A method that performs exponential backoff on a callback method

executeWithExponentialBackOff.php

<?php
// $this->executeWithExponentialBackOff("self::myMethodName", array("id" => 1), 64);

// in this exmaple myFunctionName() is private and resides in the same class as executeWithExponentialBackOff().
// myFunctionName() has to throw an exception when it fails for the backoff to be performed.

class Foo
{
    private function executeWithExponentialBackOff($callback, $parameters, $timeout)
    {
        $results = null;

        $success = true;
        $backoffSeconds = 1;
        do {
            if (!$success) {
                \printf("Backing-off for %s and retrying...%s", $backoffSeconds, PHP_EOL);
                \sleep($backoffSeconds);
            }

            try {
                $results = \call_user_func_array($callback, $parameters);

                $success = true;
                $backoffSeconds = 1;
            } catch (\Exception $ex) {
                $success = false;

                $errorMessage = \sprintf("Function failed with error: \"%s\".", $ex->getMessage());

                $backoffSeconds = $backoffSeconds << 1;

                if ($backoffSeconds >= $timeout) {
                    \printf("Quitting, backoff timeout reached :-(%s", PHP_EOL);

                    break;
                }

                \printf("%s%s", $errorMessage, PHP_EOL);
            }
        } while (!$success);

        return $results;
    }
}