Merge branch 'siri/sync-stop-gen/OTP-11173'

* siri/sync-stop-gen/OTP-11173:
  Add synchronous stop function to wx_object
  Fix minor bugs in gen_server and gen_fsm documentation
  Update gen_event:stop to be synchronous
  Add synchronous stop functions to gen_server and gen_fsm
  Add synchronous stop function to proc_lib
  Add system message 'terminate'
  Remove old code from stdlib/test/sys_sp2.erl

7 files changed, 319 insertions, 56 deletions

diff --git a/lib/stdlib/test/gen_event_SUITE.erl b/lib/stdlib/test/gen_event_SUITE.erl
index 60a1ba8c60..576a5adfce 100644
--- a/lib/stdlib/test/gen_event_SUITE.erl
+++ b/lib/stdlib/test/gen_event_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -106,7 +106,7 @@ start(Config) when is_list(Config) ->
     ?line {error, {already_started, _}} =
 	gen_event:start({global, my_dummy_name}),
 
-    exit(Pid6, shutdown),
+    ok = gen_event:stop({global, my_dummy_name}, shutdown, 10000),
     receive
 	{'EXIT', Pid6, shutdown} -> ok
     after 10000 ->
diff --git a/lib/stdlib/test/gen_fsm_SUITE.erl b/lib/stdlib/test/gen_fsm_SUITE.erl
index 8aeec07ae8..2e266198e9 100644
--- a/lib/stdlib/test/gen_fsm_SUITE.erl
+++ b/lib/stdlib/test/gen_fsm_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -27,6 +27,9 @@
 -export([start1/1, start2/1, start3/1, start4/1, start5/1, start6/1,
 	 start7/1, start8/1, start9/1, start10/1, start11/1, start12/1]).
 
+-export([stop1/1, stop2/1, stop3/1, stop4/1, stop5/1, stop6/1, stop7/1,
+	 stop8/1, stop9/1, stop10/1]).
+
 -export([ abnormal1/1, abnormal2/1]).
 
 -export([shutdown/1]).
@@ -64,6 +67,8 @@ groups() ->
     [{start, [],
       [start1, start2, start3, start4, start5, start6, start7,
        start8, start9, start10, start11, start12]},
+     {stop, [],
+      [stop1, stop2, stop3, stop4, stop5, stop6, stop7, stop8, stop9, stop10]},
      {abnormal, [], [abnormal1, abnormal2]},
      {sys, [],
       [sys1, call_format_status, error_format_status, get_state, replace_state]}].
@@ -278,6 +283,105 @@ start12(Config) when is_list(Config) ->
     ok.
 
 
+%% Anonymous, reason 'normal'
+stop1(_Config) ->
+    {ok, Pid} = gen_fsm:start(?MODULE, [], []),
+    ok = gen_fsm:stop(Pid),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_fsm:stop(Pid)),
+    ok.
+
+%% Anonymous, other reason
+stop2(_Config) ->
+    {ok,Pid} = gen_fsm:start(?MODULE, [], []),
+    ok = gen_fsm:stop(Pid, other_reason, infinity),
+    false = erlang:is_process_alive(Pid),
+    ok.
+
+%% Anonymous, invalid timeout
+stop3(_Config) ->
+    {ok,Pid} = gen_fsm:start(?MODULE, [], []),
+    {'EXIT',_} = (catch gen_fsm:stop(Pid, other_reason, invalid_timeout)),
+    true = erlang:is_process_alive(Pid),
+    ok = gen_fsm:stop(Pid),
+    false = erlang:is_process_alive(Pid),
+    ok.
+
+%% Registered name
+stop4(_Config) ->
+    {ok,Pid} = gen_fsm:start({local,to_stop},?MODULE, [], []),
+    ok = gen_fsm:stop(to_stop),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_fsm:stop(to_stop)),
+    ok.
+
+%% Registered name and local node
+stop5(_Config) ->
+    {ok,Pid} = gen_fsm:start({local,to_stop},?MODULE, [], []),
+    ok = gen_fsm:stop({to_stop,node()}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_fsm:stop({to_stop,node()})),
+    ok.
+
+%% Globally registered name
+stop6(_Config) ->
+    {ok, Pid} = gen_fsm:start({global, to_stop}, ?MODULE, [], []),
+    ok = gen_fsm:stop({global,to_stop}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_fsm:stop({global,to_stop})),
+    ok.
+
+%% 'via' registered name
+stop7(_Config) ->
+    dummy_via:reset(),
+    {ok, Pid} = gen_fsm:start({via, dummy_via, to_stop},
+				  ?MODULE, [], []),
+    ok = gen_fsm:stop({via, dummy_via, to_stop}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_fsm:stop({via, dummy_via, to_stop})),
+    ok.
+
+%% Anonymous on remote node
+stop8(_Config) ->
+    {ok,Node} = test_server:start_node(gen_fsm_SUITE_stop8,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_fsm,start,[?MODULE,[],[]]),
+    ok = gen_fsm:stop(Pid),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_fsm:stop(Pid)),
+    true = test_server:stop_node(Node),
+    {'EXIT',{{nodedown,Node},_}} = (catch gen_fsm:stop(Pid)),
+    ok.
+
+%% Registered name on remote node
+stop9(_Config) ->
+    {ok,Node} = test_server:start_node(gen_fsm_SUITE_stop9,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_fsm,start,[{local,to_stop},?MODULE,[],[]]),
+    ok = gen_fsm:stop({to_stop,Node}),
+    undefined = rpc:call(Node,erlang,whereis,[to_stop]),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_fsm:stop({to_stop,Node})),
+    true = test_server:stop_node(Node),
+    {'EXIT',{{nodedown,Node},_}} = (catch gen_fsm:stop({to_stop,Node})),
+    ok.
+
+%% Globally registered name on remote node
+stop10(_Config) ->
+    {ok,Node} = test_server:start_node(gen_fsm_SUITE_stop10,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_fsm,start,[{global,to_stop},?MODULE,[],[]]),
+    global:sync(),
+    ok = gen_fsm:stop({global,to_stop}),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_fsm:stop({global,to_stop})),
+    true = test_server:stop_node(Node),
+    {'EXIT',noproc} = (catch gen_fsm:stop({global,to_stop})),
+    ok.
+
 %% Check that time outs in calls work
 abnormal1(suite) -> [];
 abnormal1(Config) when is_list(Config) ->
diff --git a/lib/stdlib/test/gen_server_SUITE.erl b/lib/stdlib/test/gen_server_SUITE.erl
index 960e7f60e7..c3ec4932b3 100644
--- a/lib/stdlib/test/gen_server_SUITE.erl
+++ b/lib/stdlib/test/gen_server_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -35,6 +35,9 @@
 	 error_format_status/1, get_state/1, replace_state/1, call_with_huge_message_queue/1
 	]).
 
+-export([stop1/1, stop2/1, stop3/1, stop4/1, stop5/1, stop6/1, stop7/1,
+	 stop8/1, stop9/1, stop10/1]).
+
 % spawn export
 -export([spec_init_local/2, spec_init_global/2, spec_init_via/2,
 	 spec_init_default_timeout/2, spec_init_global_default_timeout/2,
@@ -50,7 +53,7 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [start, crash, call, cast, cast_fast, info, abcast,
+    [start, {group,stop}, crash, call, cast, cast_fast, info, abcast,
      multicall, multicall_down, call_remote1, call_remote2,
      call_remote3, call_remote_n1, call_remote_n2,
      call_remote_n3, spec_init,
@@ -61,7 +64,8 @@ all() ->
      call_with_huge_message_queue].
 
 groups() -> 
-    [].
+    [{stop, [],
+      [stop1, stop2, stop3, stop4, stop5, stop6, stop7, stop8, stop9, stop10]}].
 
 init_per_suite(Config) ->
     Config.
@@ -235,6 +239,105 @@ start(Config) when is_list(Config) ->
     process_flag(trap_exit, OldFl),
     ok.
 
+%% Anonymous, reason 'normal'
+stop1(_Config) ->
+    {ok, Pid} = gen_server:start(?MODULE, [], []),
+    ok = gen_server:stop(Pid),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_server:stop(Pid)),
+    ok.
+
+%% Anonymous, other reason
+stop2(_Config) ->
+    {ok,Pid} = gen_server:start(?MODULE, [], []),
+    ok = gen_server:stop(Pid, other_reason, infinity),
+    false = erlang:is_process_alive(Pid),
+    ok.
+
+%% Anonymous, invalid timeout
+stop3(_Config) ->
+    {ok,Pid} = gen_server:start(?MODULE, [], []),
+    {'EXIT',_} = (catch gen_server:stop(Pid, other_reason, invalid_timeout)),
+    true = erlang:is_process_alive(Pid),
+    ok = gen_server:stop(Pid),
+    false = erlang:is_process_alive(Pid),
+    ok.
+
+%% Registered name
+stop4(_Config) ->
+    {ok,Pid} = gen_server:start({local,to_stop},?MODULE, [], []),
+    ok = gen_server:stop(to_stop),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_server:stop(to_stop)),
+    ok.
+
+%% Registered name and local node
+stop5(_Config) ->
+    {ok,Pid} = gen_server:start({local,to_stop},?MODULE, [], []),
+    ok = gen_server:stop({to_stop,node()}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_server:stop({to_stop,node()})),
+    ok.
+
+%% Globally registered name
+stop6(_Config) ->
+    {ok, Pid} = gen_server:start({global, to_stop}, ?MODULE, [], []),
+    ok = gen_server:stop({global,to_stop}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_server:stop({global,to_stop})),
+    ok.
+
+%% 'via' registered name
+stop7(_Config) ->
+    dummy_via:reset(),
+    {ok, Pid} = gen_server:start({via, dummy_via, to_stop},
+				  ?MODULE, [], []),
+    ok = gen_server:stop({via, dummy_via, to_stop}),
+    false = erlang:is_process_alive(Pid),
+    {'EXIT',noproc} = (catch gen_server:stop({via, dummy_via, to_stop})),
+    ok.
+
+%% Anonymous on remote node
+stop8(_Config) ->
+    {ok,Node} = test_server:start_node(gen_server_SUITE_stop8,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_server,start,[?MODULE,[],[]]),
+    ok = gen_server:stop(Pid),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_server:stop(Pid)),
+    true = test_server:stop_node(Node),
+    {'EXIT',{{nodedown,Node},_}} = (catch gen_server:stop(Pid)),
+    ok.
+
+%% Registered name on remote node
+stop9(_Config) ->
+    {ok,Node} = test_server:start_node(gen_server_SUITE_stop9,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_server,start,[{local,to_stop},?MODULE,[],[]]),
+    ok = gen_server:stop({to_stop,Node}),
+    undefined = rpc:call(Node,erlang,whereis,[to_stop]),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_server:stop({to_stop,Node})),
+    true = test_server:stop_node(Node),
+    {'EXIT',{{nodedown,Node},_}} = (catch gen_server:stop({to_stop,Node})),
+    ok.
+
+%% Globally registered name on remote node
+stop10(_Config) ->
+    {ok,Node} = test_server:start_node(gen_server_SUITE_stop10,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    {ok, Pid} = rpc:call(Node,gen_server,start,[{global,to_stop},?MODULE,[],[]]),
+    global:sync(),
+    ok = gen_server:stop({global,to_stop}),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid]),
+    {'EXIT',noproc} = (catch gen_server:stop({global,to_stop})),
+    true = test_server:stop_node(Node),
+    {'EXIT',noproc} = (catch gen_server:stop({global,to_stop})),
+    ok.
+
 crash(Config) when is_list(Config) ->
     ?line error_logger_forwarder:register(),
 
diff --git a/lib/stdlib/test/proc_lib_SUITE.erl b/lib/stdlib/test/proc_lib_SUITE.erl
index 8dca69bac4..b6f1973a05 100644
--- a/lib/stdlib/test/proc_lib_SUITE.erl
+++ b/lib/stdlib/test/proc_lib_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -27,7 +27,7 @@
 	 init_per_group/2,end_per_group/2, 
 	 crash/1, sync_start_nolink/1, sync_start_link/1,
          spawn_opt/1, sp1/0, sp2/0, sp3/1, sp4/2, sp5/1,
-	 hibernate/1]).
+	 hibernate/1, stop/1]).
 -export([ otp_6345/1, init_dont_hang/1]).
 
 -export([hib_loop/1, awaken/1]).
@@ -38,6 +38,7 @@
 
 -export([otp_6345_init/1, init_dont_hang_init/1]).
 
+-export([system_terminate/4]).
 
 -ifdef(STANDALONE).
 -define(line, noop, ).
@@ -49,7 +50,7 @@ suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
     [crash, {group, sync_start}, spawn_opt, hibernate,
-     {group, tickets}].
+     {group, tickets}, stop].
 
 groups() -> 
     [{tickets, [], [otp_6345, init_dont_hang]},
@@ -361,10 +362,94 @@ init_dont_hang(Config) when is_list(Config) ->
 	    exit(Error)
     end.
 
-init_dont_hang_init(Parent) ->
+init_dont_hang_init(_Parent) ->
     1 = 2.
 
+%% Test proc_lib:stop/1,3
+stop(_Config) ->
+    Parent = self(),
+    SysMsgProc =
+	fun() ->
+		receive
+		    {system,From,Request} ->
+			sys:handle_system_msg(Request,From,Parent,?MODULE,[],[])
+		end
+	end,
+
+    %% Normal case:
+    %% Process handles system message and terminated with given reason
+    Pid1 = proc_lib:spawn(SysMsgProc),
+    ok = proc_lib:stop(Pid1),
+    false = erlang:is_process_alive(Pid1),
+
+    %% Process does not exit
+    {'EXIT',noproc} = (catch proc_lib:stop(Pid1)),
+
+    %% Badly handled system message
+    DieProc =
+	fun() ->
+		receive
+		    {system,_From,_Request} ->
+			exit(die)
+		end
+	end,
+    Pid2 = proc_lib:spawn(DieProc),
+    {'EXIT',{die,_}} = (catch proc_lib:stop(Pid2)),
+
+    %% Hanging process => timeout
+    HangProc =
+	fun() ->
+		receive
+		    {system,_From,_Request} ->
+			timer:sleep(5000)
+		end
+	end,
+    Pid3 = proc_lib:spawn(HangProc),
+    {'EXIT',timeout} = (catch proc_lib:stop(Pid3,normal,1000)),
+
+    %% Success case with other reason than 'normal'
+    Pid4 = proc_lib:spawn(SysMsgProc),
+    ok = proc_lib:stop(Pid4,other_reason,infinity),
+    false = erlang:is_process_alive(Pid4),
+
+    %% System message is handled, but process dies with other reason
+    %% than the given (in system_terminate/4 below)
+    Pid5 = proc_lib:spawn(SysMsgProc),
+    {'EXIT',{badmatch,2}} = (catch proc_lib:stop(Pid5,crash,infinity)),
+    false = erlang:is_process_alive(Pid5),
+
+    %% Local registered name
+    Pid6 = proc_lib:spawn(SysMsgProc),
+    register(to_stop,Pid6),
+    ok = proc_lib:stop(to_stop),
+    undefined = whereis(to_stop),
+    false = erlang:is_process_alive(Pid6),
+
+    %% Remote registered name
+    {ok,Node} = test_server:start_node(proc_lib_SUITE_stop,slave,[]),
+    Dir = filename:dirname(code:which(?MODULE)),
+    rpc:call(Node,code,add_path,[Dir]),
+    Pid7 = spawn(Node,SysMsgProc),
+    true = rpc:call(Node,erlang,register,[to_stop,Pid7]),
+    Pid7 = rpc:call(Node,erlang,whereis,[to_stop]),
+    ok = proc_lib:stop({to_stop,Node}),
+    undefined = rpc:call(Node,erlang,whereis,[to_stop]),
+    false = rpc:call(Node,erlang,is_process_alive,[Pid7]),
+
+    %% Local and remote registered name, but non-existing
+    {'EXIT',noproc} = (catch proc_lib:stop(to_stop)),
+    {'EXIT',noproc} = (catch proc_lib:stop({to_stop,Node})),
+
+    true = test_server:stop_node(Node),
+    
+    %% Remote registered name, but non-existing node
+    {'EXIT',{{nodedown,Node},_}} = (catch proc_lib:stop({to_stop,Node})),
+    ok.
 
+system_terminate(crash,_Parent,_Deb,_State) ->
+    1 = 2;
+system_terminate(Reason,_Parent,_Deb,_State) ->
+    exit(Reason).
 
 %%-----------------------------------------------------------------
 %% The error_logger handler used.
diff --git a/lib/stdlib/test/sys_SUITE.erl b/lib/stdlib/test/sys_SUITE.erl
index f38bc87ae5..047ee9f1fa 100644
--- a/lib/stdlib/test/sys_SUITE.erl
+++ b/lib/stdlib/test/sys_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -202,14 +202,7 @@ spec_proc(Mod) ->
 		       {Mod,system_get_state},{throw,fail}},_}} ->
 		 ok
 	 end,
-    Mod:stop(),
-    WaitForUnregister = fun W() ->
-		       case whereis(Mod) of
-			   undefined -> ok;
-			   _ -> timer:sleep(10), W()
-		       end
-	       end,
-    WaitForUnregister(),
+    ok = sys:terminate(Mod, normal),
     {ok,_} = Mod:start_link(4),
     ok = case catch sys:replace_state(Mod, fun(_) -> {} end) of
 	     {} ->
@@ -218,8 +211,7 @@ spec_proc(Mod) ->
 		       {Mod,system_replace_state},{throw,fail}},_}} ->
 		 ok
 	 end,
-    Mod:stop(),
-    WaitForUnregister(),
+    ok = sys:terminate(Mod, normal),
     {ok,_} = Mod:start_link(4),
     StateFun = fun(_) -> error(fail) end,
     ok = case catch sys:replace_state(Mod, StateFun) of
@@ -231,7 +223,7 @@ spec_proc(Mod) ->
 	     {'EXIT',{{callback_failed,StateFun,{error,fail}},_}} ->
 		 ok
 	 end,
-    Mod:stop().
+    ok = sys:terminate(Mod, normal).
 
 %%%%%%%%%%%%%%%%%%%%
 %% Dummy server
diff --git a/lib/stdlib/test/sys_sp1.erl b/lib/stdlib/test/sys_sp1.erl
index e84ffcfa12..0fb288991f 100644
--- a/lib/stdlib/test/sys_sp1.erl
+++ b/lib/stdlib/test/sys_sp1.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -17,7 +17,7 @@
 %% %CopyrightEnd%
 %%
 -module(sys_sp1).
--export([start_link/1, stop/0]).
+-export([start_link/1]).
 -export([alloc/0, free/1]).
 -export([init/1]).
 -export([system_continue/3, system_terminate/4,
@@ -31,10 +31,6 @@
 start_link(NumCh) ->
     proc_lib:start_link(?MODULE, init, [[self(),NumCh]]).
 
-stop() ->
-    ?MODULE ! stop,
-    ok.
-
 alloc() ->
     ?MODULE ! {self(), alloc},
     receive
@@ -70,11 +66,7 @@ loop(Chs, Parent, Deb) ->
             loop(Chs2, Parent, Deb2);
         {system, From, Request} ->
             sys:handle_system_msg(Request, From, Parent,
-                                  ?MODULE, Deb, Chs);
-        stop ->
-            sys:handle_debug(Deb, fun write_debug/3,
-                             ?MODULE, {in, stop}),
-            ok
+                                  ?MODULE, Deb, Chs)
     end.
 
 system_continue(Parent, Deb, Chs) ->
diff --git a/lib/stdlib/test/sys_sp2.erl b/lib/stdlib/test/sys_sp2.erl
index 56a5e4d071..a0847b5838 100644
--- a/lib/stdlib/test/sys_sp2.erl
+++ b/lib/stdlib/test/sys_sp2.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -17,7 +17,7 @@
 %% %CopyrightEnd%
 %%
 -module(sys_sp2).
--export([start_link/1, stop/0]).
+-export([start_link/1]).
 -export([alloc/0, free/1]).
 -export([init/1]).
 -export([system_continue/3, system_terminate/4,
@@ -30,10 +30,6 @@
 start_link(NumCh) ->
     proc_lib:start_link(?MODULE, init, [[self(),NumCh]]).
 
-stop() ->
-    ?MODULE ! stop,
-    ok.
-
 alloc() ->
     ?MODULE ! {self(), alloc},
     receive
@@ -45,11 +41,6 @@ free(Ch) ->
     ?MODULE ! {free, Ch},
     ok.
 
-%% can't use 2-tuple for state here as we do in sys_sp1, since the 2-tuple
-%% is not compatible with the backward compatibility handling for
-%% sys:get_state in sys.erl
--record(state, {alloc,free}).
-
 init([Parent,NumCh]) ->
     register(?MODULE, self()),
     Chs = channels(NumCh),
@@ -74,11 +65,7 @@ loop(Chs, Parent, Deb) ->
             loop(Chs2, Parent, Deb2);
         {system, From, Request} ->
             sys:handle_system_msg(Request, From, Parent,
-                                  ?MODULE, Deb, Chs);
-        stop ->
-            sys:handle_debug(Deb, fun write_debug/3,
-                             ?MODULE, {in, stop}),
-            ok
+                                  ?MODULE, Deb, Chs)
     end.
 
 system_continue(Parent, Deb, Chs) ->
@@ -91,17 +78,17 @@ write_debug(Dev, Event, Name) ->
     io:format(Dev, "~p event = ~p~n", [Name, Event]).
 
 channels(NumCh) ->
-    #state{alloc=[], free=lists:seq(1,NumCh)}.
+    {_Allocated=[], _Free=lists:seq(1,NumCh)}.
 
-alloc(#state{free=[]}=Channels) ->
-    {{error, "no channels available"}, Channels};
-alloc(#state{alloc=Allocated, free=[H|T]}) ->
-    {H, #state{alloc=[H|Allocated], free=T}}.
+alloc({_, []}) ->
+    {error, "no channels available"};
+alloc({Allocated, [H|T]}) ->
+    {H, {[H|Allocated], T}}.
 
-free(Ch, #state{alloc=Alloc, free=Free}=Channels) ->
+free(Ch, {Alloc, Free}=Channels) ->
     case lists:member(Ch, Alloc) of
         true ->
-            #state{alloc=lists:delete(Ch, Alloc), free=[Ch|Free]};
+            {lists:delete(Ch, Alloc), [Ch|Free]};
         false ->
             Channels
     end.