my @threads = map{ 
    threads->new( \&process3, 0, $endline, $_ 
} qw[ 
    c001n05 c001n06 c001n07 c001n08 c001n09 c001n10
    c001n11 c001n12 c001n13 c001n14 c001n15 c001n16
];

$_->join for @threads;