Merge pull request #11 from GameAnalytics/unnamed_scheduler

Add start_link/4 to start a scheduler without registering a name for it

Author: cmdevries

src/gascheduler.erl

@@ -6,6 +6,7 @@
 
 %% API
 -export([start_link/5,
+         start_link/4,
          stop/1,
          execute/2,
          add_worker_node/2,
@@ -80,6 +81,12 @@ start_link(Name, Nodes, Client, MaxWorkers, MaxRetries) ->
     gen_server:start_link({local, Name}, ?MODULE,
                            [Nodes, Client, MaxWorkers, MaxRetries], []).
 
+-spec start_link(worker_nodes(), client(), max_workers(), max_retries())
+          -> {ok, pid()}.
+start_link(Nodes, Client, MaxWorkers, MaxRetries) ->
+    gen_server:start_link(?MODULE,
+                           [Nodes, Client, MaxWorkers, MaxRetries], []).
+
 -spec stop(atom()) -> ok.
 stop(Name) ->
     gen_server:call(Name, stop).
@@ -196,7 +203,10 @@ handle_cast(tick, State = #state{ticks = Ticks, pending = Pending}) ->
 
 handle_cast({Result, Worker, MFA}, State = #state{running = Running,
                                                   client = Client}) ->
-    {registered_name, Name} = process_info(self(), registered_name),
+    Name = case process_info(self(), registered_name) of
+               {registered_name, N} -> N;
+               _                    -> self() %% no name, just use pid
+           end,
     Client ! {Name, Result, node(Worker), MFA},
     {noreply, State#state{running = remove_worker(Worker, Running)}};
 

test/gascheduler_test.erl

@@ -20,7 +20,8 @@ gascheduler_test_() ->
       {spawn, {timeout, 60,  ?_test(node_down())}},
       {spawn, {timeout, 60,  ?_test(unfinished())}},
       {spawn, {timeout, 60,  ?_test(permanent_failure())}},
-      {spawn, {timeout, 120, ?_test(exit_handling())}}
+      {spawn, {timeout, 120, ?_test(exit_handling())}},
+      {spawn, ?_test(unnamed_scheduler())}
     ]}.
 
 
@@ -381,6 +382,26 @@ exit_handling() ->
 
     ok.
 
+%% Start a scheduler with no name
+%% Assert no name is registered for the pid of the scheduler
+%% Execute a task through the scheduler
+%% assert that work is finished
+unnamed_scheduler() ->
+    Client = self(),
+    Nodes = [node()],
+
+    {ok, Pid} = gascheduler:start_link(Nodes, Client, 1, 1),
+
+    %% See erlang:process_info/2 on why we get a list when there is no name
+    %% registered.
+    ?assertEqual([], process_info(Pid, registered_name)),
+
+    ok = test_tasks(Pid, 1, Nodes),
+
+    ok = gascheduler:stop(Pid),
+
+    ok.
+
 
 %%
 %% Utilities
@@ -463,15 +484,18 @@ kill_if(Node) ->
     end.
 
 test_tasks(NumTasks, Nodes) ->
+    test_tasks(test, NumTasks, Nodes).
+
+test_tasks(Scheduler, NumTasks, Nodes) ->
     Tasks = lists:seq(1, NumTasks),
     ok = lists:foreach(
         fun(Id) ->
-            ok = gascheduler:execute(test, {gascheduler_test, sleep_100, [Id]})
+            ok = gascheduler:execute(Scheduler, {gascheduler_test, sleep_100, [Id]})
         end, Tasks),
     Received = lists:map(
         fun(_) ->
             receive
-                {test, {ok, Id}, Node, {Mod, Fun, Args}} ->
+                {Scheduler, {ok, Id}, Node, {Mod, Fun, Args}} ->
                     ?assertEqual(gascheduler_test, Mod),
                     ?assertEqual(sleep_100, Fun),
                     ?assertEqual(length(Args), 1),