Leak.pm

   1 package Devel::Leak;
   2 use 5.005;
   3 use vars qw($VERSION);
   4 require DynaLoader;
   5 use base qw(DynaLoader);
   6 $VERSION = '0.05';
   7
   8 bootstrap Devel::Leak;
   9
  10 1;
  11 __END__
  12
  13 =head1 NAME
  14
  15 Devel::Leak - Utility for looking for perl objects that are not reclaimed.
  16
  17 =head1 SYNOPSIS
  18
  19   use Devel::Leak;
  20   ... setup code
  21
  22   my $count = Devel::Leak::NoteSV($handle);
  23
  24   ... code that may leak
  25
  26   Devel::Leak::CheckSV($handle);
  27
  28 =head1 DESCRIPTION
  29
  30 Devel::Leak has two functions C<NoteSV> and C<CheckSV>.
  31
  32 C<NoteSV> walks the perl internal table of allocated SVs (scalar values) - (which
  33 actually  contains arrays and hashes too), and records their addresses in a
  34 table. It returns a count of these "things", and stores a pointer to the
  35 table (which is obtained from the heap using malloc()) in its argument.
  36
  37 C<CheckSV> is passed argument which holds a pointer to a table created by
  38 C<NoteSV>. It re-walks the perl-internals and calls sv_dump() for any "things"
  39 which did not exist when C<NoteSV> was called. It returns a count of the number
  40 of "things" now allocated.
  41
  42 =head1 CAVEATS
  43
  44 If new "things" I<have> been created, C<CheckSV> may (also) report additional
  45 "things" which are allocated by the sv_dump() code.
  46
  47 =head1 NOTES
  48
  49 Note that perls older than 5.6.0 need to be built with -DDEBUGGING
  50 for sv_dump() to print anything, but counts are valid in any perl.
  51
  52 =head1 HISTORY
  53
  54 This little utility module was part of Tk until the variable renaming
  55 in perl5.005 made it clear that Tk had no business knowing this much
  56 about the perl internals.
  57
  58 =head1 AUTHOR
  59
  60 Nick Ing-Simmons <nick@ni-s.u-net.com>
  61
  62 =cut
  63