "must return OK and not DECLINED");