http://www.perlmonks.org?node_id=865899

menth0l has asked for the wisdom of the Perl Monks concerning the following question:

Hi, Is there any way to prevent cloning an object/class of objects from being cloned while creating new thread? When i do something like:
package MyPackage; use threads; use threads::shared; { use Object::InsideOut qw(:NOT_SHARED); }; package main; use threads; my $o = new MyPackage; threads->create(\&th)->join(); sub th { my $o1 = new MyPackage; }
i get:
ERROR: Attempt to DESTROY object ID 1 of class MyPackage twice ERROR: Attempt to DESTROY object ID 1 of class MyPackage twice Scalars leaked: 1
I assume that new thread copies $o (id = 1) into its scope and then tries to destroy it at the and along with $o1 which have the same id (1) since it's just cloned version of $o. Now, how can i prevent this? One way would be to create o _after_ thread is created (but that limits ways of using 'MyPackage' and i don't want that). Second: ensuring that $o1 would get new id (but how?). Third: ensuring that new thread would get undef as a $o value so that destroy method would not be invoked (but once again: how?). Of course i could mark MyPackage as :SHARED but in my real app this class consist of fields which are classes that cannot be shared. So, is there any other way to get rid of those annoying memory leaks?