Hello all,

in the perl documentation I've read about some statements that could result in memory leaks, but I don't understand what the real problem is and if some code I use should be avoided because it has the same problem. I would be happy if someone could give me some advise and lighten my darkness.

Let me quote:

A more serious concern is that unreachable memory with a non-zero reference count will not normally get freed. Therefore, this is a bad idea: 
{
  my $a;
  $a = \$a;
}

[download]

http://perldoc.perl.org/perlobj.html#Two-Phased-Garbage-Collection

Is the problem that $a is declared in the block, but never assigned with something and never used elsewhere? If I would assign $a a value from somewhere and do use it somewhere else, do I have the same problem?

I have code like the following: 

sub foo
{
  my $retVal = undef;
  $retVal = $someObject->bar()->doSomething();
  $retVal = \$retVal;

  Log4perl->debug('retval: ', sub {$retVal});

  return $retVal;
}

[download]

The goal of the above is to let foo return a reference to a string, but just have to create that reference once and to use it as a return value and for logging purposes. Does this produces memory leaks like stated in the perl documentation?

Thanks for your hints.

In reply to unreachable memory with a non-zero reference count by Pickwick

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