1 files changed, 83 insertions, 0 deletions
diff --git a/lib/common_test/src/ct_default_gl.erl b/lib/common_test/src/ct_default_gl.erl
new file mode 100644
index 0000000000..d1b52e5f4f
--- /dev/null
+++ b/lib/common_test/src/ct_default_gl.erl
@@ -0,0 +1,83 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2012-2016. All Rights Reserved.
+%%
+%% Licensed 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.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(ct_default_gl).
+-export([start_link/1, stop/0]).
+
+-export([init/1,handle_call/3,handle_cast/2,handle_info/2,terminate/2]).
+
+%% start_link()
+%% Start a new group leader process.
+start_link(ParentGL) ->
+    do_start(ParentGL, 3).
+
+do_start(_ParentGL, 0) ->
+    exit({?MODULE,startup});
+do_start(ParentGL, Retries) ->
+    case whereis(?MODULE) of
+	undefined ->
+	    case gen_server:start_link(?MODULE, [ParentGL], []) of
+		{ok,Pid} ->
+		    {ok,Pid};
+		Other ->
+		    Other
+	    end;
+	Pid ->
+	    exit(Pid, kill),
+	    timer:sleep(1000),
+	    do_start(ParentGL, Retries-1)
+    end.
+
+%% stop(Pid)
+%% Stop a group leader process.
+stop() ->
+    gen_server:cast(whereis(?MODULE), stop).
+
+
+%%% Internal functions.
+
+init([ParentGL]) ->
+    register(?MODULE, self()),
+    {ok,#{parent_gl_pid => ParentGL,
+	  parent_gl_monitor => erlang:monitor(process,ParentGL)}}.
+
+handle_cast(stop, St) ->
+    {stop,normal,St}.
+
+%% If the parent group leader dies, fall back on using the local user process
+handle_info({'DOWN',Ref,process,_,_Reason}, #{parent_gl_monitor := Ref} = St) ->
+    User = whereis(user),
+    {noreply,St#{parent_gl_pid => User,
+		 parent_gl_monitor => erlang:monitor(process,User)}};
+
+handle_info({io_request,_From,_ReplyAs,_Req} = IoReq,
+	    #{parent_gl_pid := ParentGL} = St) ->
+    ParentGL ! IoReq,
+    {noreply,St};
+
+handle_info(Msg, St) ->
+    io:format(user, "Common Test Group Leader process got: ~tp~n", [Msg]),
+    {noreply,St}.
+
+handle_call(_Req, _From, St) ->
+    {reply,ok,St}.
+
+terminate(_, _) ->
+    ok.