Recursion memory leak when assignment in if condition

[p5pRT]

Migrated from rt.perl.org#57174 (status was 'open')

Searchable as RT57174$

[p5pRT]

From Thushan.Abeysekera@computershare.com

Category​: core

Severity​: medium

Originally observed in​: perl\, v5.8.6 built for MSWin32-x86-multi-thread

This problem can be replicated in perl 5.10.0 i686-linux-thread-multi.

Please check http​://www.perlmonks.org/?node_id=698735 for a discussion on this.

Thanks\,

Thushan Abeysekera

Programmer Analyst

Computershare

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[p5pRT]

From Thushan.Abeysekera@computershare.com

Created by thushan.abeysekera@computershare.com

This is a bug report for perl from thushan.abeysekera@​computershare.com\, generated with the help of perlbug 1.35 running under perl v5.8.6.

----------------------------------------------------------------- There seems to be a memory leak when doing recursion with goto &sub_name syntax. Run following two endless loops and check memory usage. While script 1 runs out of memory\, script 2 runs without a problem.

Script 1 (This has the memory leak)​:

use strict; test1();

sub test1 {   my $v=0;   if ($v = get_true()) {   goto &test1;   } }

sub get_true {   return 1; }

Script 2 (This runs without a problem)​:

use strict; test1();

sub test1 {   my $v=0;   $v = get_true();   if ($v) {   goto &test1;   } }

sub get_true {   return 1; }

Originally observed in​: perl\, v5.8.6 built for MSWin32-x86-multi-thread

This problem can be replicated in perl 5.10.0 i686-linux-thread-multi.

Please check http​://www.perlmonks.org/?node_id=698735 for a discussion on this.

Perl Info

``` --- Flags: category=core severity=medium --- Site configuration information for perl v5.8.6: Configured by ActiveState at Mon Dec 13 09:51:32 2004. Summary of my perl5 (revision 5 version 8 subversion 6) configuration: Platform: osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread uname='' config_args='undef' hint=recommended, useposix=true, d_sigaction=undef usethreads=define use5005threads=undef useithreads=define usemultiplicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cl', ccflags ='-nologo -Gf -W3 -MD -Zi -DNDEBUG -O1 -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX', optimize='-MD -Zi -DNDEBUG -O1', cppflags='-DWIN32' ccversion='', gccversion='', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64', lseeksize=8 alignbytes=8, prototype=define Linker and Libraries: ld='link', ldflags ='-nologo -nodefaultlib -debug -opt:ref,icf -libpath:"C:\Perl586\lib\CORE" -machine:x86' libpth=\lib libs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib perllibs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib uuid.lib ws2_32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl58.lib gnulibc_version='undef' Dynamic Linking: dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' ' cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -debug -opt:ref,icf -libpath:"C:\Perl586\lib\CORE" -machine:x86' Locally applied patches: ACTIVEPERL_LOCAL_PATCHES_ENTRY 21540 Fix backward-compatibility issues in if.pm 23565 Wrong MANIFEST.SKIP --- @INC for perl v5.8.6: c:/Perl586/lib c:/Perl586/site/lib . --- Environment for perl v5.8.6: HOME (unset) LANG (unset) LANGUAGE (unset) LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=c:\perl586\bin;C:\Perl582\bin\;C:\Perl\bin;C:\PROGRA~1\ESWM\CLIENT~1\BIN;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\UltraEdit;C:\Program Files\Microsoft SQL Server\80\Tools\BINN;R:\Resource\GPD\Scripts\Canada;R:\Resource\GPD\Scripts\ver1.40;R:\Resource\GPD\Scripts\Ver1.4;R:\Resource\GPD\Scripts\ver1.40;R:\Resource\bin;C:\Perl586\bin\;C:\Program Files\ATI Technologies\ATI Control Panel PERL_BADLANG (unset) SHELL (unset) ```

[p5pRT]

From p5p@perl.wizbit.be

Citeren Thushan Abeysekera \perlbug\-followup@​perl\.org​:

# New Ticket Created by "Thushan Abeysekera" # Please include the string​: [perl #57174] # in the subject line of all future correspondence about this issue. # \<URL​: http​://rt.perl.org/rt3/Ticket/Display.html?id=57174 >

This is a bug report for perl from thushan.abeysekera@​computershare.com\, generated with the help of perlbug 1.35 running under perl v5.8.6.

----------------------------------------------------------------- There seems to be a memory leak when doing recursion with goto
&sub_name syntax. Run following two endless loops and check memory usage. While script
1 runs out of memory\, script 2 runs without a problem.

[snip] Originally observed in​: perl\, v5.8.6 built for MSWin32-x86-multi-thread

This problem can be replicated in perl 5.10.0 i686-linux-thread-multi.

Please check http​://www.perlmonks.org/?node_id=698735 for a
discussion on this.

$ cat rt-57174.pl #!/usr/bin/perl -l

use strict; # use warnings;

my $mem1 = qx/ps u $$/; my ($vsz1) = $mem1 =~ m/^perl\s+\d+\s+[0-9.]+\s+[0-9.]+\s+(\d+)/m;

my $m = 0; test1();

my $mem2 = qx/ps u $$/; my ($vsz2) = $mem2 =~ m/^perl\s+\d+\s+[0-9.]+\s+[0-9.]+\s+(\d+)/m;

if ($vsz1 + 1000 \< $vsz2) {   print "not ok ($vsz1 & $vsz2)"; } else {   print "ok"; }

sub test1 {   my $v=0;   if ($v = get_true()) {   if ($m++ \< 300_000) {   goto &test1;   }   } }

sub get_true {   return 1; }

__END__

(running with user 'perl')

perl-5.00504 rt-57174.pl not ok (2708 & 14568)

perl-5.10.0 rt-57174.pl not ok (3172 & 9144)

perl-blead@​34156 rt-57174.pl not ok (3196 & 9172)

(No access to a system with a perl before 5.00504 atm)

Kind regards\,

Bram

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From @iabyn

Leak still present in bleed@​35059\, Dec 2008.