The API is exactly the same as Elixir stdlib Supervisor, except that the supervisor options now supports :delay_fun as an option.

The signature of :delay_fun is: (child_id :: term, ms_lifetime :: integer, acc :: term) -> {ms_delay_death :: integer, newacc:: term} The second argument ms_lifetime is the lifetime of the previously dead process. First start accumulator is nil.

This delay will be the minimum lifetime of the child in millisecond : child death will be delayed if it occurs too soon.

Below an example usage with an exponential backoff strategy: (200*2^count) ms delay where the backoff count is reset when previous run lifetime was > 5 secondes.

iex> import DelayedSup.Spec
  ...> import Bitwise
  ...> DelayedSup.start_link([
  ...>   worker(MyServer1,[]),
  ...>   worker(MyServer2,[])
  ...> ], restart_strategy: :one_for_one, delay_fun: fn count,_id-> 200*(1 <<< count) end)