GenServer Timeout

gen_sasha.ex

defmodule Caller do
  use GenServer
  @spec start_link(list(any())) :: GenServer.on_start()
  def start_link(default) when is_list(default) do
    GenServer.start_link(__MODULE__, default)
  end

  def call do
    Server.call
  end

  @impl true
  def init(_arg) do
    Process.flag(:trap_exit, true)
    Process.register(self(), :caller)
    {:ok, %{}}
  end

  @impl true
  def handle_info(msg, state) do
    IO.puts("-------> #{msg}")

    {:noreply, state}
  end

  @impl true
  def terminate(reason, state) do
    IO.puts("-------> TERMINATE CALLER")
    :ok
  end
end

defmodule Server do
  use GenServer

  # Client
  @spec start_link(list(any())) :: GenServer.on_start()
  def start_link(default) when is_list(default) do
    GenServer.start_link(__MODULE__, default)
  end

  def call do
    response =
      Process.whereis(:worker)
      |> GenServer.call(:fetch)
  end

  # Server (callbacks)
  @impl true
  def init(_arg) do
    Process.flag(:trap_exit, true)
    Process.register(self(), :worker)
    {:ok, %{}}
  end

  @impl true
  def handle_info(msg, state) do
    IO.puts("-------> #{msg}")

    {:noreply, state}
  end

  def terminate(reason, state) do
    IO.puts("-------> TERMINATE SERVER")
    :ok
  end

  @impl true
  def handle_call(:fetch, _from, state) do
    IO.puts("------> SNAITAS")
    :timer.sleep(6000)

    {:reply, :ok, state}
  end
end