Add documentation and test for kernel env var shutdown_timeout

2 files changed, 77 insertions, 0 deletions

diff --git a/lib/kernel/test/application_SUITE_data/deadlock/deadlock.app b/lib/kernel/test/application_SUITE_data/deadlock/deadlock.app
new file mode 100644
index 0000000000..0c1001bed6
--- /dev/null
+++ b/lib/kernel/test/application_SUITE_data/deadlock/deadlock.app
@@ -0,0 +1,8 @@
+{application, deadlock, [
+  {vsn, "1"},
+  {registered, []},
+  {applications, [kernel, stdlib, sasl]},
+  {modules, [deadlock]},
+  {mod, {deadlock, []}},
+  {env, [{fail_start, false}]}
+]}.
diff --git a/lib/kernel/test/application_SUITE_data/deadlock/deadlock.erl b/lib/kernel/test/application_SUITE_data/deadlock/deadlock.erl
new file mode 100644
index 0000000000..5f68bf9078
--- /dev/null
+++ b/lib/kernel/test/application_SUITE_data/deadlock/deadlock.erl
@@ -0,0 +1,69 @@
+-module(deadlock).
+-behaviour(application).
+-compile(export_all).
+-define(SUP,deadlock_sup).
+-define(CHILD,deadlock_child).
+
+
+%%%-----------------------------------------------------------------
+%%% application callbacks
+start(_StartType, _StartArgs) ->
+    supervisor:start_link({local, ?SUP}, ?MODULE, [sup]).
+
+stop(_State) ->
+    ok.
+
+
+
+%%%-----------------------------------------------------------------
+%%% supervisor callbacks
+init([sup]) ->
+    {ok, {{one_for_one, 5, 10}, [
+        {
+            sasl_syslog_dm, {?MODULE, start_link, []},
+            permanent, brutal_kill, worker,
+            [deadlock]
+        }
+    ]}};
+
+
+%%%-----------------------------------------------------------------
+%%% gen_server callbacks
+init([child]) ->
+    case application:get_env(deadlock, fail_start) of
+        {ok, false} ->
+            %% we must not fail on the first init, otherwise supervisor
+            %% terminates immediately
+            {ok, []};
+        {ok, true}  ->
+	    timer:sleep(infinity), % init hangs!!!!
+	    {ok, []}
+    end.
+
+handle_call(_Req, _From, State) ->
+    {reply, ok, State}.
+
+handle_cast(restart, State) ->
+    {stop, error, State}.
+
+handle_info(_Msg, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+
+%%%-----------------------------------------------------------------
+%%% Start child
+start_link() ->
+    gen_server:start_link({local, ?CHILD}, ?MODULE, [child], []).
+
+
+%%%-----------------------------------------------------------------
+%%% Provoke hanging
+restart_and_fail() ->
+    application:set_env(deadlock, fail_start, true), % next init will hang
+    gen_server:cast(?CHILD, restart).