Object Log, when dumped, looks like this:

$VAR1 = bless({'options' => 
        {'filehandle' => 
         bless( \*Symbol::GEN2, 'FileHandle' ),
        'filename' => 'a.log'},}, 'Log' );
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Log object provides the methods filehandle() and filename() to set the above values (and ofcourse, a $log->print()). I have a large codebase, that I'm modifying to enable parallel processing of various parts, with minimum changes to the codebase. So the call:

$self->do_task()
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becomes:

Process::spawn(\&do_task, $self);
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The problem is, $self has references to the log object at various places. I want all the output of the spawned process to go to a new file. So I do something like this:

$new_log = new Log(filename => 'new.log');
$cur_log = $self->{log};
$self->{log} = $new_log;
Process::spawn(\&do_task, $self); # This runs in background.
$self->{log} = $cur_log; # Restore.
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But alas !, $self also has various other references to log, embedded deep inside, like:

$self->{system}->{log},
$self->{filecache}->{system}->{log}
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...etc. Since these log objects are created in the parent, at various points in the code, they all refer to the parent filehandle. I cannot change the parent code; So I need to do some gimmick to find out all these references to Log and replace them with $new_log.

@ref = Devel::ObjSearch($self, 
sub { return UNIVERSAL::isa($_[0], 'Log'); });
foreach (@ref) { $_->filename('new.log'); $_->filehandle($new_log); }
.. spawn() ..
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