Support GenServer.ex & Supervisor.ex

Carbon copy from upstream, and adapted to gen_server.erl

Signed-off-by: Peter M <petermm@gmail.com>

libs/exavmlib/lib/CMakeLists.txt

@@ -39,12 +39,14 @@ set(ELIXIR_MODULES
     Enumerable.MapSet
     Enumerable.Range
     Exception
+    GenServer
     IO
     List
     Map
     MapSet
     Module
     Keyword
+    Supervisor
     Kernel
     Process
     Protocol.UndefinedError

libs/exavmlib/lib/GenServer.ex

@@ -0,0 +1,361 @@
+defmodule GenServer do
+  @callback init(init_arg :: term) ::
+              {:ok, state}
+              | {:ok, state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | :ignore
+              | {:stop, reason :: any}
+            when state: any
+
+  @callback handle_call(request :: term, from, state :: term) ::
+              {:reply, reply, new_state}
+              | {:reply, reply, new_state,
+                 timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:noreply, new_state}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:stop, reason, reply, new_state}
+              | {:stop, reason, new_state}
+            when reply: term, new_state: term, reason: term
+
+  @callback handle_cast(request :: term, state :: term) ::
+              {:noreply, new_state}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:stop, reason :: term, new_state}
+            when new_state: term
+
+  @callback handle_info(msg :: :timeout | term, state :: term) ::
+              {:noreply, new_state}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:stop, reason :: term, new_state}
+            when new_state: term
+
+  @callback handle_continue(continue_arg, state :: term) ::
+              {:noreply, new_state}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg}}
+              | {:stop, reason :: term, new_state}
+            when new_state: term, continue_arg: term
+
+  @callback terminate(reason, state :: term) :: term
+            when reason: :normal | :shutdown | {:shutdown, term} | term
+
+  @callback code_change(old_vsn, state :: term, extra :: term) ::
+              {:ok, new_state :: term}
+              | {:error, reason :: term}
+            when old_vsn: term | {:down, term}
+
+  @optional_callbacks code_change: 3,
+                      terminate: 2,
+                      handle_info: 2,
+                      handle_cast: 2,
+                      handle_call: 3,
+                      handle_continue: 2
+
+  @typedoc "Return values of `start*` functions"
+  @type on_start :: {:ok, pid} | :ignore | {:error, {:already_started, pid} | term}
+
+  @typedoc "The GenServer name"
+  @type name :: atom | {:global, term} | {:via, module, term}
+
+  @typedoc "Options used by the `start*` functions"
+  @type options :: [option]
+
+  @typedoc "Option values used by the `start*` functions"
+  @type option ::
+          {:debug, debug}
+          | {:name, name}
+          | {:timeout, timeout}
+          | {:spawn_opt, [Process.spawn_opt()]}
+          | {:hibernate_after, timeout}
+
+  @typedoc "Debug options supported by the `start*` functions"
+  @type debug :: [:trace | :log | :statistics | {:log_to_file, Path.t()}]
+
+  @typedoc """
+  The server reference.
+
+  This is either a plain PID or a value representing a registered name.
+  See the "Name registration" section of this document for more information.
+  """
+  @type server :: pid | name | {atom, node}
+
+  @typedoc """
+  Tuple describing the client of a call request.
+
+  `pid` is the PID of the caller and `tag` is a unique term used to identify the
+  call.
+  """
+  @type from :: {pid, tag :: term}
+
+  @doc false
+  defmacro __using__(opts) do
+    quote location: :keep, bind_quoted: [opts: opts] do
+      @behaviour GenServer
+
+      unless Module.has_attribute?(__MODULE__, :doc) do
+        @doc """
+        Returns a specification to start this module under a supervisor.
+
+        See `Supervisor`.
+        """
+      end
+
+      def child_spec(init_arg) do
+        default = %{
+          id: __MODULE__,
+          start: {__MODULE__, :start_link, [init_arg]}
+        }
+
+        Supervisor.child_spec(default, unquote(Macro.escape(opts)))
+      end
+
+      defoverridable child_spec: 1
+
+      # TODO: Remove this on v2.0
+      @before_compile GenServer
+
+      @doc false
+      def handle_call(msg, _from, state) do
+        proc =
+          case Process.info(self(), :registered_name) do
+            {_, []} -> self()
+            {_, name} -> name
+          end
+
+        # We do this to trick Dialyzer to not complain about non-local returns.
+        case :erlang.phash2(1, 1) do
+          0 ->
+            raise "attempted to call GenServer #{inspect(proc)} but no handle_call/3 clause was provided"
+
+          1 ->
+            {:stop, {:bad_call, msg}, state}
+        end
+      end
+
+      @doc false
+      def handle_info(msg, state) do
+        proc =
+          case Process.info(self(), :registered_name) do
+            {_, []} -> self()
+            {_, name} -> name
+          end
+
+        {:noreply, state}
+      end
+
+      @doc false
+      def handle_cast(msg, state) do
+        proc =
+          case Process.info(self(), :registered_name) do
+            {_, []} -> self()
+            {_, name} -> name
+          end
+
+        # We do this to trick Dialyzer to not complain about non-local returns.
+        case 0 do
+          0 ->
+            raise "attempted to cast GenServer #{inspect(proc)} but no handle_cast/2 clause was provided"
+
+          1 ->
+            {:stop, {:bad_cast, msg}, state}
+        end
+      end
+
+      @doc false
+      def terminate(_reason, _state) do
+        :ok
+      end
+
+      @doc false
+      def code_change(_old, state, _extra) do
+        {:ok, state}
+      end
+
+      defoverridable code_change: 3, terminate: 2, handle_info: 2, handle_cast: 2, handle_call: 3
+    end
+  end
+
+  defmacro __before_compile__(env) do
+    unless Module.defines?(env.module, {:init, 1}) do
+      message = """
+      function init/1 required by behaviour GenServer is not implemented \
+      (in module #{inspect(env.module)}).
+
+      We will inject a default implementation for now:
+
+          def init(init_arg) do
+            {:ok, init_arg}
+          end
+
+      You can copy the implementation above or define your own that converts \
+      the arguments given to GenServer.start_link/3 to the server state.
+      """
+
+      IO.warn(message, env)
+
+      quote do
+        @doc false
+        def init(init_arg) do
+          {:ok, init_arg}
+        end
+
+        defoverridable init: 1
+      end
+    end
+  end
+
+  @spec start_link(module, any, options) :: on_start
+  def start_link(module, init_arg, options \\ []) when is_atom(module) and is_list(options) do
+    do_start(:link, module, init_arg, options)
+  end
+
+  @spec start(module, any, options) :: on_start
+  def start(module, init_arg, options \\ []) when is_atom(module) and is_list(options) do
+    do_start(:nolink, module, init_arg, options)
+  end
+
+  defp do_start(:nolink, module, init_arg, options) do
+    case Keyword.pop(options, :name) do
+      {nil, opts} ->
+        # :gen.start(:gen_server, link, module, init_arg, opts)
+
+        # start(Module, Args, Options) ->
+        :gen_server.start(module, init_arg, opts)
+
+      {atom, opts} when is_atom(atom) ->
+        # :gen.start(:gen_server, link, {:local, atom}, module, init_arg, opts)
+
+        # start({local, Name}, Module, Args, Options) when is_atom(Name) ->
+        :gen_server.start({:local, atom}, module, init_arg, opts)
+
+      {other, _} ->
+        raise ArgumentError, """
+        expected :name option to be one of the following:
+
+          * nil
+          * atom
+          * {:global, term}
+          * {:via, module, term}
+
+        Got: #{inspect(other)}
+        """
+    end
+  end
+
+  defp do_start(:link, module, init_arg, options) do
+    case Keyword.pop(options, :name) do
+      {nil, opts} ->
+        # :gen.start(:gen_server, link, module, init_arg, opts)
+        # start(Module, Args, Options) ->
+        :gen_server.start_link(module, init_arg, opts)
+
+      {atom, opts} when is_atom(atom) ->
+        # :gen.start(:gen_server, link, {:local, atom}, module, init_arg, opts)
+
+        # start({local, Name}, Module, Args, Options) when is_atom(Name) ->
+        :gen_server.start_link({:local, atom}, module, init_arg, opts)
+
+      {other, _} ->
+        raise ArgumentError, """
+        expected :name option to be one of the following:
+
+          * nil
+          * atom
+          * {:global, term}
+          * {:via, module, term}
+
+        Got: #{inspect(other)}
+        """
+    end
+  end
+
+  @spec stop(server, reason :: term, timeout) :: :ok
+  def stop(server, reason \\ :normal, timeout \\ :infinity) do
+    :gen_server.stop(server, reason, timeout)
+    # case whereis(server) do
+    #   nil ->
+    #     exit({:noproc, {__MODULE__, :stop, [server, reason, timeout]}})
+
+    #   pid when pid == self() ->
+    #     exit({:calling_self, {__MODULE__, :stop, [server, reason, timeout]}})
+
+    #   pid ->
+    #     try do
+    #       :proc_lib.stop(pid, reason, timeout)
+    #     catch
+    #       :exit, err ->
+    #         exit({err, {__MODULE__, :stop, [server, reason, timeout]}})
+    #     end
+    # end
+  end
+
+  @spec call(server, term, timeout) :: term
+  def call(server, request, timeout \\ 5000)
+      when (is_integer(timeout) and timeout >= 0) or timeout == :infinity do
+    :gen_server.call(server, request, timeout)
+    # case :erlang.whereis(server) do
+    #   :undefined ->
+    #     exit({:noproc, {__MODULE__, :call, [server, request, timeout]}})
+
+    #   pid ->
+    #     try do
+    #       :gen_server.call(pid, request, timeout)
+    #     catch
+    #       :exit, reason ->
+    #         exit({reason, {__MODULE__, :call, [server, request, timeout]}})
+    #     else
+    #       {:ok, res} -> res
+    #     end
+    # end
+  end
+
+  @spec cast(server, term) :: :ok
+  def cast(server, request)
+
+  def cast({:global, name}, request) do
+    try do
+      :global.send(name, cast_msg(request))
+      :ok
+    catch
+      _, _ -> :ok
+    end
+  end
+
+  def cast({:via, mod, name}, request) do
+    try do
+      mod.send(name, cast_msg(request))
+      :ok
+    catch
+      _, _ -> :ok
+    end
+  end
+
+  def cast({name, node}, request) when is_atom(name) and is_atom(node),
+    do: do_send({name, node}, cast_msg(request))
+
+  def cast(dest, request) when is_atom(dest) or is_pid(dest), do: do_send(dest, cast_msg(request))
+
+  defp cast_msg(req) do
+    {:"$gen_cast", req}
+  end
+
+  defp do_send(dest, msg) do
+    try do
+      send(dest, msg)
+      :ok
+    catch
+      _, _ -> :ok
+    end
+  end
+
+  @spec reply(from, term) :: :ok
+  def reply(client, reply) do
+    :gen_server.reply(client, reply)
+  end
+
+  @doc false
+  def format_report(%{
+        label: {GenServer, :no_handle_info},
+        report: %{module: mod, message: msg, name: proc}
+      }) do
+    {~c"~p ~p received unexpected message in handle_info/2: ~p~n", [mod, proc, msg]}
+  end
+end