P:\test>perl -Mthreads -l
$|=1;
sub f{ print $_[0]; sleep 5; print $_[0]; }
threads->create( \&f, \&f ) for 1..2;
$_->join for threads->list;
print 'done';
^Z
CODE(0x1bf9b7c)
CODE(0x1c23c24)
CODE(0x1bf9b7c)
CODE(0x1c23c24)
done