Re: blead-156-g46807d8 on VMS failures

On Dec 31, 2008, at 7:04 PM, John Malmberg wrote:

> With this build, I am seeing the following failures on VMS:
>
> lib/Thread/Queue/t/02_refs.t is failing on tests 18, 23, 24, and 26

I haven't looked at that one yet.

> The new test lib/autodie/truncate.t fails on test 3 and then hangs  
> until it is killed.
>
> EAGLE> mcr [-]ndbgperl.exe -d "-I../" lib/autodie/truncate.t
>
> Daughter DB session started...
> 1..3
> ok 1 - Truncating STDOUT should throw an exception isa  
> autodie::exception
> ok 2 - Truncating an unopened file is wrong. isa autodie::exception
> not ok 3 - Truncating a normal file should be fine
> #   Failed test 'Truncating a normal file should be fine'
> #   at lib/autodie/truncate.t line 52.
> #          got: 'Can't truncate('VMS::Stdio=GLOB(0x1118210)', '0'):  
> invalid argument at (eval 47)[/PROJECT_ROOT/PERL-BLEAD/lib/Fatal
> .pm:829] line 30
> # '
> #     expected: ''

I've noticed this too but haven't gotten to the bottom of it yet.  The  
code where the hang occurs looks like this:

eval {
     use autodie;
     truncate($tmpfh, 0);
};

is($@, "", "Truncating a normal file should be fine");

The first clue as to what's wrong is that it isn't really a "normal"  
file that we are attempting to truncate -- it is a temp file with the  
delete-on-close bit set.  It was opened by VMS::Stdio::vmssysopen from  
File::Temp.

> The hang appears to be here:
>
> *PERLIO  PerlIOUnix_close   80449  0000000000006B38 00000000000CB1B8
> *PERLIO  PerlIOBase_close   79879  00000000000053DC 00000000000C9A5C
> *PERLIO  PerlIOBuf_close    81783  000000000000984C 00000000000CDECC
> *PERLIO  PerlIO__close      79117  0000000000002B6C 00000000000C71EC
> *PERLIO  Perl_PerlIO_close  79130  0000000000002C14 00000000000C7294
> *DOIO    Perl_io_close      71328  0000000000003824 0000000000127274
> *DOIO    Perl_do_close      71289  00000000000034A0 0000000000126EF0
> *PP_SYS  Perl_pp_close      70940  00000000000021AC 0000000000236ABC
> *DUMP    Perl_runops_debug  81364  00000000000087C4 00000000001B9164
> *PERL    Perl_call_sv       73195  0000000000005B48 00000000000BD478
> *PERL    Perl_call_list     80754  000000000000BF78 00000000000C38A8
> *PERL    perl_destruct      71132  0000000000000F78 00000000000B88A8
>

What's hanging is when the END block in File::Temp tries to clean up  
by closing the file.  There may be a pending write or something.

I think there are really two problems.  There is the hang in  
File::Temp's clean-up code.  We should check to make sure the right  
flavor of flush is getting called for something opened from VMS::Stdio.

Upstream of that is the problem that we cannot call truncate on a  
filehandle opened with VMS::Stdio.  The documentation for VMS::Stdio  
says VMS::Stdio ISA IO::File and you can treat its handles like any  
other Perl filehandles.  So something in the class metadata appears to  
be getting mangled.




________________________________________
Craig A. Berry
mailto:[email protected]

"... getting out of a sonnet is much more
  difficult than getting in."
                  Brad Leithauser