use threads('yield','stack_size' => 64*4096, 'exit' => 'threads_only', 'stringify');
use Thread::Queue;
use various others(File::..., DBI....

my @FoundFiles = subroutine to get all of the applicable files(and their directories).
my $Threads = 8;
my $workq = Thread::Queue->new();

$workq->enqueue(@FoundFiles);
$workq->enqueue(undef) for (1..$Threads);

threads->create('executeall') for (1..$Threads);

sub executeall
{
      while(my $i = $workq->dequeue())
      {
            last if $i eq undef;
            if($i =~ /filetypea/)
            {
                  parseitthisway($i);
            }
            if($i =~ /filetypeb/)
            {
                  parseitanotherway($i);
            }
            ....
            ....
      }
      threads->detach();
}