defmodule PhiAccrualUdp do
  @moduledoc """
  Dedicated UDP socket source for [`phi_accrual`](https://hex.pm/packages/phi_accrual).

  Escapes BEAM distribution head-of-line blocking that affects the
  bundled `PhiAccrual.Source.DistributionPing` reference source. UDP
  heartbeats travel on their own socket, so a backed-up distribution
  port cannot delay them.

  ## Components

    * `PhiAccrualUdp.Packet` — wire format codec (12 bytes, magic +
      version + flags + timestamp).
    * `PhiAccrualUdp.Listener` — UDP receiver; calls
      `PhiAccrual.observe/2` with local receipt time.
    * `PhiAccrualUdp.Sender` — periodic UDP transmitter to a list of
      targets.

  ## Quick start

      # In your supervision tree
      children = [
        {PhiAccrualUdp.Listener, port: 4370},
        {PhiAccrualUdp.Sender,
          targets: [{{10, 0, 0, 2}, 4370}, {{10, 0, 0, 3}, 4370}],
          interval_ms: 1_000}
      ]

  ## Clock discipline

  This package preserves `phi_accrual`'s clock discipline: the
  detector reasons only about local monotonic receipt times. The
  packet timestamp field is diagnostic-only — it is NOT used for the
  EWMA. See `PhiAccrualUdp.Packet` moduledoc.
  """
end