Separate append server as gen_server callback module

src/machi_flu1.erl

@@ -21,7 +21,9 @@
 %% @doc The Machi FLU file server + file location sequencer.
 %%
 %% This module implements only the Machi FLU file server and its
-%% implicit sequencer.  
+%% implicit sequencer together with listener, append server,
+%% file management and file proxy processes.
+
 %% Please see the EDoc "Overview" for details about the FLU as a
 %% primitive file server process vs. the larger Machi design of a FLU
 %% as a sequencer + file server + chain manager group of processes.
@@ -54,27 +56,16 @@
 
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
+-export([timing_demo_test_COMMENTED_/0, sort_2lines/2]). % Just to suppress warning
 -endif. % TEST
 
 -export([start_link/1, stop/1,
          update_wedge_state/3, wedge_myself/2]).
--export([make_projection_server_regname/1]).
+-export([make_projection_server_regname/1,
+         ets_table_name/1]).
 %% TODO: remove or replace in OTP way after gen_*'ified
--export([main2/4, run_append_server/2,
+-export([main2/4]).
-         current_state/1, format_state/1]).
 
--record(state, {
-          flu_name        :: atom(),
-          proj_store      :: pid(),
-          witness = false :: boolean(),
-          append_pid      :: pid(),
-          wedged = true   :: boolean(),
-          etstab          :: ets:tid(),
-          epoch_id        :: 'undefined' | machi_dt:epoch_id(),
-          props = []      :: list()  % proplist
-         }).
-
--define(SERVER_CMD_READ_TIMEOUT, 600*1000).
 -define(INIT_TIMEOUT, 60*1000).
 
 start_link([{FluName, TcpPort, DataDir}|Rest])
@@ -97,32 +88,15 @@ stop(Pid) when is_pid(Pid) ->
     end.
 
 update_wedge_state(PidSpec, Boolean, EpochId)
-  when (Boolean == true orelse Boolean == false), is_tuple(EpochId) ->
+  when is_boolean(Boolean), is_tuple(EpochId) ->
-    PidSpec ! {wedge_state_change, Boolean, EpochId}.
+    gen_server:cast(PidSpec, {wedge_state_change, Boolean, EpochId}).
 
 wedge_myself(PidSpec, EpochId)
   when is_tuple(EpochId) ->
-    PidSpec ! {wedge_myself, EpochId}.
+    gen_server:cast(PidSpec, {wedge_myself, EpochId}).
-
-current_state(PidSpec) ->
-    PidSpec ! {current_state, self()},
-    %% TODO: Not so rubust f(^^;)
-    receive
-        Res -> Res
-    after
-        60*1000 -> {error, timeout}
-    end.
-
-format_state(State) ->
-    Fields = record_info(fields, state),
-    [_Name | Values] = tuple_to_list(State),
-    lists:zip(Fields, Values).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-ets_table_name(FluName) when is_atom(FluName) ->
-    list_to_atom(atom_to_list(FluName) ++ "_epoch").
-
 main2(FluName, TcpPort, DataDir, Props) ->
     {SendAppendPidToProj_p, ProjectionPid} =
         case proplists:get_value(projection_store_registered_name, Props) of
@@ -149,23 +123,15 @@ main2(FluName, TcpPort, DataDir, Props) ->
                 {true, undefined}
         end,
     Witness_p = proplists:get_value(witness_mode, Props, false),
-    
+
-    S0 = #state{flu_name=FluName,
+    {ok, AppendPid} = start_append_server(FluName, Witness_p, Wedged_p, EpochId),
-                proj_store=ProjectionPid,
-                wedged=Wedged_p,
-                witness=Witness_p,
-                etstab=ets_table_name(FluName),
-                epoch_id=EpochId,
-                props=Props},
-    {ok, AppendPid} = start_append_server(S0, self()),
     if SendAppendPidToProj_p ->
-            machi_projection_store:set_wedge_notify_pid(ProjectionPid,
+            machi_projection_store:set_wedge_notify_pid(ProjectionPid, AppendPid);
-                                                        AppendPid);
        true ->
             ok
     end,
-    S1 = S0#state{append_pid=AppendPid},
+    {ok, ListenerPid} = start_listen_server(FluName, TcpPort, Witness_p, DataDir,
-    {ok, ListenerPid} = start_listen_server(TcpPort, DataDir, S1),
+                                            ets_table_name(FluName), ProjectionPid),
     %% io:format(user, "Listener started: ~w~n", [{FluName, ListenerPid}]),
 
     Config_e = machi_util:make_config_filename(DataDir, "unused"),
@@ -176,135 +142,23 @@ main2(FluName, TcpPort, DataDir, Props) ->
     ok = filelib:ensure_dir(Projection_e),
 
     put(flu_flu_name, FluName),
-    put(flu_append_pid, S1#state.append_pid),
+    put(flu_append_pid, AppendPid),
     put(flu_projection_pid, ProjectionPid),
     put(flu_listen_pid, ListenerPid),
     proc_lib:init_ack({ok, self()}),
 
     receive killme -> ok end,
-    (catch exit(S1#state.append_pid, kill)),
+    (catch exit(AppendPid, kill)),
     (catch exit(ProjectionPid, kill)),
     (catch exit(ListenerPid, kill)),
     ok.
 
-start_append_server(S, AckPid) ->
+start_append_server(FluName, Witness_p, Wedged_p, EpochId) ->
-    proc_lib:start_link(?MODULE, run_append_server, [AckPid, S], ?INIT_TIMEOUT).
+    machi_flu1_subsup:start_append_server(FluName, Witness_p, Wedged_p, EpochId).
 
-start_listen_server(TcpPort, DataDir,
+start_listen_server(FluName, TcpPort, Witness_p, DataDir, EtsTab, ProjectionPid) ->
-                    #state{flu_name=FluName, witness=Witness, etstab=EtsTab,
+    machi_flu1_subsup:start_listener(FluName, TcpPort, Witness_p, DataDir,
-                           proj_store=ProjStore}=_S) ->
+                                     EtsTab, ProjectionPid).
-    machi_listener_sup:start_listener(FluName, TcpPort, Witness, DataDir,
-                                      EtsTab, ProjStore).
-
-run_append_server(FluPid, #state{flu_name=Name,
-                                 wedged=Wedged_p,epoch_id=EpochId}=S) ->
-    %% Reminder: Name is the "main" name of the FLU, i.e., no suffix
-    register(Name, self()),
-    TID = ets:new(ets_table_name(Name),
-                  [set, protected, named_table, {read_concurrency, true}]),
-    ets:insert(TID, {epoch, {Wedged_p, EpochId}}),
-    proc_lib:init_ack({ok, self()}),
-    append_server_loop(FluPid, S#state{etstab=TID}).
-
-append_server_loop(FluPid, #state{wedged=Wedged_p,
-                                  witness=Witness_p,
-                                  epoch_id=OldEpochId, flu_name=FluName}=S) ->
-    receive
-        {seq_append, From, _N, _L, _Prefix, _Chunk, _CSum, _Extra, _EpochID}
-          when Witness_p ->
-            %% The FLU's machi_flu1_net_server process ought to filter all
-            %% witness states, but we'll keep this clause for extra
-            %% paranoia.
-            From ! witness,
-            append_server_loop(FluPid, S);
-        {seq_append, From, _N, _L, _Prefix, _Chunk, _CSum, _Extra, _EpochID}
-          when Wedged_p ->
-            From ! wedged,
-            append_server_loop(FluPid, S);
-        {seq_append, From, CoC_Namespace, CoC_Locator,
-         Prefix, Chunk, CSum, Extra, EpochID} ->
-            %% Old is the one from our state, plain old 'EpochID' comes
-            %% from the client.
-            _ = case OldEpochId == EpochID of
-                true ->
-                    spawn(fun() -> 
-                        append_server_dispatch(From, CoC_Namespace, CoC_Locator,
-                                               Prefix, Chunk, CSum, Extra,
-                                               FluName, EpochID) 
-                    end);
-                false ->
-                    From ! {error, bad_epoch}
-            end,
-            append_server_loop(FluPid, S);
-        {wedge_myself, WedgeEpochId} ->
-            if not Wedged_p andalso WedgeEpochId == OldEpochId ->
-                    true = ets:insert(S#state.etstab,
-                                      {epoch, {true, OldEpochId}}),
-                    %% Tell my chain manager that it might want to react to
-                    %% this new world.
-                    Chmgr = machi_chain_manager1:make_chmgr_regname(FluName),
-                    spawn(fun() ->
-                            catch machi_chain_manager1:trigger_react_to_env(Chmgr)
-                          end),
-                    append_server_loop(FluPid, S#state{wedged=true});
-               true ->
-                    append_server_loop(FluPid, S)
-            end;
-        {wedge_state_change, Boolean, {NewEpoch, _}=NewEpochId} ->
-            OldEpoch = case OldEpochId of {OldE, _} -> OldE;
-                                          undefined -> -1
-                       end,
-            if NewEpoch >= OldEpoch ->
-                    true = ets:insert(S#state.etstab,
-                                      {epoch, {Boolean, NewEpochId}}),
-                    append_server_loop(FluPid, S#state{wedged=Boolean,
-                                                       epoch_id=NewEpochId});
-               true ->
-                    append_server_loop(FluPid, S)
-            end;
-        {wedge_status, FromPid} ->
-            #state{wedged=Wedged_p, epoch_id=EpochId} = S,
-            FromPid ! {wedge_status_reply, Wedged_p, EpochId},
-            append_server_loop(FluPid, S);
-        {current_state, FromPid} ->
-            FromPid ! S;
-        Else ->
-            io:format(user, "append_server_loop: WHA? ~p\n", [Else]),
-            append_server_loop(FluPid, S)
-    end.
-
-append_server_dispatch(From, CoC_Namespace, CoC_Locator,
-                       Prefix, Chunk, CSum, Extra, FluName, EpochId) ->
-    Result = case handle_append(CoC_Namespace, CoC_Locator,
-                                Prefix, Chunk, CSum, Extra, FluName, EpochId) of
-        {ok, File, Offset} ->
-            {assignment, Offset, File};
-        Other ->
-            Other
-    end,
-    From ! Result,
-    exit(normal).
-
-handle_append(_N, _L, _Prefix, <<>>, _Csum, _Extra, _FluName, _EpochId) ->
-    {error, bad_arg};
-handle_append(CoC_Namespace, CoC_Locator,
-              Prefix, Chunk, Csum, Extra, FluName, EpochId) ->
-    CoC = {coc, CoC_Namespace, CoC_Locator},
-    Res = machi_flu_filename_mgr:find_or_make_filename_from_prefix(
-            FluName, EpochId, {prefix, Prefix}, CoC),
-    case Res of
-        {file, F} ->
-            case machi_flu_metadata_mgr:start_proxy_pid(FluName, {file, F}) of
-                {ok, Pid} ->
-                    {Tag, CS} = machi_util:unmake_tagged_csum(Csum),
-                    Meta = [{client_csum_tag, Tag}, {client_csum, CS}],
-                    machi_file_proxy:append(Pid, Meta, Extra, Chunk);
-                {error, trimmed} = E ->
-                    E
-            end;
-        Error ->
-            Error
-    end.
 
 %% This is the name of the projection store that is spawned by the
 %% *flu*, for use primarily in testing scenarios.  In normal use, we
@@ -316,6 +170,8 @@ handle_append(CoC_Namespace, CoC_Locator,
 make_projection_server_regname(BaseName) ->
     list_to_atom(atom_to_list(BaseName) ++ "_pstore").
 
+ets_table_name(FluName) when is_atom(FluName) ->
+    list_to_atom(atom_to_list(FluName) ++ "_epoch").
 
 -ifdef(TEST).
 
@@ -357,7 +213,7 @@ timing_demo_test2() ->
                      lists:foldl(fun(X, _) ->
                                          B = machi_checksums:encode_csum_file_entry_hex(X, 100, CSum),
                                          %% file:write(ZZZ, [B, 10]),
-                                         machi_checksums:decode_csum_file_entry_hex(list_to_binary(B))
+                                         decode_csum_file_entry_hex(list_to_binary(B))
                                  end, x, Xs)
              end),
     io:format(user, "~.3f sec\n", [HexUSec / 1000000]),

src/machi_flu1_append_server.erl

@@ -0,0 +1,188 @@
+%% -------------------------------------------------------------------
+%%
+%% Copyright (c) 2007-2015 Basho Technologies, Inc.  All Rights Reserved.
+%%
+%% This file is provided to you under the Apache License,
+%% Version 2.0 (the "License"); you may not use this file
+%% except in compliance with the License.  You may obtain
+%% a copy of the License at
+%%
+%%   http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing,
+%% software distributed under the License is distributed on an
+%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%% KIND, either express or implied.  See the License for the
+%% specific language governing permissions and limitations
+%% under the License.
+%%
+%% -------------------------------------------------------------------
+
+%% @doc Machi FLU1 append serialization server process
+
+-module(machi_flu1_append_server).
+
+-behavior(gen_server).
+
+-include("machi.hrl").
+-include("machi_projection.hrl").
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+-endif. % TEST
+
+-export([start_link/4]).
+
+-export([init/1]).
+-export([handle_call/3, handle_cast/2, handle_info/2,
+         terminate/2, code_change/3]).
+
+-export([current_state/1, format_state/1]).
+
+-record(state, {
+          flu_name        :: atom(),
+          witness = false :: boolean(),
+          wedged = true   :: boolean(),
+          etstab          :: ets:tid(),
+          epoch_id        :: 'undefined' | machi_dt:epoch_id()
+         }).
+
+-define(INIT_TIMEOUT, 60*1000).
+-define(CALL_TIMEOUT, 60*1000).
+
+-spec start_link(pv1_server(), boolean(), boolean(),
+                 undefined | machi_dt:epoch_id()) -> {ok, pid()}.
+start_link(Fluname, Witness_p, Wedged_p, EpochId) ->
+    %% Reminder: Name is the "main" name of the FLU, i.e., no suffix
+    gen_server:start_link({local, Fluname},
+                          ?MODULE, [Fluname, Witness_p, Wedged_p, EpochId],
+                          [{timeout, ?INIT_TIMEOUT}]).
+
+-spec current_state(atom() | pid()) -> term().
+current_state(PidSpec) ->
+    gen_server:call(PidSpec, current_state, ?CALL_TIMEOUT).
+
+format_state(State) ->
+    Fields = record_info(fields, state),
+    [_Name | Values] = tuple_to_list(State),
+    lists:zip(Fields, Values).
+
+
+init([Fluname, Witness_p, Wedged_p, EpochId]) ->
+    TID = ets:new(machi_flu1:ets_table_name(Fluname),
+                  [set, protected, named_table, {read_concurrency, true}]),
+    ets:insert(TID, {epoch, {Wedged_p, EpochId}}),
+    {ok, #state{flu_name=Fluname, witness=Witness_p, wedged=Wedged_p,
+                etstab=TID, epoch_id=EpochId}}.
+
+handle_call({seq_append, _From2, _N, _L, _Prefix, _Chunk, _CSum, _Extra, _EpochID},
+            _From, #state{witness=true}=S) ->
+    %% The FLU's machi_flu1_net_server process ought to filter all
+    %% witness states, but we'll keep this clause for extra
+    %% paranoia.
+    {reply, witness, S};
+handle_call({seq_append, _From2, _N, _L, _Prefix, _Chunk, _CSum, _Extra, _EpochID},
+            _From, #state{wedged=true}=S) ->
+    {reply, wedged, S};
+handle_call({seq_append, _From2, CoC_Namespace, CoC_Locator,
+             Prefix, Chunk, CSum, Extra, EpochID},
+            From, #state{flu_name=FluName, epoch_id=OldEpochId}=S) ->
+    %% Old is the one from our state, plain old 'EpochID' comes
+    %% from the client.
+    _ = case OldEpochId of
+            EpochID ->
+                spawn(fun() ->
+                              append_server_dispatch(From, CoC_Namespace, CoC_Locator,
+                                                     Prefix, Chunk, CSum, Extra,
+                                                     FluName, EpochID)
+                      end),
+                {noreply, S};
+            _ ->
+                {reply, {error, bad_epoch}, S}
+        end;
+%% TODO: Who sends this message?
+handle_call(wedge_status, _From,
+            #state{wedged=Wedged_p, epoch_id=EpochId} = S) ->
+    {reply, {wedge_status_reply, Wedged_p, EpochId}, S};
+handle_call(current_state, _From, S) ->
+    {reply, S, S};
+handle_call(Else, From, S) ->
+    io:format(user, "~s:handle_call: WHA? from=~w ~w\n", [?MODULE, From, Else]),
+    {noreply, S}.
+
+handle_cast({wedge_myself, WedgeEpochId},
+            #state{flu_name=FluName, wedged=Wedged_p, epoch_id=OldEpochId}=S) ->
+    if not Wedged_p andalso WedgeEpochId == OldEpochId ->
+            true = ets:insert(S#state.etstab,
+                              {epoch, {true, OldEpochId}}),
+            %% Tell my chain manager that it might want to react to
+            %% this new world.
+            Chmgr = machi_chain_manager1:make_chmgr_regname(FluName),
+            spawn(fun() ->
+                          catch machi_chain_manager1:trigger_react_to_env(Chmgr)
+                  end),
+            {noreply, S#state{wedged=true}};
+       true ->
+            {noreply, S}
+    end;
+handle_cast({wedge_state_change, Boolean, {NewEpoch, _}=NewEpochId},
+            #state{epoch_id=OldEpochId}=S) ->
+    OldEpoch = case OldEpochId of {OldE, _} -> OldE;
+                   undefined -> -1
+               end,
+    if NewEpoch >= OldEpoch ->
+            true = ets:insert(S#state.etstab,
+                              {epoch, {Boolean, NewEpochId}}),
+            {noreply, S#state{wedged=Boolean, epoch_id=NewEpochId}};
+       true ->
+            {noreply, S}
+    end;
+handle_cast(Else, S) ->
+    io:format(user, "~s:handle_cast: WHA? ~p\n", [?MODULE, Else]),
+    {noreply, S}.
+
+handle_info(Else, S) ->
+    io:format(user, "~s:handle_info: WHA? ~p\n", [?MODULE, Else]),
+    {noreply, S}.
+
+terminate(normal, _S) ->
+    ok;
+terminate(Reason, _S) ->
+    lager:warning("~s:terminate: ~w", [?MODULE, Reason]),
+    ok.
+
+code_change(_OldVsn, S, _Extra) ->
+    {ok, S}.
+
+append_server_dispatch(From, CoC_Namespace, CoC_Locator,
+                       Prefix, Chunk, CSum, Extra, FluName, EpochId) ->
+    Result = case handle_append(CoC_Namespace, CoC_Locator,
+                                Prefix, Chunk, CSum, Extra, FluName, EpochId) of
+        {ok, File, Offset} ->
+            {assignment, Offset, File};
+        Other ->
+            Other
+    end,
+    _ = gen_server:reply(From, Result),
+    exit(normal).
+
+handle_append(_N, _L, _Prefix, <<>>, _Csum, _Extra, _FluName, _EpochId) ->
+    {error, bad_arg};
+handle_append(CoC_Namespace, CoC_Locator,
+              Prefix, Chunk, Csum, Extra, FluName, EpochId) ->
+    CoC = {coc, CoC_Namespace, CoC_Locator},
+    Res = machi_flu_filename_mgr:find_or_make_filename_from_prefix(
+            FluName, EpochId, {prefix, Prefix}, CoC),
+    case Res of
+        {file, F} ->
+            case machi_flu_metadata_mgr:start_proxy_pid(FluName, {file, F}) of
+                {ok, Pid} ->
+                    {Tag, CS} = machi_util:unmake_tagged_csum(Csum),
+                    Meta = [{client_csum_tag, Tag}, {client_csum, CS}],
+                    machi_file_proxy:append(Pid, Meta, Extra, Chunk);
+                {error, trimmed} = E ->
+                    E
+            end;
+        Error ->
+            Error
+    end.

src/machi_flu1_net_server.erl

@@ -355,16 +355,15 @@ do_server_append_chunk2(CoC_Namespace, CoC_Locator,
         TaggedCSum = check_or_make_tagged_checksum(CSum_tag, Client_CSum,Chunk),
         R = {seq_append, self(), CoC_Namespace, CoC_Locator,
              Prefix, Chunk, TaggedCSum, ChunkExtra, EpochID},
-        FluName ! R,
+        case gen_server:call(FluName, R, 10*1000) of
-        receive
             {assignment, Offset, File} ->
                 Size = iolist_size(Chunk),
                 {ok, {Offset, Size, File}};
             witness ->
                 {error, bad_arg};
             wedged ->
-                {error, wedged}
+                {error, wedged};
-        after 10*1000 ->
+            {error, timeout} ->
                 {error, partition}
         end
     catch

src/machi_flu1_subsup.erl

@@ -0,0 +1,115 @@
+%% -------------------------------------------------------------------
+%%
+%% Copyright (c) 2007-2015 Basho Technologies, Inc.  All Rights Reserved.
+%%
+%% This file is provided to you under the Apache License,
+%% Version 2.0 (the "License"); you may not use this file
+%% except in compliance with the License.  You may obtain
+%% a copy of the License at
+%%
+%%   http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing,
+%% software distributed under the License is distributed on an
+%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%% KIND, either express or implied.  See the License for the
+%% specific language governing permissions and limitations
+%% under the License.
+%%
+%% -------------------------------------------------------------------
+
+%% @doc A supervisor to hold dynamic processes inside single
+%% FLU service, ranch listener and append server.
+
+%% TODO: This supervisor is maybe useless. First introduced for
+%% workaround to start listener dynamically in flu1 initialization
+%% phase.  Because `machi_flu_psup' is being blocked in flu1
+%% initialization time, adding a child to the supervisor leads to
+%% deadlock.  If initialization can be done only by static arguments,
+%% then this supervisor should be removed and added as a direct child
+%% of `machi_flu_psup'.
+
+-module(machi_flu1_subsup).
+-behaviour(supervisor).
+
+%% public API
+-export([start_link/1,
+         start_append_server/4,
+         stop_append_server/1,
+         start_listener/6,
+         stop_listener/1,
+         subsup_name/1,
+         listener_name/1]).
+
+%% supervisor callback
+-export([init/1]).
+
+-include("machi_projection.hrl").
+
+-define(SHUTDOWN, 5000).
+-define(BACKLOG, 8192).
+
+-spec start_link(pv1_server()) -> {ok, pid()}.
+start_link(FluName) ->
+    supervisor:start_link({local, subsup_name(FluName)}, ?MODULE, []).
+
+-spec start_append_server(pv1_server(), boolean(), boolean(),
+                          undefined | machi_dt:epoch_id()) ->
+                                 {ok, pid()}.
+start_append_server(FluName, Witness_p, Wedged_p, EpochId) ->
+    supervisor:start_child(subsup_name(FluName),
+                           append_server_spec(FluName, Witness_p, Wedged_p, EpochId)).
+
+-spec stop_append_server(pv1_server()) -> ok.
+stop_append_server(FluName) ->
+    SubSup = listener_name(FluName),
+    ok = supervisor:terminate_child(SubSup, FluName),
+    ok = supervisor:delete_child(SubSup, FluName).
+
+-spec start_listener(pv1_server(), inet:port_number(), boolean(),
+                     string(), ets:tab(), atom() | pid()) -> {ok, pid()}.
+start_listener(FluName, TcpPort, Witness, DataDir, EpochTab, ProjStore) ->
+    supervisor:start_child(subsup_name(FluName),
+                           listener_spec(FluName, TcpPort, Witness, DataDir,
+                                         EpochTab, ProjStore)).
+
+-spec stop_listener(pv1_server()) -> ok.
+stop_listener(FluName) ->
+    SupName = subsup_name(FluName),
+    ListenerName = listener_name(FluName),
+    ok = supervisor:terminate_child(SupName, ListenerName),
+    ok = supervisor:delete_child(SupName, ListenerName).
+
+-spec subsup_name(pv1_server()) -> atom().
+subsup_name(FluName) when is_atom(FluName) ->
+    list_to_atom(atom_to_list(FluName) ++ "_flu1_subsup").
+
+-spec listener_name(pv1_server()) -> atom().
+listener_name(FluName) ->
+    list_to_atom(atom_to_list(FluName) ++ "_listener").
+
+%% Supervisor callback
+
+init([]) ->
+    SupFlags = {one_for_all, 1000, 10},
+    {ok, {SupFlags, []}}.
+
+%% private
+
+-spec listener_spec(pv1_server(), inet:port_number(), boolean(),
+                    string(), ets:tab(), atom() | pid()) -> supervisor:child_spec().
+listener_spec(FluName, TcpPort, Witness, DataDir, EpochTab, ProjStore) ->
+    ListenerName = listener_name(FluName),
+    NbAcceptors = 100,
+    TcpOpts = [{port, TcpPort}, {backlog, ?BACKLOG}],
+    NetServerOpts = [FluName, Witness, DataDir, EpochTab, ProjStore],
+    ranch:child_spec(ListenerName, NbAcceptors,
+                     ranch_tcp, TcpOpts,
+                     machi_flu1_net_server, NetServerOpts).
+
+-spec append_server_spec(pv1_server(), boolean(), boolean(),
+                         undefined | machi_dt:epoch_id()) -> supervisor:child_spec().
+append_server_spec(FluName, Witness_p, Wedged_p, EpochId) ->
+    {FluName, {machi_flu1_append_server, start_link,
+               [FluName, Witness_p, Wedged_p, EpochId]},
+     permanent, ?SHUTDOWN, worker, [machi_flu1_append_server]}.

src/machi_flu_psup.erl

@@ -143,9 +143,9 @@ init([FluName, TcpPort, DataDir, Props0]) ->
 
     FProxySupSpec = machi_file_proxy_sup:child_spec(FluName),
 
-    ListenerSupSpec = {machi_listener_sup:make_listener_sup_name(FluName),
+    Flu1SubSupSpec = {machi_flu1_subsup:subsup_name(FluName),
-                       {machi_listener_sup, start_link, [FluName]},
+                      {machi_flu1_subsup, start_link, [FluName]},
-                       permanent, ?SHUTDOWN, supervisor, []},
+                      permanent, ?SHUTDOWN, supervisor, []},
 
     FluSpec = {FluName,
                {machi_flu1, start_link,
@@ -155,7 +155,7 @@ init([FluName, TcpPort, DataDir, Props0]) ->
     {ok, {SupFlags, [
             ProjSpec, FitnessSpec, MgrSpec,
             FProxySupSpec, FNameMgrSpec, MetaSupSpec,
-            ListenerSupSpec, FluSpec]}}.
+            Flu1SubSupSpec, FluSpec]}}.
 
 make_flu_regname(FluName) when is_atom(FluName) ->
     FluName.

src/machi_listener_sup.erl

@@ -1,89 +0,0 @@
-%% -------------------------------------------------------------------
-%%
-%% Copyright (c) 2007-2015 Basho Technologies, Inc.  All Rights Reserved.
-%%
-%% This file is provided to you under the Apache License,
-%% Version 2.0 (the "License"); you may not use this file
-%% except in compliance with the License.  You may obtain
-%% a copy of the License at
-%%
-%%   http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing,
-%% software distributed under the License is distributed on an
-%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-%% KIND, either express or implied.  See the License for the
-%% specific language governing permissions and limitations
-%% under the License.
-%%
-%% -------------------------------------------------------------------
-
-%% @doc A supervisor to hold ranch listener for sigle FLU.
-%% It holds at most one child worker.
-
-%% TODO: This supervisor is maybe useless. First introduced for
-%% workaround to start listener dynamically in flu1 initialization
-%% time.  Because psup is being blocked in flu1 initialization time,
-%% adding a child to psup leads to deadlock.  If initialization can be
-%% done only by static arguments, then this supervisor should be
-%% removed and added as a direct child of `machi_flu_psup'.
-
--module(machi_listener_sup).
--behaviour(supervisor).
-
-%% public API
--export([start_link/1,
-         start_listener/6,
-         stop_listener/1,
-         make_listener_sup_name/1,
-         make_listener_name/1]).
-
-%% supervisor callback
--export([init/1]).
-
--include("machi_projection.hrl").
-
--define(BACKLOG, 8192).
-
--spec start_link(pv1_server()) -> {ok, pid()}.
-start_link(FluName) ->
-    supervisor:start_link({local, make_listener_sup_name(FluName)}, ?MODULE, []).
-
--spec start_listener(pv1_server(), inet:port_number(), boolean(),
-                     string(), ets:tab(), atom() | pid()) -> {ok, pid()}.
-start_listener(FluName, TcpPort, Witness, DataDir, EpochTab, ProjStore) ->
-    supervisor:start_child(make_listener_sup_name(FluName),
-                           child_spec(FluName, TcpPort, Witness, DataDir,
-                                      EpochTab, ProjStore)).
-
--spec stop_listener(pv1_server()) -> ok.
-stop_listener(FluName) ->
-    SupName = make_listener_sup_name(FluName),
-    ListenerName = make_listener_name(FluName),
-    ok = supervisor:terminate_child(SupName, ListenerName),
-    ok = supervisor:delete_child(SupName, ListenerName).
-
--spec make_listener_name(pv1_server()) -> atom().
-make_listener_sup_name(FluName) when is_atom(FluName) ->
-    list_to_atom(atom_to_list(FluName) ++ "_listener_sup").
-
--spec make_listener_sup_name(pv1_server()) -> atom().
-make_listener_name(FluName) ->
-    list_to_atom(atom_to_list(FluName) ++ "_listener").
-
-%% Supervisor callback
-
-init([]) ->
-    SupFlags = {one_for_one, 1000, 10},
-    {ok, {SupFlags, []}}.
-
--spec child_spec(pv1_server(), inet:port_number(), boolean(),
-                 string(), ets:tab(), atom() | pid()) -> supervisor:child_spec().
-child_spec(FluName, TcpPort, Witness, DataDir, EpochTab, ProjStore) ->
-    ListenerName = make_listener_name(FluName),
-    NbAcceptors = 100,
-    TcpOpts = [{port, TcpPort}, {backlog, ?BACKLOG}],
-    NetServerOpts = [FluName, Witness, DataDir, EpochTab, ProjStore],
-    ranch:child_spec(ListenerName, NbAcceptors,
-                     ranch_tcp, TcpOpts,
-                     machi_flu1_net_server, NetServerOpts).