1 files changed, 49 insertions, 0 deletions
diff --git a/lib/pleroma/gun/connection_pool/worker_supervisor.ex b/lib/pleroma/gun/connection_pool/worker_supervisor.ex
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+++ b/lib/pleroma/gun/connection_pool/worker_supervisor.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Gun.ConnectionPool.WorkerSupervisor do
+  @moduledoc "Supervisor for pool workers. Does not do anything except enforce max connection limit"
+
+  use DynamicSupervisor
+
+  def start_link(opts) do
+    DynamicSupervisor.start_link(__MODULE__, opts, name: __MODULE__)
+  end
+
+  def init(_opts) do
+    DynamicSupervisor.init(
+      strategy: :one_for_one,
+      max_children: Pleroma.Config.get([:connections_pool, :max_connections])
+    )
+  end
+
+  def start_worker(opts, retry \\ false) do
+    case DynamicSupervisor.start_child(__MODULE__, {Pleroma.Gun.ConnectionPool.Worker, opts}) do
+      {:error, :max_children} ->
+        if retry or free_pool() == :error do
+          :telemetry.execute([:pleroma, :connection_pool, :provision_failure], %{opts: opts})
+          {:error, :pool_full}
+        else
+          start_worker(opts, true)
+        end
+
+      res ->
+        res
+    end
+  end
+
+  defp free_pool do
+    wait_for_reclaimer_finish(Pleroma.Gun.ConnectionPool.Reclaimer.start_monitor())
+  end
+
+  defp wait_for_reclaimer_finish({pid, mon}) do
+    receive do
+      {:DOWN, ^mon, :process, ^pid, :no_unused_conns} ->
+        :error
+
+      {:DOWN, ^mon, :process, ^pid, :normal} ->
+        :ok
+    end
+  end
+end