1 files changed, 85 insertions, 0 deletions
diff --git a/lib/pleroma/gun/connection_pool/reclaimer.ex b/lib/pleroma/gun/connection_pool/reclaimer.ex
new file mode 100644
index 000000000..cea800882
--- /dev/null
+++ b/lib/pleroma/gun/connection_pool/reclaimer.ex
@@ -0,0 +1,85 @@
+defmodule Pleroma.Gun.ConnectionPool.Reclaimer do
+  use GenServer, restart: :temporary
+
+  @registry Pleroma.Gun.ConnectionPool
+
+  def start_monitor do
+    pid =
+      case :gen_server.start(__MODULE__, [], name: {:via, Registry, {@registry, "reclaimer"}}) do
+        {:ok, pid} ->
+          pid
+
+        {:error, {:already_registered, pid}} ->
+          pid
+      end
+
+    {pid, Process.monitor(pid)}
+  end
+
+  @impl true
+  def init(_) do
+    {:ok, nil, {:continue, :reclaim}}
+  end
+
+  @impl true
+  def handle_continue(:reclaim, _) do
+    max_connections = Pleroma.Config.get([:connections_pool, :max_connections])
+
+    reclaim_max =
+      [:connections_pool, :reclaim_multiplier]
+      |> Pleroma.Config.get()
+      |> Kernel.*(max_connections)
+      |> round
+      |> max(1)
+
+    :telemetry.execute([:pleroma, :connection_pool, :reclaim, :start], %{}, %{
+      max_connections: max_connections,
+      reclaim_max: reclaim_max
+    })
+
+    # :ets.fun2ms(
+    # fn {_, {worker_pid, {_, used_by, crf, last_reference}}} when used_by == [] ->
+    #   {worker_pid, crf, last_reference} end)
+    unused_conns =
+      Registry.select(
+        @registry,
+        [
+          {{:_, :"$1", {:_, :"$2", :"$3", :"$4"}}, [{:==, :"$2", []}], [{{:"$1", :"$3", :"$4"}}]}
+        ]
+      )
+
+    case unused_conns do
+      [] ->
+        :telemetry.execute(
+          [:pleroma, :connection_pool, :reclaim, :stop],
+          %{reclaimed_count: 0},
+          %{
+            max_connections: max_connections
+          }
+        )
+
+        {:stop, :no_unused_conns, nil}
+
+      unused_conns ->
+        reclaimed =
+          unused_conns
+          |> Enum.sort(fn {_pid1, crf1, last_reference1}, {_pid2, crf2, last_reference2} ->
+            crf1 <= crf2 and last_reference1 <= last_reference2
+          end)
+          |> Enum.take(reclaim_max)
+
+        reclaimed
+        |> Enum.each(fn {pid, _, _} ->
+          DynamicSupervisor.terminate_child(Pleroma.Gun.ConnectionPool.WorkerSupervisor, pid)
+        end)
+
+        :telemetry.execute(
+          [:pleroma, :connection_pool, :reclaim, :stop],
+          %{reclaimed_count: Enum.count(reclaimed)},
+          %{max_connections: max_connections}
+        )
+
+        {:stop, :normal, nil}
+    end
+  end
+end