what best slight removing database connection/object duty php?

a integrate options are:

$connection = {my db connection/object};

function passedin($connection) { ... }

function passedbyreference(&$connection) { ... }

function usingglobal() {
    tellurian $connection;
    ...
}

so, upheld in, upheld reference, controlling global. i'm pondering functions wholly used within 1 digest wholly have 1 database connection. there churned connections, unequivocally upheld passed reference.

i'm thining upheld anxiety indispensable php5 controlling an object, following upheld controlling tellurian 2 possibilities.

the reason i'm seeking since i'm removing sleepy always putting $connection duty parameters.