use Proc::Queue size=>2, qw(run_back);
Proc::Queue::trace(1);

my @ARGV = ("file1.fasta","file2.fasta");

for ( @ARGV  )
{  run_back
   {
      eval{  run_code($_) };
      print STDERR $0."[$$]: $@\n" if $@;
   }

}
1 while wait != -1;

run_code {
  my $file = shift;
  #do the rest
}