In trying to fix this, I think I might have also fixed 3 problems with
different recently failing tests on VMS. But I don't understand why.
I have questions at the end, but the story in the middle is probably necessary.
On Wed, Aug 07, 2013 at 06:20:00PM +0200, H.Merijn Brand wrote:
> Automated smoke report for branch blead 5.19.3 patch
> 6a9ebaf3683d6b0799ce26b5b512469b9c2384d5 v5.19.2-294-g6a9ebaf
> i3: PPC_POWER5 (PPC/1 cpu)
> on AIX - 5.3.0.0/ML12
> Failures: (common-args) -Dcc=gcc
> [stdio]
> ../t/op/fork.t..............................................FAILED
> 7
git bisect reveals that this started failing on AIX with this commit:
commit 684b0ecaad281760b04dd2da317ee0459cafebf6
Author: Tony Cook <t...@develop-help.com>
Date: Tue Jul 16 14:57:20 2013 +1000
[perl #116190] feed an empty stdin to run_multiple_progs() programs
Two tests for -a were attempting to read stdin and blocking with the -a
implies -n change.
diff --git a/t/test.pl b/t/test.pl
index 41efbb8..eb4f868 100644
--- a/t/test.pl
+++ b/t/test.pl
@@ -1134,7 +1134,8 @@ sub run_multiple_progs {
print $fh "\n#line 1\n"; # So the line numbers don't get messed up.
print $fh $prog,"\n";
close $fh or die "Cannot close $tmpfile: $!";
- my $results = runperl( stderr => 1, progfile => $tmpfile, $up
+ my $results = runperl( stderr => 1, progfile => $tmpfile,
+ stdin => '', $up
? (switches => ["-I$up/lib", $switch], nolib =>
1)
: (switches => [$switch])
);
What that commit does is change the generated backtick command from
`./perl -Ilib -e ...`
to
`./perl -e "print qq()" | ./perl -Ilib -e ...`
so that stdin is at EOF.
It turns out that this causes fun on AIX with two tests, because on AIX
/bin/sh is actually ksh, and ksh does pipes differently (with one less
process). With sh, for the latter command line the sh process forks two
children, which use exec to start the two perl processes. The parent shell
process persists for the duration of the pipeline, and the second perl
process starts with no children. With ksh (and zsh), the shell saves a
process by forking a child for just the first perl process, and execing
itself to start the second. This means that the second perl process starts
with one child which it didn't create. This breaks the tests assume that
wait (or waitpid) will only return information about processes started
within the test. One can replicate this is on Linux:
$ sh -c 'pstree -p $$ | cat'
sh(13261)-+-cat(13263)
`-pstree(13262)
$ ksh -c 'pstree -p $$ | cat'
cat(13349)---pstree(13350)
I thought about fixing the tests to make them immune to unexpected extra
child processes, but then realised that it was probably easier to change the
generated backtick command to be
`./perl </dev/null -Ilib -e ...`
I wasn't sure whether this would work on VMS, so I tested it there. I ran
the tests before making that change, and t/lib/croak.t, lib/charnames.t and
lib/warnings.t failed. These failures are new. The failures all look like
this:
$ @[.vms]test .EXE "" "-v" "[.lib]croak.t"
%DELETE-I-FILDEL, PTAC$DKA0:[NCLARK.I.perl-7d9633e5aba8.t]Perl.EXE;1 deleted (16
blocks)
%COPY-S-COPIED, PTAC$DKA0:[NCLARK.I.perl-7d9633e5aba8]PERL.EXE;1 copied to PTAC$
DKA0:[NCLARK.I.perl-7d9633e5aba8.t]Perl.EXE;1 (16 blocks)
%DELETE-I-FILDEL, PTAC$DKA0:[NCLARK.I.perl-7d9633e5aba8.t]vmspipe.com;1 deleted
(16 blocks)
%COPY-S-COPIED, PTAC$DKA0:[NCLARK.I.perl-7d9633e5aba8]vmspipe.com;1 copied to PT
AC$DKA0:[NCLARK.I.perl-7d9633e5aba8.t]vmspipe.com;1 (2 blocks)
7-AUG-2013 21:00:37.83 User: NCLARK Process ID: 20A3A4EB
Node: PTAC Process name: "_FTA275:"
Accounting information:
Buffered I/O count: 1289345 Peak working set size: 31056
Direct I/O count: 1685993 Peak virtual size: 224288
Page faults: 1735001 Mounted volumes: 0
Images activated: 4216
Elapsed CPU time: 0 00:07:36.58
Connect time: 48 19:31:58.07
1..37
# From PTAC$DKA0:[NCLARK.I.perl-7d9633e5aba8.t.lib.croak]mg.
PROG:
# mg.c
$SIG{_HUNGRY} = \&mmm_pie;
warn "Mmm, pie";
EXPECTED:
No such hook: _HUNGRY at - line 2.
EXIT STATUS: != 0
GOT:
No such hook: _HUNGRY at - line 2.
EXIT STATUS: 0
not ok 1 - Perl_magic_setsig
t/[.lib]croak ... FAILED at test 1
Failed 1 test out of 1, 0.00% okay.
[.lib]croak.t
### Since not all tests were successful, you may want to run some of
### them individually and examine any diagnostic messages they produce.
### See the INSTALL document's section on "make test".
u=456.66 s=0.00 cu=0.00 cs=0.00 scripts=1 tests=37
7-AUG-2013 21:01:21.01 User: NCLARK Process ID: 20A3A4EB
Node: PTAC Process name: "_FTA275:"
Accounting information:
Buffered I/O count: 1290342 Peak working set size: 31056
Direct I/O count: 1686033 Peak virtual size: 224288
Page faults: 1735612 Mounted volumes: 0
Images activated: 4218
Elapsed CPU time: 0 00:07:36.68
Connect time: 48 19:32:41.25
%SYSTEM-F-ABORT, abort
Note
1) All three fail on the first program which has an expected nonzero
EXIT STATUS
2) For all three, the test script aborts at that point
When I change t/test.pl to use the generated backticks redirecting from
/dev/null instead of using a pipeline, all 3 pass again.
(This is currently on smoke-me/nicholas/runperl-empty-STDIN and I will merge
it to blead when results come in for Win32 and a couple of other systems)
Questions
1) Why does using a pipeline in backticks change the exit status?
2) Why does runperl() in t/test.pl abort on VMS if exit status is wrong?
(or is it vmspipe.com aborting?)
*nix doesn't abort on the first test, and I don't think that Win32 does
either.
Nicholas Clark
