Merge pull request #529 from rabbitmq/add-ra-aux_command-3

ra: Add `aux_command/3`

Author: kjnilsson

src/ra.erl

@@ -77,6 +77,7 @@
          transfer_leadership/2,
          %% auxiliary commands
          aux_command/2,
+         aux_command/3,
          cast_aux_command/2,
          register_external_log_reader/1,
          member_overview/1,
@@ -1172,6 +1173,15 @@ transfer_leadership(ServerId, TargetServerId) ->
 aux_command(ServerRef, Cmd) ->
     gen_statem:call(ServerRef, {aux_command, Cmd}).
 
+%% @doc Executes (using a call) an auxiliary command that the state machine can handle.
+%%
+%% @param ServerId the Ra server(s) to send the query to
+%% @param Command an arbitrary term that the state machine can handle
+%% @end
+-spec aux_command(ra_server_id(), term(), timeout()) -> term().
+aux_command(ServerRef, Cmd, Timeout) ->
+    gen_statem:call(ServerRef, {aux_command, Cmd}, Timeout).
+
 %% @doc Executes (using a cast) an auxiliary command that the state machine can handle.
 %%
 %% @param ServerId the Ra server(s) to send the query to

test/ra_machine_int_SUITE.erl

@@ -51,6 +51,7 @@ all_tests() ->
      aux_command,
      aux_command_v2,
      aux_command_v1_and_v2,
+     aux_command_timeout,
      aux_monitor_effect,
      aux_and_machine_monitor_same_process,
      aux_and_machine_monitor_same_node,
@@ -810,6 +811,37 @@ aux_command_v1_and_v2(Config) ->
     ra:delete_cluster(Cluster),
     ok.
 
+aux_command_timeout(Config) ->
+    ClusterName = ?config(cluster_name, Config),
+    ServerId1 = ?config(server_id, Config),
+    Cluster = [ServerId1,
+               ?config(server_id2, Config),
+               ?config(server_id3, Config)],
+    Mod = ?config(modname, Config),
+    meck:new(Mod, [non_strict]),
+    meck:expect(Mod, init, fun (_) -> [] end),
+    meck:expect(Mod, init_aux, fun (_) -> undefined end),
+    meck:expect(Mod, apply,
+                fun
+                    (_, Cmd, State) ->
+                        ct:pal("handling ~p", [Cmd]),
+                        %% handle all
+                        {State, ok}
+                end),
+    meck:expect(Mod, handle_aux,
+                fun
+                    (_RaftState, {call, _From}, {sleep, Sleep}, AuxState, Opaque) ->
+                        timer:sleep(Sleep),
+                        {reply, ok, AuxState, Opaque};
+                    (_RaftState, cast, _Msg, AuxState, Opaque) ->
+                        {no_reply, AuxState, Opaque}
+                end),
+    ok = start_cluster(ClusterName, {module, Mod, #{}}, Cluster),
+    ?assertEqual(ok, ra:aux_command(ServerId1, {sleep, 100}, 500)),
+    ?assertExit({timeout, _}, ra:aux_command(ServerId1, {sleep, 1000}, 500)),
+    ra:delete_cluster(Cluster),
+    ok.
+
 aux_eval(Config) ->
     %% aux handle is automatically passed an eval command after new entries
     %% have been applied