关于 Task.Supervisor.async_stream_nolink 的示例？

Question

尝试应用Task.Supervisor.async_stream_nolink进行少量测试，但不起作用。

这是我的实现：

defmodule MySupervisor do
    use Supervisor

    def start_link do
        Supervisor.start_link(__MODULE__, [])
    end

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

        supervise(children, strategy: :one_for_one)
    end
end

defmodule Basic do
    use GenServer

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


strings = ["long string", "longer string", "there are many of these"]


stream = Task.Supervisor.async_stream_nolink(MySupervisor, strings, fn text -> text |> String.codepoints |> Enum.count end)


Enum.reduce(stream, 0, fn {:ok, num}, acc -> num + acc end) |> IO.puts

但是，我得到了错误：

**（从 #PID<0.70.0> 退出）退出于：GenServer.call(MySupervisor, {:start_child, [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0 >}, {:erlang, :apply, [#Function<0.118488666 in file:test.exs>, ["long string"]]}]}, :infinity) ** (EXIT) 没有进程：进程不是活动或当前没有与给定名称关联的进程，可能是因为其应用程序未启动

16:24:34.317 [错误] GenServer #PID<0.79​​.0> 终止 **（停止）退出于：GenServer.call(MySupervisor, {:start_child, [#PID<0.70.0>, :monitor, {:nonode @nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.118488666 in file:test.exs>, ["长字符串"]]}]}, :infin ity) ** ( EXIT) 无进程：进程不存在或当前没有与给定名称关联的进程，可能是因为其应用程序未启动 最后一条消息：{:EXIT, #PID<0.70.0>, {:noproc, {GenServer , :call, [MySupervisor, {:start_child, [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.118488666在文件：test.exs

, ["长字符串"]]}]}, :infinity]}}} 状态: {:state, {#PID<0.79​​.0>, MySupervisor}, :one_for_one, [{:child, #PID<0.80.0 >, 基本, {基本, :start_link, []}, :永久, 5000, :worker, [基本]}], :未定义, 3, 5, [], 0, MySupervisor, []}

有人可以帮忙吗？我找不到有关使用Task.Supervisor.async_stream_nolink 的示例

编辑

尝试直接使用我自己的主管而不在应用程序中使用它，我尝试了以下方法：

{:ok, supervisor} = MySupervisor.start_link
stream = Task.Supervisor.async_stream_nolink(supervisor, strings, fn text -> text |> String.codepoints |> Enum.count end)
Enum.reduce(stream, 0, fn {:ok, num}, acc -> num + acc end) |> IO.puts

但我得到了错误：

**（从 #PID<0.70.0> 退出）引发异常：**（MatchError）右侧值不匹配：{:error, {:EXIT, {:undef, [{Basic, :start_link, [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.20003547 in file:test.exs>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor.erl', 行: 381]}, {:supervisor, :handle_call, 3, [文件: 'supervisor .erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server.erl'，行：615]}，{：gen_server，：handle_msg，5，[文件：'gen_server.erl' '，行：647]}，{：proc_lib，：init_p_do_apply，3，[文件：'proc_lib.erl'，行：247]}]}}}（elixir）lib/task/supervisor.ex：265：匿名fn /4 在 Task.Supervisor.build_stream/5 (elixir) lib/task/supervised.ex:332: Task.Supervised.stream_monitor/6

17:07:53.497 [错误] 进程 #PID<0.81.0> 引发异常 ** (MatchError) 右侧值不匹配：{:error, {:EXIT, {:undef, [{Basic, :start_link , [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.20003547 in file:test. exs>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor.erl', 行: 381]}, {:supervisor, :handle_call, 3, [文件：'supervisor.erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server.erl'，行：615]}，{：gen_server，：handle_msg，5，[文件: 'gen_server.erl', 行: 647]}, {:proc_lib, :init_p_do_apply, 3, [文件: 'proc_lib.erl', 行: 247]}]}}} (elixir) lib/task/supervisor.ex :265: Task.Supervisor.build_stream/5 中的匿名 fn/4 (elixir) lib/task/supervised.ex:332: Task.Supervised.stream_monitor/6

17:07:53.503 [错误] GenServer MySupervisor 终止 ** (MatchError) 右侧值不匹配：{:error, {:EXIT, {:undef, [{Basic, :start_link, [#PID<0.70.0 >, :monitor, {:nonode@nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.20003547 in file:test. exs>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor.erl', 行: 381]}, {:supervisor, :handle_call, 3, [文件：'supervisor.erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server.erl'，行：615]}，{：gen_server，：handle_msg，5，[文件: 'gen_server.erl', 行: 647]}, {:proc_lib, :init_p_do_apply, 3, [文件: 'proc_lib.erl', 行: 247]}]}}} (elixir) lib/task/supervisor.ex :265: Task.Supervisor.build_stream/5 中的匿名 fn/4 (elixir) lib/task/supervised.ex:332: Task.Supervised.stream_monitor/6 最后一条消息: {:EXIT, #PID<0.70.0>, {{:badmatch, {:error, {:EXIT, {:undef, [{Basic, :start_link, [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>} , {:erlang, :apply, [#Function<0.20003547 in file:test.ex s>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor .erl'，行：381]}，{：supervisor，：handle_call，3，[文件：'supervisor.erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server。 erl'，行：615]}，{：gen_server，：handle_msg，5，[文件：'gen_server.erl'，行：647]}，{：proc_lib，：init_p_do_apply，3，[文件：'proc_lib.erl' ，行：247]}]}}}}，[{Task.Supervisor，："-build_str eam/5-fun-0-"，4，[文件：'lib/task/supervisor.ex'，行：265 ]}, {Task.Supervised, :stream_monitor, 6, [文件: 'lib/task/supervised.ex', 行: 332]}]}} 状态: {:state, {:local, MySupervisor}, :simple_one_for_one, [{:child, :undefined, Basic, {Basic, :start_link, []}, :permanent, 5000, :worker, [Basic]}], :undefined, 3, 5, [], 0, MySupervisor, [] }

17:07:53.505 [错误] GenServer #PID<0.79​​.0> 终止 ** (MatchError) 右侧值不匹配：{:error, {:EXIT, {:undef, [{Basic, :start_link, [ #PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>}, {:erlang, :apply, [#Function<0.20003547 in file:test. exs>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor.erl', 行: 381]}, {:supervisor, :handle_call, 3, [文件：'supervisor.erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server.erl'，行：615]}，{：gen_server，：handle_msg，5，[文件: 'gen_server.erl', 行: 647]}, {:proc_lib, :init_p_do_apply, 3, [文件: 'proc_lib.erl', 行: 247]}]}}} (elixir) lib/task/supervisor.ex :265: Task.Supervisor.build_stream/5 中的匿名 fn/4 (elixir) lib/task/supervised.ex:332: Task.Supervised.stream_monitor/6 最后一条消息: {:EXIT, #PID<0.70.0>, {{:badmatch, {:error, {:EXIT, {:undef, [{Basic, :start_link, [#PID<0.70.0>, :monitor, {:nonode@nohost, #PID<0.81.0>} , {:erlang, :apply, [#Function<0.20003547 in file:test.ex s>, ["长字符串"]]}], []}, {:supervisor, :do_start_child_i, 3, [文件: 'supervisor .erl'，行：381]}，{：supervisor，：handle_call，3，[文件：'supervisor.erl'，行：406]}，{：gen_server，：try_handle_call，4，[文件：'gen_server。 erl'，行：615]}，{：gen_server，：handle_msg，5，[文件：'gen_server.erl'，行：647]}，{：proc_lib，：init_p_do_apply，3，[文件：'proc_lib.erl' ，行：247]}]}}}}，[{Task.Supervisor，："-build_str eam/5-fun-0-"，4，[文件：'lib/task/supervisor.ex'，行：265 ]}, {Task.Supervised, :stream_monitor, 6, [文件: 'lib/task/supervised.ex', 行: 332]}]}} 状态: {:state, {#PID<0.79​​.0>, Supervisor .Default}, :simple_one_for_one, [{:child, :undefined, Task.Supervised, {Task.Supervised, :start_link, []}, :temporary, 5000, :worker, [Task.Supervised]}], :undefined, 3 , 5, [], 0, Supervisor.Default, {:ok, {{:simple_one_for_one, 3, 5}, [{Task.Supervised, {Task.Supervised, :start_link, []}, :temporary, 5000, :worker, [任务.监督]}]}}}

Answer 1

中的函数Task.Supervisor只能在以 启动的 Supervisor 上运行Task.Supervisor.start_link/1。

您可以启动一个未命名的实例并将 pid 传递给async_stream_nolink/4：

{:ok, supervisor} = Task.Supervisor.start_link
stream = Task.Supervisor.async_stream_nolink(supervisor, strings, fn text -> text |> String.codepoints |> Enum.count end)

或启动一个命名实例并传递其名称：

Task.Supervisor.start_link name: MySupervisor
stream = Task.Supervisor.async_stream_nolink(MySupervisor, strings, fn text -> text |> String.codepoints |> Enum.count end)

两种情况的输出都是47。

如果您希望此主管与您的应用程序一起运行，您可以将其添加到应用程序现有的顶级主管下，如下所示：

children = [
  supervisor(Task.Supervisor, [name: MySupervisor]),
  ...
]

然后做

Task.Supervisor.async_stream_nolink(MySupervisor, ...)