Elixir simple_one_for_one 主管的 start_child 以未定义的 handle_call/3 终止

Question

我正在尝试使用 gproc 创建一个主管来进行进程注册。以下代码定义主管：

defmodule QueueSupervisor do
    use Supervisor

    def start_link do
        GenServer.start_link(__MODULE__, [], name: :model_queue)
    end

    def create_queue(name) do
        Supervisor.start_child(:model_queue, [name])
    end

    def init([]) do
        children = [
            worker(ModelQueueWriter, [])
        ]

        supervise(children, strategy: :simple_one_for_one)
    end

    def terminate(reason,_state) do
        Logger.info "terminating: #{inspect self}: #{inspect reason}"
        :ok
    end
end

主管开始很有魅力。但是，当调用 create_queue(:some_name) 时，出现未定义函数错误：

function QueueSupervisor.handle_call({:start_child, [:some_name]}, {#PID<0.2278.0>, #Reference<0.0.3.3361>}, {{:simple_one_for_one, 3, 5}, [{ModelQueueWriter, {ModelQueueWriter, :start_link, []}, :permanent, 5000, :worker, [ModelQueueWriter]}]}

ModelQueueWriter是一个简单的genserver，使用gproc进行命名：

defmodule ModelQueueWriter do
    use GenServer

    def start_link(queue_name) do
        GenServer.start_link(__MODULE__, [], name: via_tuple(queue_name))
    end

    defp via_tuple(queue_name) do
        {:via, :gproc, {:n, :l, {:model_queue, queue_name}}}
    end

    def init(_), do: %{:ok, []}
end

我正在使用 elixir 1.4 并遵循 Supervisor 的文档，加上这个 example。

我错过了什么？

根据请求提供完整的错误消息：

** (exit) exited in: GenServer.call(:model_queue, {:start_child, [:some_name]}, :infinity)
    ** (EXIT) an exception was raised:
        ** (UndefinedFunctionError) function QueueSupervisor.handle_call/3 is undefined or private
        (ecohesion_web) QueueSupervisor.handle_call({:start_child, [:model_queue]}, {#PID<0.2278.0>, #Reference<0.0.1.8826>}, {{:simple_one_for_one, 3, 5}, [{ModelQueueWriter, {ModelQueueWriter, :start_link, []}, :permanent, 5000, :worker, [ModelQueueWriter]}]})
        (stdlib) gen_server.erl:629: :gen_server.try_handle_call/4
        (stdlib) gen_server.erl:661: :gen_server.handle_msg/5
        (stdlib) proc_lib.erl:240: :proc_lib.init_p_do_apply/3
11:01:17.094 [error] GenServer :model_queue terminating
** (UndefinedFunctionError) function QueueSupervisor.handle_call/3 is undefined or private
(ecohesion_web) QueueSupervisor.handle_call({:start_child, [:model_queue]}, {#PID<0.2278.0>, #Reference<0.0.1.8826>}, {{:simple_one_for_one, 3, 5}, [{ModelQueueWriter, {ModelQueueWriter, :start_link, []}, :permanent, 5000, :worker, [ModelQueueWriter]}]})
(stdlib) gen_server.erl:629: :gen_server.try_handle_call/4
(stdlib) gen_server.erl:661: :gen_server.handle_msg/5
(stdlib) proc_lib.erl:240: :proc_lib.init_p_do_apply/3
Last message: {:start_child, [mode_queue]}
State: {{:simple_one_for_one, 3, 5}, [{ModelQueueWriter, {ModelQueueWriter, :start_link, []}, :permanent, 5000, :worker, [ModelQueueWriter]}]}
       (elixir) lib/gen_server.ex:737: GenServer.call/3
(ecohesion_web) lib/ecohesion_web/archive_writer/queue_supervisor.ex:28: QueueSupervisor.create_queue/1

Answer 1

您将在 QueueSupervisor.start_link/0 中开始 GenServer 而不是 Supervisor。这应该有效：

defmodule QueueSupervisor do
  def start_link do
    Supervisor.start_link(__MODULE__, [], name: :model_queue)
  end
end

Why does that even start the supervisor properly?

它启动了一个GenServer；只是您使用的参数与 Supervisor.start_link/3 和 GenServer.start_link/3.

兼容

Elixir simple_one_for_one 主管的 start_child 以未定义的 handle_call/3 终止

Elixir simple_one_for_one supervisor's start_child terminates with undefined handle_call/3

elixir

erlang-supervisor