Actually run a function a certain percentage of the time in PHP

Question

How can I write a function in PHP to call a given function (anonymous) X% of the time?

For example:

function call_weighted(0.1, function() {
      echo 'this is actually run approximately 10% of the times it is called';
});

Answer 1

function call_weighted($weight, $function) {
    if (mt_rand() < $weight * mt_getrandmax()) {
        $function();
    }
}