use poolboy for concurrent request execution

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/application.ex

@@ -41,8 +41,23 @@ defmodule EthereumJSONRPC.Application do
 
   defp add_ipc_client(children) do
     case Application.get_env(:ethereum_jsonrpc, :rpc_transport) do
-      :ipc -> [IPC.child_spec(path: Application.get_env(:ethereum_jsonrpc, :ipc_path)) | children]
-      _ -> children
+      :ipc ->
+        [
+          :poolboy.child_spec(:worker, poolboy_config(), path: Application.get_env(:ethereum_jsonrpc, :ipc_path))
+          | children
+        ]
+
+      _ ->
+        children
     end
   end
+
+  defp poolboy_config do
+    [
+      {:name, {:local, :ipc_worker}},
+      {:worker_module, IPC},
+      {:size, 10},
+      {:max_overflow, 5}
+    ]
+  end
 end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/ipc.ex

@@ -6,18 +6,8 @@ defmodule EthereumJSONRPC.IPC do
 
   # Server
 
-  def child_spec(opts) do
-    default = %{
-      id: __MODULE__,
-      start: {__MODULE__, :start_link, opts},
-      type: :worker
-    }
-
-    Supervisor.child_spec(default, [])
-  end
-
-  def start_link({:path, path}) do
-    GenServer.start_link(__MODULE__, [path: path, socket: nil], name: __MODULE__)
+  def start_link(opts) do
+    GenServer.start_link(__MODULE__, Keyword.merge(opts, socket: nil))
   end
 
   def init(state) do
@@ -72,8 +62,8 @@ defmodule EthereumJSONRPC.IPC do
 
   # Client
 
-  def json_rpc(payload, _opts) do
-    with {:ok, response} <- post(__MODULE__, Jason.encode!(payload)),
+  def request(pid, payload) do
+    with {:ok, response} <- post(pid, Jason.encode!(payload)),
          {:ok, decoded_body} <- Jason.decode(response) do
       case decoded_body do
         %{"error" => error} ->
@@ -97,4 +87,8 @@ defmodule EthereumJSONRPC.IPC do
       {:error, error} -> {:error, error}
     end
   end
+
+  def json_rpc(payload, _opts) do
+    :poolboy.transaction(:ipc_worker, fn pid -> request(pid, payload) end, 600_000)
+  end
 end

apps/ethereum_jsonrpc/mix.exs

@@ -91,7 +91,8 @@ defmodule EthereumJsonrpc.MixProject do
       {:websocket_client, "~> 1.3"},
       {:decimal, "~> 1.0"},
       {:decorator, "~> 1.2"},
-      {:hackney, "~> 1.15.2"}
+      {:hackney, "~> 1.15.2"},
+      {:poolboy, "~> 1.5.2"}
     ]
   end
 end