From 5dd3b82e1ff280e894f96bf57c40116c3c1364eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonatan=20K=C5=82osko?= <jonatanklosko@gmail.com>
Date: Tue, 20 Apr 2021 20:03:13 +0200
Subject: [PATCH] Don't register named supervisors on remote node (#230)

---
 .../runtime/erl_dist/evaluator_supervisor.ex  | 19 ++++++++++---------
 lib/livebook/runtime/erl_dist/manager.ex      | 12 +++++++-----
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/lib/livebook/runtime/erl_dist/evaluator_supervisor.ex b/lib/livebook/runtime/erl_dist/evaluator_supervisor.ex
index 6b239c926..38017e6db 100644
--- a/lib/livebook/runtime/erl_dist/evaluator_supervisor.ex
+++ b/lib/livebook/runtime/erl_dist/evaluator_supervisor.ex
@@ -8,10 +8,8 @@ defmodule Livebook.Runtime.ErlDist.EvaluatorSupervisor do
 
   alias Livebook.Evaluator
 
-  @name __MODULE__
-
   def start_link(opts \\ []) do
-    DynamicSupervisor.start_link(__MODULE__, opts, name: @name)
+    DynamicSupervisor.start_link(__MODULE__, opts)
   end
 
   @impl true
@@ -22,9 +20,12 @@ defmodule Livebook.Runtime.ErlDist.EvaluatorSupervisor do
   @doc """
   Spawns a new evaluator.
   """
-  @spec start_evaluator() :: {:ok, Evaluator.t()} | {:error, any()}
-  def start_evaluator() do
-    case DynamicSupervisor.start_child(@name, {Evaluator, [formatter: Evaluator.StringFormatter]}) do
+  @spec start_evaluator(pid()) :: {:ok, Evaluator.t()} | {:error, any()}
+  def start_evaluator(supervisor) do
+    case DynamicSupervisor.start_child(
+           supervisor,
+           {Evaluator, [formatter: Evaluator.StringFormatter]}
+         ) do
       {:ok, pid} -> {:ok, pid}
       {:ok, pid, _} -> {:ok, pid}
       :ignore -> {:error, :ignore}
@@ -35,9 +36,9 @@ defmodule Livebook.Runtime.ErlDist.EvaluatorSupervisor do
   @doc """
   Terminates the given evaluator.
   """
-  @spec terminate_evaluator(Evaluator.t()) :: :ok
-  def terminate_evaluator(evaluator) do
-    DynamicSupervisor.terminate_child(@name, evaluator)
+  @spec terminate_evaluator(pid(), Evaluator.t()) :: :ok
+  def terminate_evaluator(supervisor, evaluator) do
+    DynamicSupervisor.terminate_child(supervisor, evaluator)
     :ok
   end
 end
diff --git a/lib/livebook/runtime/erl_dist/manager.ex b/lib/livebook/runtime/erl_dist/manager.ex
index 61672a943..45aa2fd14 100644
--- a/lib/livebook/runtime/erl_dist/manager.ex
+++ b/lib/livebook/runtime/erl_dist/manager.ex
@@ -125,9 +125,9 @@ defmodule Livebook.Runtime.ErlDist.Manager do
 
     Process.flag(:trap_exit, true)
 
-    {:ok, _} = ErlDist.EvaluatorSupervisor.start_link()
+    {:ok, evaluator_supervisor} = ErlDist.EvaluatorSupervisor.start_link()
     {:ok, io_forward_gl_pid} = ErlDist.IOForwardGL.start_link()
-    {:ok, _} = Task.Supervisor.start_link(name: CompletionTaskSupervisor)
+    {:ok, completion_supervisor} = Task.Supervisor.start_link()
 
     # Set `ignore_module_conflict` only for the Manager lifetime.
     initial_ignore_module_conflict = Code.compiler_options()[:ignore_module_conflict]
@@ -143,6 +143,8 @@ defmodule Livebook.Runtime.ErlDist.Manager do
      %{
        owner: nil,
        evaluators: %{},
+       evaluator_supervisor: evaluator_supervisor,
+       completion_supervisor: completion_supervisor,
        initial_ignore_module_conflict: initial_ignore_module_conflict,
        original_standard_error: original_standard_error
      }}
@@ -243,7 +245,7 @@ defmodule Livebook.Runtime.ErlDist.Manager do
       Evaluator.request_completion_items(evaluator, send_to, ref, hint, evaluation_ref)
     else
       # Since there's no evaluator, we may as well get the completion items here.
-      Task.Supervisor.start_child(CompletionTaskSupervisor, fn ->
+      Task.Supervisor.start_child(state.completion_supervisor, fn ->
         binding = []
         env = :elixir.env_for_eval([])
         items = Livebook.Completion.get_completion_items(hint, binding, env)
@@ -258,7 +260,7 @@ defmodule Livebook.Runtime.ErlDist.Manager do
     if Map.has_key?(state.evaluators, container_ref) do
       state
     else
-      {:ok, evaluator} = ErlDist.EvaluatorSupervisor.start_evaluator()
+      {:ok, evaluator} = ErlDist.EvaluatorSupervisor.start_evaluator(state.evaluator_supervisor)
       Process.monitor(evaluator)
       %{state | evaluators: Map.put(state.evaluators, container_ref, evaluator)}
     end
@@ -267,7 +269,7 @@ defmodule Livebook.Runtime.ErlDist.Manager do
   defp discard_evaluator(state, container_ref) do
     case Map.fetch(state.evaluators, container_ref) do
       {:ok, evaluator} ->
-        ErlDist.EvaluatorSupervisor.terminate_evaluator(evaluator)
+        ErlDist.EvaluatorSupervisor.terminate_evaluator(state.evaluator_supervisor, evaluator)
         %{state | evaluators: Map.delete(state.evaluators, container_ref)}
 
       :error ->