debugger space leak using conditional breakpoints

[p5pRT]

Migrated from rt.perl.org#1542 (status was 'resolved')

Searchable as RT1542$

[p5pRT]

From mjtg@cus.cam.ac.uk

Try

perl -wde 'my $a = 0 for 1..10000000'

Loading DB routines from perl5db.pl version 1.0402
Emacs support available.

Enter h or `h h' for help.

main​::(-e​:1)​: my $a = 0 for 1..10000000
  DB<1> b 1 $a
  DB<2> c

and watch the swap space evaporate (fairly slowly).

Curiously, it doesn't leak if the command line is

  perl -wde 'my $a = 0 while 1'

The effect occurs in both maintenance and development versions, on
several platforms.

BTW the slightly odd 'b 1 $a' is used because the more obvious 'b 1 0'
doesn't work - it gives "always true" instead of "always false".
Dunno if that's a bug or a feature.

Mike Guy

% perl5.005_57 -V
Summary of my perl5 (revision 5.0 version 5 subversion 57) configuration​:
  Platform​:
  osname=sunos, osvers=4.1.3, archname=sun4-sunos
  uname=''
  config_args='-Doptimise='-O' -Uusethreads -dOes -f confug.sh'
  hint=previous, useposix=true, d_sigaction=define
  usethreads=undef useperlio=undef d_sfio=undef
  use64bits=undef usemultiplicity=undef
  Compiler​:
  cc='gcc', optimize='-O', gccversion=2.7.2.3
  cppflags='-I/usr/local/include -DREG_INFTY=22790'
  ccflags ='-I/usr/local/include -DREG_INFTY=22790'
  stdchar='unsigned char', d_stdstdio=define, usevfork=true
  intsize=4, longsize=4, ptrsize=4, doublesize=8
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=8
  alignbytes=8, usemymalloc=y, prototype=define
  Linker and Libraries​:
  ld='ld', ldflags =' -L/usr/local/lib'
  libpth=/usr/local/lib /lib /usr/lib /usr/ucblib
  libs=-ldbm -ldl -lm -lc -lposix
  libc=/lib/libc.so.1.8, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
  cccdlflags='-fpic', lddlflags='-assert nodefinitions -L/usr/local/lib'

Characteristics of this binary (from libperl)​:
  Built under sunos
  Compiled at May 27 1999 10​:39​:53
  @​INC​:
  /home/mjtg/perl5.005_57/lib
  /home/mjtg/perl5.005_57/lib
  /home/mjtg/perl5.005_57/lib
  .

[p5pRT]

From [Unknown Contact. See original ticket]

This bug appears to still be valid as of @​8229.

[spp@​belgarion bleadperl]$ ./perl -wde 'my $a = 0 for 1..10000000'
Default die handler restored.

Loading DB routines from perl5db.pl version 1.07
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main​::(-e​:1)​: my $a = 0 for 1..10000000
  DB<1> b 1 $a
  DB<2> c
main​::(-e​:1)​: my $a = 0 for 1..10000000
  DB<2> q

watch swap space evaporate (fairly slowly).

[p5pRT]

From @schwern

This bug appears to have been resolved somewhere before 5.8.6. The
construct no longer consumes additional memory.

[p5pRT]

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