$latency = .050; // latency skew (err towards keeping lock present)
$age = ( microtime( true ) - $lSince + $latency );
if ( ( $age + $latency ) >= $expiry ) {
$latency = .050; // latency skew (err towards keeping lock present)
$age = ( microtime( true ) - $lSince + $latency );
if ( ( $age + $latency ) >= $expiry ) {