An embodiment method for retiring a dynamically updatable function includes receiving, by a collector-thread, a registration of the function, wherein the registration indicates to the collector-thread addresses of memory locations for counters that count a number of calls currently being made to a previous version of the function by a plurality of execution threads; reading, by the collector-thread, values of the counters; and when the values of all the counters are zero, deleting, by the collector-thread, the function from a storage medium on a device previously executing the previous version of the function.