Current File : //usr/share/perl5/vendor_perl/B/Hooks/EndOfScope/PP/FieldHash.pm
# Implementtion of a pure-perl on_scope_end for perls > 5.10
# (relies on Hash::Util:FieldHash)
package # hide from pause
B::Hooks::EndOfScope::PP::FieldHash;
use strict;
use warnings;
use warnings;
use strict;
use Tie::Hash ();
use Hash::Util::FieldHash 'fieldhash';
# Here we rely on a combination of several behaviors:
#
# * %^H is deallocated on scope exit, so any references to it disappear
# * A lost weakref in a fieldhash causes the corresponding key to be deleted
# * Deletion of a key on a tied hash triggers DELETE
#
# Therefore the DELETE of a tied fieldhash containing a %^H reference will
# be the hook to fire all our callbacks.
fieldhash my %hh;
{
package # hide from pause too
B::Hooks::EndOfScope::PP::_TieHintHashFieldHash;
use base 'Tie::StdHash';
sub DELETE {
my $ret = shift->SUPER::DELETE(@_);
B::Hooks::EndOfScope::PP::__invoke_callback($_) for @$ret;
$ret;
}
}
sub on_scope_end (&) {
$^H |= 0x020000;
tie(%hh, 'B::Hooks::EndOfScope::PP::_TieHintHashFieldHash')
unless tied %hh;
push @{ $hh{\%^H} ||= [] }, shift;
}
1;
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