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理解药剂BADARG错误信息

elixir erlang

user3139545 · 技术社区 · 6 年前

当我试图从一个 DynamicSupervisor 我得到以下错误:

{:error,
 {:EXIT,
  {:badarg,
   [
     {:erlang, :apply,
      [
        BfgEngine.MarketService,
        :start_link,
        {{BfgEngine.MarketService, :start_link, ["1111"]}, :permanent, 5000,
         :worker, [BfgEngine.MarketService]}
      ], []},
     {:supervisor, :do_start_child_i, 3, [file: 'supervisor.erl', line: 379]},
     {:supervisor, :handle_call, 3, [file: 'supervisor.erl', line: 404]},
     {:gen_server, :try_handle_call, 4, [file: 'gen_server.erl', line: 661]},
     {:gen_server, :handle_msg, 6, [file: 'gen_server.erl', line: 690]},
     {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}
   ]}}}

IM使用的代码是:

  def start_market(market_id) do
    spec = {MarketService, market_id}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

但是我不清楚出了什么问题。哪个函数的参数不正确?如何分解并读取给定的错误消息?

更新:

这是我主管的初始化方法:

  @impl true
  def init(initial_arg) do
    DynamicSupervisor.init(
      strategy: :one_for_one,
      extra_arguments: [initial_arg]
    )
  end

更新2: 这是市场服务的起始链接:

  def start_link(market_id) when is_bitstring(market_id) do
    GenServer.start_link(__MODULE__, market_id, name: via_tuple(market_id))
  end

IM使用默认值 child_spec 我来自 GenServer

更新3: 更改为:

  def start_market(market_id) do
    spec = {MarketService, market_id: market_id}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

给予:

{:error,
 {:undef,
  [
    {BfgEngine.MarketService, :start_link, [[], [market_id: "222"]], []},
    {DynamicSupervisor, :start_child, 3,
     [file: 'lib/dynamic_supervisor.ex', line: 654]},
    {DynamicSupervisor, :handle_start_child, 2,
     [file: 'lib/dynamic_supervisor.ex', line: 640]},
    {:gen_server, :try_handle_call, 4, [file: 'gen_server.erl', line: 661]},
    {:gen_server, :handle_msg, 6, [file: 'gen_server.erl', line: 690]},
    {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}
  ]}}

更改为:

  def start_market(market_id) do
    spec = {MarketService, :market_id, market_id}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

给予:

** (ArgumentError) supervisors expect each child to be one of:

  * a module
  * a {module, arg} tuple
  * a child specification as a map with at least the :id and :start fields
  * or a tuple with 6 elements generated by Supervisor.Spec (deprecated)

Got: {BfgEngine.MarketService, :market_id, "222"}

    (elixir) lib/supervisor.ex:657: Supervisor.init_child/1
    (elixir) lib/supervisor.ex:744: Supervisor.child_spec/2
    (elixir) lib/dynamic_supervisor.ex:304: DynamicSupervisor.start_child/2

2 回复 | 直到 6 年前

Milan Jaric 6 年前

从发布的代码很难分辨,但你能试着改变吗 start_market 到:

  def start_market(market_id) do
    spec = {MarketService, :market_id, market_id}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

更新(以下是两个选项):

  def start_market(market_id) do
    spec = &{
      id: MarketService,
      start: {MarketService, start_link, [market_id]},
      type: :worker
    }
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

或者

  def start_market(market_id) do
    spec = {MarketService, [market_id]}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

Hynek -Pichi- Vychodil Paulo Suassuna 6 年前

你有 badarg 功能异常 erlang:apply/3 当有三个论点时 BfgEngine.MarketService 我是说, :start_link 和 {{BfgEngine.MarketService, :start_link, ["1111"]}, :permanent, 5000, :worker, [BfgEngine.MarketService]} 它发生在功能上 supervisor:do_start_child_i/3 是的。

函数的参数 erlang:应用/3 应该是mfa a.k.a模块、函数、参数。 {{bfgengine.marketservice,:开始链接,[“1111”]},:永久的,5000,:工作者,[bfgengine.marketservice]} 不是争论,因为它显然不是 参数列表 是的。从你的代码中,我可以猜出错误是变量的内容 spec 是的。你应该提供一些道具或地图。我不知道,你应该看看 DynamicSupervisor 小心点。