From perl-5.8.0@ton.iguana.be

Created by perl-5.8.0@ton.iguana.be

#! /usr/bin/perl -w
my @​F = 1..10;
{
  redo while @​F;
} continue {
}

leaks many megabytes per second

Flags:
    category=core
    severity=low

Site configuration information for perl v5.8.2:

Configured by ton at Sun Jan  4 19:19:06 CET 2004.

Summary of my perl5 (revision 5.0 version 8 subversion 2) configuration:
  Platform:
    osname=linux, osvers=2.6.0, archname=i686-linux-64int-ld
    uname='linux quasar 2.6.0 #3 thu dec 18 18:22:48 cet 2003 i686 gnulinux '
    config_args=''
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=define use64bitall=undef uselongdouble=define
    usemymalloc=y, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -fomit-frame-pointer',
    cppflags='-fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='3.4.0 20031231 (experimental)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long long', ivsize=8, nvtype='long double', nvsize=12, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -ldb -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.3.2.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.3.2'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl v5.8.2:
    /usr/lib/perl5/5.8.2/i686-linux-64int-ld
    /usr/lib/perl5/5.8.2
    /usr/lib/perl5/site_perl/5.8.2/i686-linux-64int-ld
    /usr/lib/perl5/site_perl/5.8.2
    /usr/lib/perl5/site_perl
    .


Environment for perl v5.8.2:
    HOME=/home/ton
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/ton/bin.Linux:/home/ton/bin:/home/ton/bin.SampleSetup:/usr/local/bin:/usr/local/sbin:/usr/local/jre/bin:/home/oracle/product/9.0.1/bin:/usr/local/ar/bin:/usr/games/bin:/usr/X11R6/bin:/usr/share/bin:/usr/bin:/usr/sbin:/bin:/sbin:.
    PERL_BADLANG (unset)
    SHELL=/bin/bash

From @rgs

Perl-5.8.0@​Ton.Iguana.Be wrote in perl.perl5.porters :

#! /usr/bin/perl -w
my @​F = 1..10;
{
redo while @​F;
} continue {
}

leaks many megabytes per second

according to valgrind, this leak is fixed in bleadperl. I don't
know whether it is in maint.

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

From @mhx

On 2004-03-03, at 10​:29​:25 -0000, Rafael Garcia-Suarez wrote​:

Perl-5.8.0@​Ton.Iguana.Be wrote in perl.perl5.porters :

#! /usr/bin/perl -w
my @​F = 1..10;
{
redo while @​F;
} continue {
}

leaks many megabytes per second

according to valgrind, this leak is fixed in bleadperl. I don't
know whether it is in maint.

It may not be a memory "leak", but the above program is eating
up the whole memory within seconds, for whatever reason. Even
with blead and maint.

--
Thus spake the master programmer​:
  "When a program is being tested, it is too late to make design changes."
  -- Geoffrey James, "The Tao of Programming"

From @iabyn

On Wed, Mar 03, 2004 at 10​:29​:25AM -0000, Rafael Garcia-Suarez wrote​:

Perl-5.8.0@​Ton.Iguana.Be wrote in perl.perl5.porters :

#! /usr/bin/perl -w
my @​F = 1..10;
{
redo while @​F;
} continue {
}

leaks many megabytes per second

according to valgrind, this leak is fixed in bleadperl. I don't
know whether it is in maint.

Nope, it still leaks in bleed. The problem (I think) is that pp_enter is
called too often, so the save stack grows without bounds

$ ./perl -Dt /tmp/p
...
(/tmp/p​:3) enter
(/tmp/p​:3) nextstate
(/tmp/p​:3) enter
(/tmp/p​:3) padav(@​F)
(/tmp/p​:3) and
(/tmp/p​:3) redo
(rinse and repeat)

9 <;> nextstate(main 4 p​:4) v ->a
l <2> leaveloop vK/2 ->m
a <{> enterloop(next->k last->l redo->b) v ->b
- <@​> lineseq vK ->l
j <@​> leave vKP ->k
b <0> enter v ->c
c <;> nextstate(main 2 p​:3) v ->d
i <@​> leave vK* ->j
d <0> enter v ->e
- <1> null vKP/1 ->i
f <|> and(other->g) vK/1 ->i
e <0> padav[@​F​:1,4] s ->f
- <@​> lineseq vK ->-
g <0> redo v* ->h
h <0> unstack v ->e
- <@​> scope vK ->-
k <0> stub v ->l

compared with when the continue block is omitted​:

(/tmp/p​:3) nextstate
(/tmp/p​:3) enter
(/tmp/p​:3) padav(@​F)
(/tmp/p​:3) and
(/tmp/p​:3) redo
(rinse and repeat)

9 <;> nextstate(main 3 p​:3) v ->a
i <2> leaveloop vK/2 ->j
a <{> enterloop(next->i last->i redo->b) v ->b
- <@​> lineseq vKP ->i
b <;> nextstate(main 2 p​:3) v ->c
h <@​> leave vK* ->i
c <0> enter v ->d
- <1> null vKP/1 ->h
e <|> and(other->f) vK/1 ->h
d <0> padav[@​F​:1,3] s ->e
- <@​> lineseq vK ->-
f <0> redo v* ->g
g <0> unstack v ->d

--
This email is confidential, and now that you have read it you are legally
obliged to shoot yourself. Or shoot a lawyer, if you prefer. If you have
received this email in error, place it in its original wrapping and return
for a full refund. By opening this email, you accept that Elvis lives.

From @rgs

Quoting Marcus Holland-Moritz <mhx@​gmx.de>​:

according to valgrind, this leak is fixed in bleadperl. I don't
know whether it is in maint.

It may not be a memory "leak", but the above program is eating
up the whole memory within seconds, for whatever reason. Even
with blead and maint.

Fair enough. Feeling confused.

From @iabyn

On Wed, Mar 03, 2004 at 10​:48​:19AM +0000, Dave Mitchell wrote​:

On Wed, Mar 03, 2004 at 10​:29​:25AM -0000, Rafael Garcia-Suarez wrote​:

Perl-5.8.0@​Ton.Iguana.Be wrote in perl.perl5.porters :

#! /usr/bin/perl -w
my @​F = 1..10;
{
redo while @​F;
} continue {
}

leaks many megabytes per second

according to valgrind, this leak is fixed in bleadperl. I don't
know whether it is in maint.

Nope, it still leaks in bleed. The problem (I think) is that pp_enter is
called too often, so the save stack grows without bounds

Correction​: its the the tmps stack that grows without bounds.

It can be demonstrated with the even simpler code​:

  my @​F = (1);
  {
  @​F && redo;
  }
  continue {
  }

The @​f in scalar context pushes a mortal IV(1) onto the tmps stack;
without the continue block the instruction following the redo is a
nextstate which promptly pops the tmp off again; in the presence of the
continue block, there is an an enter before the nextstate, so tmps_floor
gets bumped up, and the nextstate doesn't release the IV(1).

The following patch fixes it by doing a FREETMPS at the end of pp_redo();
however I haven't applied it yet because I'm not sure its the best fix.
(Or even that a correct one!)

Dave.

--
To collect all the latest movies, simply place an unprotected ftp server
on the Internet, and wait for the disk to fill....

--- pp_ctl.c-	Wed Mar  3 20:45:13 2004
+++ pp_ctl.c	Wed Mar  3 20:45:32 2004
@@ -2115,6 +2115,7 @@ PP(pp_redo)
     TOPBLOCK(cx);
     oldsave = PL_scopestack[PL_scopestack_ix - 1];
     LEAVE_SCOPE(oldsave);
+    FREETMPS;
     return cx->blk_loop.redo_op;
 }

From @iabyn

On Wed, Mar 03, 2004 at 09​:07​:35PM +0000, Dave Mitchell wrote​:

The following patch fixes it by doing a FREETMPS at the end of pp_redo();
however I haven't applied it yet because I'm not sure its the best fix.
(Or even that a correct one!)

In the absence of any negative feedback or better ideas, I've now applied
it (along with a test) as change #22438.

--
"Emacs isn't a bad OS once you get used to it.
It just lacks a decent editor."

@iabyn - Status changed from 'open' to 'resolved'