4 files changed, 68 insertions, 0 deletions
diff --git a/lib/stdlib/src/gen_event.erl b/lib/stdlib/src/gen_event.erl
index 2b8ba86909..bfebf29080 100644
--- a/lib/stdlib/src/gen_event.erl
+++ b/lib/stdlib/src/gen_event.erl
@@ -229,6 +229,24 @@ wake_hib(Parent, ServerName, MSL, Debug) ->
 
 fetch_msg(Parent, ServerName, MSL, Debug, Hib) ->
     receive
+	{system, From, get_state} ->
+	    States = [{Mod,Id,State} || #handler{module=Mod, id=Id, state=State} <- MSL],
+	    sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
+				  {States, [ServerName, MSL, Hib]}, Hib);
+	{system, From, {replace_state, StateFun}} ->
+	    {NMSL, NStates} =
+		lists:unzip([begin
+				 Cur = {Mod,Id,State},
+				 try
+				     NState = {Mod,Id,NS} = StateFun(Cur),
+				     {HS#handler{state=NS}, NState}
+				 catch
+				     _:_ ->
+					 {HS, Cur}
+				 end
+			     end || #handler{module=Mod, id=Id, state=State}=HS <- MSL]),
+	    sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
+				  {NStates, [ServerName, NMSL, Hib]}, Hib);
 	{system, From, Req} ->
 	    sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
 				  [ServerName, MSL, Hib],Hib);
diff --git a/lib/stdlib/src/gen_fsm.erl b/lib/stdlib/src/gen_fsm.erl
index e480e2ac11..d9411e58cf 100644
--- a/lib/stdlib/src/gen_fsm.erl
+++ b/lib/stdlib/src/gen_fsm.erl
@@ -422,6 +422,17 @@ wake_hib(Parent, Name, StateName, StateData, Mod, Debug) ->
 
 decode_msg(Msg,Parent, Name, StateName, StateData, Mod, Time, Debug, Hib) ->
     case Msg of
+	{system, From, get_state} ->
+	    Misc = [Name, StateName, StateData, Mod, Time],
+	    sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
+				  {{StateName, StateData}, Misc}, Hib);
+	{system, From, {replace_state, StateFun}} ->
+	    State = {StateName, StateData},
+	    NState = {NStateName, NStateData} = try StateFun(State)
+						catch _:_ -> State end,
+	    NMisc = [Name, NStateName, NStateData, Mod, Time],
+	    sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
+				  {NState, NMisc}, Hib);
         {system, From, Req} ->
 	    sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
 				  [Name, StateName, StateData, Mod, Time], Hib);
diff --git a/lib/stdlib/src/gen_server.erl b/lib/stdlib/src/gen_server.erl
index 04308a51b7..9c4b95acf6 100644
--- a/lib/stdlib/src/gen_server.erl
+++ b/lib/stdlib/src/gen_server.erl
@@ -372,6 +372,13 @@ wake_hib(Parent, Name, State, Mod, Debug) ->
 
 decode_msg(Msg, Parent, Name, State, Mod, Time, Debug, Hib) ->
     case Msg of
+	{system, From, get_state} ->
+	    sys:handle_system_msg(get_state, From, Parent, ?MODULE, Debug,
+				  {State, [Name, State, Mod, Time]}, Hib);
+	{system, From, {replace_state, StateFun}} ->
+	    NState = try StateFun(State) catch _:_ -> State end,
+	    sys:handle_system_msg(replace_state, From, Parent, ?MODULE, Debug,
+				  {NState, [Name, NState, Mod, Time]}, Hib);
 	{system, From, Req} ->
 	    sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
 				  [Name, State, Mod, Time], Hib);
diff --git a/lib/stdlib/src/sys.erl b/lib/stdlib/src/sys.erl
index 2d6287814e..bffeb44179 100644
--- a/lib/stdlib/src/sys.erl
+++ b/lib/stdlib/src/sys.erl
@@ -21,6 +21,8 @@
 %% External exports
 -export([suspend/1, suspend/2, resume/1, resume/2,
 	 get_status/1, get_status/2,
+	 get_state/1, get_state/2,
+	 replace_state/2, replace_state/3,
 	 change_code/4, change_code/5,
 	 log/2, log/3, trace/2, trace/3, statistics/2, statistics/3,
 	 log_to_file/2, log_to_file/3, no_debug/1, no_debug/2,
@@ -97,6 +99,32 @@ get_status(Name) -> send_system_msg(Name, get_status).
              | (Misc :: term()).
 get_status(Name, Timeout) -> send_system_msg(Name, get_status, Timeout).
 
+-spec get_state(Name) -> State when
+      Name :: name(),
+      State :: term().
+get_state(Name) -> send_system_msg(Name, get_state).
+
+-spec get_state(Name, Timeout) -> State when
+      Name :: name(),
+      Timeout :: timeout(),
+      State :: term().
+get_state(Name, Timeout) -> send_system_msg(Name, get_state, Timeout).
+
+-spec replace_state(Name, StateFun) -> NewState when
+      Name :: name(),
+      StateFun :: fun((State :: term()) -> NewState :: term()),
+      NewState :: term().
+replace_state(Name, StateFun) ->
+    send_system_msg(Name, {replace_state, StateFun}).
+
+-spec replace_state(Name, StateFun, Timeout) -> NewState when
+      Name :: name(),
+      StateFun :: fun((State :: term()) -> NewState :: term()),
+      Timeout :: timeout(),
+      NewState :: term().
+replace_state(Name, StateFun, Timeout) ->
+    send_system_msg(Name, {replace_state, StateFun}, Timeout).
+
 -spec change_code(Name, Module, OldVsn, Extra) -> 'ok' | {error, Reason} when
       Name :: name(),
       Module :: module(),
@@ -362,6 +390,10 @@ do_cmd(_, suspend, _Parent, _Mod, Debug, Misc) ->
     {suspended, ok, Debug, Misc};
 do_cmd(_, resume, _Parent, _Mod, Debug, Misc) ->
     {running, ok, Debug, Misc};
+do_cmd(SysState, get_state, _Parent, _Mod, Debug, {State, Misc}) ->
+    {SysState, State, Debug, Misc};
+do_cmd(SysState, replace_state, _Parent, _Mod, Debug, {State, Misc}) ->
+    {SysState, State, Debug, Misc};
 do_cmd(SysState, get_status, Parent, Mod, Debug, Misc) ->
     Res = get_status(SysState, Parent, Mod, Debug, Misc),
     {SysState, Res, Debug, Misc};