The R13B03 release.OTP_R13B03

1 files changed, 943 insertions, 0 deletions

diff --git a/erts/emulator/test/monitor_SUITE.erl b/erts/emulator/test/monitor_SUITE.erl
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+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 1999-2009. 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
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(monitor_SUITE).
+
+-include("test_server.hrl").
+
+-export([all/1,
+	 case_1/1, case_1a/1, case_2/1, case_2a/1, mon_e_1/1, demon_e_1/1, demon_1/1,
+	 demon_2/1, demon_3/1, demonitor_flush/1, remove_monitor/1,
+	 local_remove_monitor/1, remote_remove_monitor/1, mon_1/1, mon_2/1,
+	 large_exit/1, list_cleanup/1, mixer/1, named_down/1, otp_5827/1]).
+
+-export([init_per_testcase/2, fin_per_testcase/2]).
+
+-export([y2/1, g/1, g0/0, g1/0, large_exit_sub/1]).
+
+all(suite) ->
+    [case_1, case_1a, case_2, case_2a, mon_e_1, demon_e_1, demon_1, mon_1,
+     mon_2, demon_2, demon_3, demonitor_flush, remove_monitor,
+     large_exit, list_cleanup, mixer, named_down,
+     otp_5827].
+
+init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
+    Dog=?t:timetrap(?t:minutes(15)),
+    [{watchdog, Dog}|Config].
+
+fin_per_testcase(_Func, Config) ->
+    Dog=?config(watchdog, Config),
+    ?t:timetrap_cancel(Dog).
+
+case_1(doc) ->
+    "A monitors B, B kills A and then exits (yielded core dump)";
+case_1(suite) -> [];
+case_1(Config) when is_list(Config) ->
+    ?line process_flag(trap_exit, true),
+    ?line spawn_link(?MODULE, g0, []),
+    ?line receive _ -> ok end,
+    ok.
+
+case_1a(doc) ->
+    "A monitors B, B kills A and then exits (yielded core dump)";
+case_1a(Config) when is_list(Config) ->
+    ?line process_flag(trap_exit, true),
+    ?line spawn_link(?MODULE, g1, []),
+    ?line receive _ -> ok end,
+    ok.
+
+g0() ->
+    ?line B = spawn(?MODULE, g, [self()]),
+    ?line erlang:monitor(process, B),
+    ?line B ! ok,
+    ?line receive ok -> ok end,
+    ok.
+
+g1() ->
+    ?line {B,_} = spawn_monitor(?MODULE, g, [self()]),
+    ?line B ! ok,
+    ?line receive ok -> ok end,
+    ok.
+
+g(Parent) ->
+    ?line receive ok -> ok end,
+    ?line exit(Parent, foo),
+    ?line ok.
+
+
+case_2(doc) ->
+    "A monitors B, B demonitors A (yielded core dump)";
+case_2(Config) when is_list(Config) ->
+    ?line B = spawn(?MODULE, y2, [self()]),
+    ?line R = erlang:monitor(process, B),
+    ?line B ! R,
+    ?line receive
+	      {'EXIT', _} -> ok;
+	      Other ->
+		  test_server:fail({rec, Other})
+	  end,
+    ?line expect_down(R, B, normal),
+    ok.
+
+case_2a(doc) ->
+    "A monitors B, B demonitors A (yielded core dump)";
+case_2a(Config) when is_list(Config) ->
+    ?line {B,R} = spawn_monitor(?MODULE, y2, [self()]),
+    ?line B ! R,
+    ?line receive
+	      {'EXIT', _} -> ok;
+	      Other ->
+		  test_server:fail({rec, Other})
+	  end,
+    ?line expect_down(R, B, normal),
+    ok.
+
+y2(Parent) ->
+    ?line R = receive T -> T end,
+    ?line Parent ! (catch erlang:demonitor(R)),
+    ok.
+
+expect_down(Ref, P) ->
+    receive
+	{'DOWN', Ref, process, P, Reason} -> 
+	    Reason;
+	Other ->
+	    test_server:fail({rec, Other})
+    end.
+
+expect_down(Ref, P, Reason) ->
+    receive
+	{'DOWN', Ref, process, P, Reason} -> 
+	    ok;
+	Other ->
+	    test_server:fail({rec, Other})
+    end.
+
+expect_no_msg() ->
+    receive
+	Msg ->
+	    test_server:fail({msg, Msg})
+    after 0 ->
+	    ok
+    end.
+
+%%% Error cases for monitor/2
+
+mon_e_1(doc) ->
+    "Error cases for monitor/2";
+mon_e_1(suite) -> [];
+mon_e_1(Config) when is_list(Config) ->
+    ?line {ok, N} = test_server:start_node(hej, slave, []),
+    ?line mon_error(plutt, self()),
+    ?line mon_error(process, [bingo]),
+    ?line mon_error(process, {rex, N, junk}),
+    ?line mon_error(process, 1),
+
+    ?line true = test_server:stop_node(N),
+    ok.
+
+%%% We would also like to have a test case that tries to monitor something
+%%% on an R5 node, but this isn't possible to do systematically.
+%%%
+%%% Likewise against an R6 node, which is not capable of monitoring
+%%% by name, which gives a badarg on the R7 node at the call to
+%%% erlang:monitor(process, {Name, Node}). This has been tested 
+%%% manually at least once.
+
+mon_error(Type, Item) ->
+    case catch erlang:monitor(Type, Item) of
+	{'EXIT', _} ->
+	    ok;
+	Other ->
+	    test_server:fail({err, Other})
+    end.
+
+%%% Error cases for demonitor/1
+
+demon_e_1(doc) ->
+    "Error cases for demonitor/1";
+demon_e_1(suite) -> [];
+demon_e_1(Config) when is_list(Config) ->
+    ?line {ok, N} = test_server:start_node(hej, slave, []),
+    ?line demon_error(plutt, badarg),
+    ?line demon_error(1, badarg),
+
+    %% Demonitor with ref created at other node
+    ?line R1 = rpc:call(N, erlang, make_ref, []),
+    ?line demon_error(R1, badarg),
+
+    %% Demonitor with ref created at wrong monitor link end
+    ?line P0 = self(),
+    ?line P2 = spawn(
+		 fun() ->
+			 P0 ! {self(), ref, erlang:monitor(process,P0)},
+			 receive {P0, stop} -> ok end
+		 end ),
+    ?line receive 
+	      {P2, ref, R2} -> 
+		  ?line demon_error(R2, badarg),
+		  ?line P2 ! {self(), stop};
+	      Other2 ->
+		  test_server:fail({rec, Other2})
+	  end,
+
+    ?line true = test_server:stop_node(N),
+    ok.
+
+demon_error(Ref, Reason) ->
+    case catch erlang:demonitor(Ref) of
+	{'EXIT', {Reason, _}} ->
+	    ok;
+	Other ->
+	    test_server:fail({err, Other})
+    end.
+
+%%% No-op cases for demonitor/1
+
+demon_1(doc) ->
+    "demonitor/1";
+demon_1(suite) -> [];
+demon_1(Config) when is_list(Config) ->
+    ?line true = erlang:demonitor(make_ref()),
+    ok.
+
+
+%%% Cases for demonitor/1
+
+demon_2(doc) ->
+    "Cases for demonitor/1";
+demon_2(suite) -> [];
+demon_2(Config) when is_list(Config) ->
+    ?line R1 = erlang:monitor(process, self()),
+    ?line true = erlang:demonitor(R1),
+    %% Extra demonitor
+    ?line true = erlang:demonitor(R1),
+    ?line expect_no_msg(),
+
+    %% Normal 'DOWN'
+    ?line P2 = spawn(timer, sleep, [1]),
+    ?line R2 = erlang:monitor(process, P2),
+    ?line case expect_down(R2, P2) of
+	      normal -> ?line ok;
+	      noproc -> ?line ok;
+	      BadReason -> ?line ?t:fail({bad_reason, BadReason})
+	  end,
+
+%% OTP-5772
+%     %% 'DOWN' before demonitor
+%     ?line P3 = spawn(timer, sleep, [100000]),
+%     ?line R3 = erlang:monitor(process, P3),
+%     ?line exit(P3, frop),
+%     ?line erlang:demonitor(R3),
+%     ?line expect_down(R3, P3, frop),
+
+    %% Demonitor before 'DOWN'
+    ?line P4 = spawn(timer, sleep, [100000]),
+    ?line R4 = erlang:monitor(process, P4),
+    ?line erlang:demonitor(R4),
+    ?line exit(P4, frop),
+    ?line expect_no_msg(),
+
+    ok.
+
+demon_3(doc) ->
+    "Distributed case for demonitor/1 (OTP-3499)";
+demon_3(suite) -> [];
+demon_3(Config) when is_list(Config) ->
+    ?line {ok, N} = test_server:start_node(hej, slave, []),
+
+    %% 'DOWN' before demonitor
+    ?line P2 = spawn(N, timer, sleep, [100000]),
+    ?line R2 = erlang:monitor(process, P2),
+    ?line true = test_server:stop_node(N),
+    ?line true = erlang:demonitor(R2),
+    ?line expect_down(R2, P2, noconnection),
+
+    ?line {ok, N2} = test_server:start_node(hej, slave, []),
+
+    %% Demonitor before 'DOWN'
+    ?line P3 = spawn(N2, timer, sleep, [100000]),
+    ?line R3 = erlang:monitor(process, P3),
+    ?line true = erlang:demonitor(R3),
+    ?line true = test_server:stop_node(N2),
+    ?line expect_no_msg(),
+
+    ok.
+
+demonitor_flush(suite) -> [];
+demonitor_flush(doc) -> [];
+demonitor_flush(Config) when is_list(Config) ->
+    ?line {'EXIT', {badarg, _}} = (catch erlang:demonitor(make_ref(), flush)),
+    ?line {'EXIT', {badarg, _}} = (catch erlang:demonitor(make_ref(), [flus])),
+    ?line {'EXIT', {badarg, _}} = (catch erlang:demonitor(x, [flush])),
+    ?line {ok, N} = test_server:start_node(demonitor_flush, slave, []),
+    ?line ok = demonitor_flush_test(N),
+    ?line true = test_server:stop_node(N),
+    ?line ok = demonitor_flush_test(node()).
+    
+demonitor_flush_test(Node) ->
+    ?line P = spawn(Node, timer, sleep, [100000]),
+    ?line M1 = erlang:monitor(process, P),
+    ?line M2 = erlang:monitor(process, P),
+    ?line M3 = erlang:monitor(process, P),
+    ?line M4 = erlang:monitor(process, P),
+    ?line true = erlang:demonitor(M1, [flush, flush]),
+    ?line exit(P, bang),
+    ?line receive {'DOWN', M2, process, P, bang} -> ok end,
+    ?line receive after 100 -> ok end,
+    ?line true = erlang:demonitor(M3, [flush]),
+    ?line true = erlang:demonitor(M4, []),
+    ?line receive {'DOWN', M4, process, P, bang} -> ok end,
+    ?line receive
+	      {'DOWN', M, _, _, _} =DM when M == M1,
+					    M == M3 ->
+		  ?line ?t:fail({unexpected_down_message, DM})
+	  after 100 ->
+		  ?line ok
+	  end.
+
+-define(RM_MON_GROUPS, 100).
+-define(RM_MON_GPROCS, 100).
+
+remove_monitor(suite) ->
+    [local_remove_monitor, remote_remove_monitor].
+
+local_remove_monitor(Config) when is_list(Config) ->
+    Gs = generate(fun () -> start_remove_monitor_group(node()) end,
+		  ?RM_MON_GROUPS),
+    {True, False} = lists:foldl(fun (G, {T, F}) ->
+					receive
+					    {rm_mon_res, G, {GT, GF}} ->
+						{T+GT, F+GF}
+					end
+				end,
+				{0, 0},
+				Gs),
+    erlang:display({local_remove_monitor, True, False}),
+    {comment,
+     "True = "++integer_to_list(True)++"; False = "++integer_to_list(False)}.
+	
+remote_remove_monitor(Config) when is_list(Config) ->
+    ?line {ok, N} = test_server:start_node(demonitor_flush, slave, []),
+    Gs = generate(fun () -> start_remove_monitor_group(node()) end,
+		  ?RM_MON_GROUPS),
+    {True, False} = lists:foldl(fun (G, {T, F}) ->
+					receive
+					    {rm_mon_res, G, {GT, GF}} ->
+						{T+GT, F+GF}
+					end
+				end,
+				{0, 0},
+				Gs),
+    erlang:display({remote_remove_monitor, True, False}),
+    ?line true = test_server:stop_node(N),
+    {comment,
+     "True = "++integer_to_list(True)++"; False = "++integer_to_list(False)}.
+
+start_remove_monitor_group(Node) ->
+    Master = self(),
+    spawn_link(
+      fun () ->
+	      Ms = generate(fun () ->
+				    P = spawn(Node, fun () -> ok end),
+				    erlang:monitor(process, P)
+			    end, ?RM_MON_GPROCS),
+	      Res = lists:foldl(fun (M, {T, F}) ->
+					case erlang:demonitor(M, [info]) of
+					    true ->
+						receive
+						    {'DOWN', M, _, _, _} ->
+							exit(down_msg_found)
+						after 0 ->
+							ok
+						end,
+						{T+1, F};
+					    false ->
+						receive
+						    {'DOWN', M, _, _, _} ->
+							ok
+						after 0 ->
+							exit(no_down_msg_found)
+						end,
+						{T, F+1}
+					end
+				end,
+				{0,0},
+				Ms),
+	      Master ! {rm_mon_res, self(), Res}
+      end).
+					  
+				      
+%%% Cases for monitor/2
+
+mon_1(doc) ->
+    "Cases for monitor/2";
+mon_1(suite) -> [];
+mon_1(Config) when is_list(Config) ->
+    %% Normal case
+    ?line P2 = spawn(timer, sleep, [1]),
+    ?line R2 = erlang:monitor(process, P2),
+    ?line case expect_down(R2, P2) of
+	      normal -> ?line ok;
+	      noproc -> ?line ok;
+	      BadReason -> ?line ?t:fail({bad_reason, BadReason})
+	  end,
+    ?line {P2A,R2A} = spawn_monitor(timer, sleep, [1]),
+    ?line expect_down(R2A, P2A, normal),
+
+    %% 'DOWN' with other reason
+    ?line P3 = spawn(timer, sleep, [100000]),
+    ?line R3 = erlang:monitor(process, P3),
+    ?line exit(P3, frop),
+    ?line expect_down(R3, P3, frop),
+    ?line {P3A,R3A} = spawn_monitor(timer, sleep, [100000]),
+    ?line exit(P3A, frop),
+    ?line expect_down(R3A, P3A, frop),
+
+    %% Monitor fails because process is dead
+    ?line R4 = erlang:monitor(process, P3),
+    ?line expect_down(R4, P3, noproc),
+
+    %% Normal case (named process)
+    ?line P5 = start_jeeves(jeeves),
+    ?line R5 = erlang:monitor(process, jeeves),
+    ?line tell_jeeves(P5, stop),
+    ?line expect_down(R5, {jeeves, node()}, normal),
+
+    %% 'DOWN' with other reason and node explicit activation
+    ?line P6 = start_jeeves(jeeves),
+    ?line R6 = erlang:monitor(process, {jeeves, node()}),
+    ?line tell_jeeves(P6, {exit, frop}),
+    ?line expect_down(R6, {jeeves, node()}, frop),
+
+    %% Monitor (named process) fails because process is dead
+    ?line R7 = erlang:monitor(process, {jeeves, node()}),
+    ?line expect_down(R7, {jeeves, node()}, noproc),
+
+    ok.
+
+mon_2(doc) ->
+    "Distributed cases for monitor/2";
+mon_2(suite) -> [];
+mon_2(Config) when is_list(Config) ->
+    ?line {ok, N1} = test_server:start_node(hej1, slave, []),
+
+    %% Normal case
+    ?line P2 = spawn(N1, timer, sleep, [4000]),
+    ?line R2 = erlang:monitor(process, P2),
+    ?line expect_down(R2, P2, normal),
+
+    %% 'DOWN' with other reason
+    ?line P3 = spawn(N1, timer, sleep, [100000]),
+    ?line R3 = erlang:monitor(process, P3),
+    ?line exit(P3, frop),
+    ?line expect_down(R3, P3, frop),
+
+    %% Monitor fails because process is dead
+    ?line R4 = erlang:monitor(process, P3),
+    ?line expect_down(R4, P3, noproc),
+
+    %% Other node goes down
+    ?line P5 = spawn(N1, timer, sleep, [100000]),
+    ?line R5 = erlang:monitor(process, P5),
+
+    ?line true = test_server:stop_node(N1),
+
+    ?line expect_down(R5, P5, noconnection),
+
+    %% Monitor fails because other node is dead
+    ?line P6 = spawn(N1, timer, sleep, [100000]),
+    ?line R6 = erlang:monitor(process, P6),
+    ?line R6_Reason = expect_down(R6, P6),
+    ?line true = (R6_Reason == noconnection) orelse (R6_Reason == noproc),
+
+    %% Start a new node that can load code in this module
+    ?line PA = filename:dirname(code:which(?MODULE)),
+    ?line {ok, N2} = test_server:start_node
+		       (hej2, slave, [{args, "-pa " ++ PA}]),
+
+    %% Normal case (named process)
+    ?line P7 = start_jeeves({jeeves, N2}),
+    ?line R7 = erlang:monitor(process, {jeeves, N2}),
+    ?line tell_jeeves(P7, stop),
+    ?line expect_down(R7, {jeeves, N2}, normal),
+
+    %% 'DOWN' with other reason (named process)
+    ?line P8 = start_jeeves({jeeves, N2}),
+    ?line R8 = erlang:monitor(process, {jeeves, N2}),
+    ?line tell_jeeves(P8, {exit, frop}),
+    ?line expect_down(R8, {jeeves, N2}, frop),
+
+    %% Monitor (named process) fails because process is dead
+    ?line R9 = erlang:monitor(process, {jeeves, N2}),
+    ?line expect_down(R9, {jeeves, N2}, noproc),
+
+    %% Other node goes down (named process)
+    ?line _P10 = start_jeeves({jeeves, N2}),
+    ?line R10 = erlang:monitor(process, {jeeves, N2}),
+
+    ?line true = test_server:stop_node(N2),
+
+    ?line expect_down(R10, {jeeves, N2}, noconnection),
+
+    %% Monitor (named process) fails because other node is dead
+    ?line R11 = erlang:monitor(process, {jeeves, N2}),
+    ?line expect_down(R11, {jeeves, N2}, noconnection),
+
+    ok.
+
+%%% Large exit reason. Crashed first attempt to release R5B.
+
+large_exit(doc) ->
+    "Large exit reason";
+large_exit(suite) -> [];
+large_exit(Config) when is_list(Config) ->
+    ?line f(100),
+    ok.
+
+f(0) ->
+    ok;
+f(N) ->
+    f(),
+    f(N-1).
+
+f() ->
+    ?line S0 = {big, tuple, with, [list, 4563784278]},
+    ?line S = {S0, term_to_binary(S0)},
+    ?line P = spawn(?MODULE, large_exit_sub, [S]),
+    ?line R = erlang:monitor(process, P),
+    ?line P ! hej,
+    receive
+	{'DOWN', R, process, P, X} ->
+	    ?line io:format(" -> ~p~n", [X]),
+	    if
+		X == S ->
+		    ok;
+		true ->
+		    test_server:fail({X, S})
+	    end;
+	Other ->
+	    ?line io:format(" -> ~p~n", [Other]),
+	    exit({answer, Other})
+    end.
+
+large_exit_sub(S) ->
+    receive _X -> ok end,
+    exit(S).
+
+%%% Testing of monitor link list cleanup
+%%% by using erlang:process_info(self(), monitors)
+%%% and      erlang:process_info(self(), monitored_by)
+
+list_cleanup(doc) ->
+    "Testing of monitor link list cleanup by using " ++
+    "erlang:process_info/2";
+list_cleanup(suite) -> [];
+list_cleanup(Config) when is_list(Config) ->
+    ?line P0 = self(),
+    ?line M  = node(),
+    ?line PA = filename:dirname(code:which(?MODULE)),
+    ?line true = register(master_bertie, self()),
+
+    %% Normal local case, monitor and demonitor
+    ?line P1 = start_jeeves(jeeves),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P1, monitors, {monitors, {[], []}}),
+    ?line R1a = erlang:monitor(process, P1),
+    ?line {[{process, P1}], []} = monitors(),
+    ?line expect_jeeves(P1, monitors, {monitors, {[], [P0]}}),
+    ?line true = erlang:demonitor(R1a),
+    ?line expect_no_msg(),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P1, monitors, {monitors, {[], []}}),
+    %% Remonitor named and try again, now exiting the monitored process
+    ?line R1b = erlang:monitor(process, jeeves),
+    ?line {[{process, {jeeves, M}}], []} = monitors(),
+    ?line expect_jeeves(P1, monitors, {monitors, {[], [P0]}}),
+    ?line tell_jeeves(P1, stop),
+    ?line expect_down(R1b, {jeeves, node()}, normal),
+    ?line {[], []} = monitors(),
+
+    %% Slightly weird local case - the monitoring process crashes
+    ?line P2 = start_jeeves(jeeves),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P2, monitors, {monitors, {[], []}}),
+    ?line {monitor_process, _R2} = 
+	ask_jeeves(P2, {monitor_process, master_bertie}),
+    ?line {[], [P2]} = monitors(),
+    ?line expect_jeeves(P2, monitors,
+			{monitors, {[{process, {master_bertie, node()}}], []}}),
+    ?line tell_jeeves(P2, {exit, frop}),
+    timer:sleep(2000),
+    ?line {[], []} = monitors(),
+
+    %% Start a new node that can load code in this module
+    ?line {ok, J} = test_server:start_node
+		       (jeeves, slave, [{args, "-pa " ++ PA}]),
+
+    %% Normal remote case, monitor and demonitor
+    ?line P3 = start_jeeves({jeeves, J}),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P3, monitors, {monitors, {[], []}}),
+    ?line R3a = erlang:monitor(process, P3),
+    ?line {[{process, P3}], []} = monitors(),
+    ?line expect_jeeves(P3, monitors, {monitors, {[], [P0]}}),
+    ?line true = erlang:demonitor(R3a),
+    ?line expect_no_msg(),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P3, monitors, {monitors, {[], []}}),
+    %% Remonitor named and try again, now exiting the monitored process
+    ?line R3b = erlang:monitor(process, {jeeves, J}),
+    ?line {[{process, {jeeves, J}}], []} = monitors(),
+    ?line expect_jeeves(P3, monitors, {monitors, {[], [P0]}}),
+    ?line tell_jeeves(P3, stop),
+    ?line expect_down(R3b, {jeeves, J}, normal),
+    ?line {[], []} = monitors(),
+
+    %% Slightly weird remote case - the monitoring process crashes
+    ?line P4 = start_jeeves({jeeves, J}),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P4, monitors, {monitors, {[], []}}),
+    ?line {monitor_process, _R4} = 
+	ask_jeeves(P4, {monitor_process, {master_bertie, M}}),
+    ?line {[], [P4]} = monitors(),
+    ?line expect_jeeves(P4, monitors, 
+			{monitors, {[{process, {master_bertie, M}}], []}} ),
+    ?line tell_jeeves(P4, {exit, frop}),
+    timer:sleep(2000),
+    ?line {[], []} = monitors(),
+    
+    %% Now, the monitoring remote node crashes
+    ?line P5 = start_jeeves({jeeves, J}),
+    ?line {[], []} = monitors(),
+    ?line expect_jeeves(P5, monitors, {monitors, {[], []}}),
+    ?line {monitor_process, _R5} = 
+	ask_jeeves(P5, {monitor_process, P0}),
+    ?line {[], [P5]} = monitors(),
+    ?line expect_jeeves(P5, monitors, 
+			{monitors, {[{process, P0}], []}} ),
+    ?line test_server:stop_node(J),
+    timer:sleep(4000),
+    ?line {[], []} = monitors(),
+    
+    ?line true = unregister(master_bertie),
+    ok.
+
+    
+%%% Mixed internal and external monitors
+
+mixer(doc) ->
+    "Test mixing of internal and external monitors.";
+mixer(Config) when is_list(Config) ->
+    ?line PA = filename:dirname(code:which(?MODULE)),
+    ?line NN = [j0,j1,j2,j3],
+%    ?line NN = [j0,j1],
+    ?line NL0 = [begin
+		    {ok, J} = test_server:start_node
+				(X, slave, [{args, "-pa " ++ PA}]), 
+		    J 
+		end  || X <- NN],
+    ?line NL1 = lists:duplicate(2,node()) ++ NL0,
+    ?line Perm = perm(NL1),
+    ?line lists:foreach(
+	    fun(NL) ->
+		    ?line Js = [ start_jeeves({[],M}) || M <- (NL ++ NL) ],
+		    ?line [ask_jeeves(P,{monitor_process,self()}) || P <- Js],
+		    ?line {monitored_by,MB} = 
+			process_info(self(),monitored_by),
+		    ?line MBL = lists:sort(MB),
+		    ?line JsL = lists:sort(Js),
+		    ?line MBL = JsL,
+		    ?line {monitors,[]}  = process_info(self(),monitors),
+		    ?line [tell_jeeves(P,{exit,flaff}) || P <- Js],
+		    ?line wait_for_m([],[],200)
+	    end,
+	    Perm),
+    ?line lists:foreach(
+	    fun(NL) ->
+		    ?line Js = [ start_jeeves({[],M}) || M <- (NL ++ NL) ],
+		    ?line Rs = [begin
+				    {monitor_process,Ref} = 
+					ask_jeeves(P,{monitor_process,self()}),
+				    {P,Ref}
+				end
+				|| P <- Js],
+		    ?line {monitored_by,MB} = 
+			process_info(self(),monitored_by),
+		    ?line MBL = lists:sort(MB),
+		    ?line JsL = lists:sort(Js),
+		    ?line MBL = JsL,
+		    ?line {monitors,[]}  = process_info(self(),monitors),
+		    ?line [ask_jeeves(P,{demonitor,Ref}) || {P,Ref} <- Rs],
+		    ?line wait_for_m([],[],200),
+		    ?line [tell_jeeves(P,{exit,flaff}) || P <- Js]
+	    end,
+	    Perm),
+    ?line lists:foreach(
+	    fun(NL) ->
+		    ?line Js = [ start_jeeves({[],M}) || M <- (NL ++ NL) ],
+		    ?line [ask_jeeves(P,{monitor_process,self()}) || P <- Js],
+		    ?line [erlang:monitor(process,P) || P <- Js],
+		    ?line {monitored_by,MB} = 
+			process_info(self(),monitored_by),
+		    ?line MBL = lists:sort(MB),
+		    ?line JsL = lists:sort(Js),
+		    ?line MBL = JsL,
+		    ?line {monitors,M} = 
+			process_info(self(),monitors),
+		    ?line ML = lists:sort([P||{process,P} <- M]),
+		    ?line ML = JsL,
+		    ?line [begin
+			       tell_jeeves(P,{exit,flaff}),
+			       receive {'DOWN',_,process,P,_} -> ok end
+			   end || P <- Js],
+		    ?line wait_for_m([],[],200)
+	    end,
+	    Perm),
+    ?line lists:foreach(
+	    fun(NL) ->
+		    ?line Js = [ start_jeeves({[],M}) || M <- (NL ++ NL) ],
+		    ?line Rs = [begin
+				    {monitor_process,Ref} = 
+					ask_jeeves(P,{monitor_process,self()}),
+				    {P,Ref}
+				end
+				|| P <- Js],
+		    ?line R2s = [{P,erlang:monitor(process,P)} || P <- Js],
+		    ?line {monitored_by,MB} = 
+			process_info(self(),monitored_by),
+		    ?line MBL = lists:sort(MB),
+		    ?line JsL = lists:sort(Js),
+		    ?line MBL = JsL,
+		    ?line {monitors,M} = 
+			process_info(self(),monitors),
+		    ?line ML = lists:sort([P||{process,P} <- M]),
+		    ?line ML = JsL,
+		    ?line [ask_jeeves(P,{demonitor,Ref}) || {P,Ref} <- Rs],
+		    ?line wait_for_m(lists:sort(M),[],200),
+		    ?line [erlang:demonitor(Ref) || {_P,Ref} <- R2s],
+		    ?line wait_for_m([],[],200),
+		    ?line [tell_jeeves(P,{exit,flaff}) || P <- Js]
+	    end,
+	    Perm),
+    [test_server:stop_node(K) || K <- NL0 ],
+    ok.
+
+named_down(doc) -> ["Test that DOWN message for a named monitor isn't"
+		    " delivered until name has been unregistered"];
+named_down(suite) -> [];
+named_down(Config) when is_list(Config) ->
+    ?line {A,B,C} = now(),
+    ?line Name = list_to_atom(atom_to_list(?MODULE)
+			      ++ "-named_down-"
+			      ++ integer_to_list(A)
+			      ++ "-" ++ integer_to_list(B)
+			      ++ "-" ++ integer_to_list(C)),
+    ?line Prio = process_flag(priority,high),
+    %% Spawn a bunch of high prio cpu bound processes to prevent
+    %% normal prio processes from terminating during the next
+    %% 500 ms...
+    ?line Self = self(),
+    ?line spawn_opt(fun () ->
+			    WFun = fun
+				       (F, hej) -> F(F, hopp);
+				       (F, hopp) -> F(F, hej)
+				   end,
+			    NoSchedulers = erlang:system_info(schedulers_online),
+			    lists:foreach(fun (_) ->
+						  spawn_opt(fun () ->
+								    WFun(WFun,
+									 hej)
+							    end,
+							    [{priority,high},
+							     link])
+					  end,
+					  lists:seq(1, NoSchedulers)),
+			    receive after 500 -> ok end,
+			    unlink(Self),
+			    exit(bang)
+		     end,
+		    [{priority,high}, link]),
+    ?line NamedProc = spawn_link(fun () ->
+					 receive after infinity -> ok end
+				 end),
+    ?line true = register(Name, NamedProc),
+    ?line unlink(NamedProc),
+    ?line exit(NamedProc, bang),
+    ?line Mon = erlang:monitor(process, Name),
+    ?line receive {'DOWN',Mon, _, _, _} -> ok end,
+    ?line true = register(Name, self()),
+    ?line true = unregister(Name),
+    ?line process_flag(priority,Prio),
+    ok.
+
+otp_5827(doc) -> [];
+otp_5827(suite) -> [];
+otp_5827(Config) when is_list(Config) ->
+    %% Make a pid with the same nodename but with another creation
+    ?line [CreEnd | RPTail]
+	= lists:reverse(binary_to_list(term_to_binary(self()))),
+    ?line NewCreEnd = case CreEnd of
+		    0 -> 1;
+		    1 -> 2;
+		    _ -> CreEnd - 1
+		end,
+    ?line OtherCreationPid
+	= binary_to_term(list_to_binary(lists:reverse([NewCreEnd | RPTail]))),
+    %% If the bug is present erlang:monitor(process, OtherCreationPid)
+    %% will hang...
+    ?line Parent = self(),
+    ?line Ok = make_ref(),
+    ?line spawn(fun () ->
+			Mon = erlang:monitor(process, OtherCreationPid),
+			% Should get the DOWN message right away
+			receive
+			    {'DOWN', Mon, process, OtherCreationPid, noproc} ->
+				Parent ! Ok
+			end
+		end),
+    ?line receive
+	      Ok ->
+		  ?line ok
+	  after 1000 ->
+		  ?line ?t:fail("erlang:monitor/2 hangs")
+	  end.
+
+
+wait_for_m(_,_,0) ->
+    exit(monitor_wait_timeout);
+wait_for_m(Monitors, MonitoredBy, N) ->
+    {monitors,M0}  = process_info(self(),monitors),
+    {monitored_by,MB0} = process_info(self(),monitored_by),
+    case lists:sort(M0) of
+	Monitors ->
+	    case lists:sort(MB0) of
+		MonitoredBy ->
+		    ok;
+		_ ->
+		    receive after 100 -> ok end,
+		    wait_for_m(Monitors,MonitoredBy,N-1)
+	    end;
+	_ ->
+	    receive after 100 -> ok end,
+	    wait_for_m(Monitors,MonitoredBy,N-1)
+    end.
+
+% All permutations of a list...
+perm([]) ->
+    [];
+perm([X]) ->
+    [[X]];
+perm(List) ->
+    perm([],List,[]).
+
+perm(_,[],Acc) ->
+    Acc;
+perm(Pre,[El|Post],Acc) ->
+    Res = [[El|X] || X <- perm(Pre ++ Post)],
+    perm(Pre ++ [El], Post, Res ++ Acc).
+
+
+%%% Our butler for named process monitor tests
+
+jeeves(Parent, Name, Ref) 
+  when is_pid(Parent), (is_atom(Name) or (Name =:= [])), is_reference(Ref) ->
+    %%io:format("monitor_SUITE:jeeves(~p, ~p)~n", [Parent, Name]),
+    case Name of
+	Atom when is_atom(Atom) ->
+	    register(Name, self());
+	[] ->
+	    ok
+    end,
+    Parent ! {self(), Ref},
+    jeeves_loop(Parent).
+
+jeeves_loop(Parent) ->
+    receive
+	{Parent, monitors} ->
+	    Parent ! {self(), {monitors, monitors()}},
+	    jeeves_loop(Parent);
+	{Parent, {monitor_process, P}} ->
+	    Parent ! {self(), {monitor_process, 
+			       catch erlang:monitor(process, P) }},
+	    jeeves_loop(Parent);
+	{Parent, {demonitor, Ref}} ->
+	    Parent ! {self(), {demonitor, catch erlang:demonitor(Ref)}},
+	    jeeves_loop(Parent);
+	{Parent, stop} ->
+	    ok;
+	{Parent, {exit, Reason}} ->
+	    exit(Reason);
+	Other ->
+	    io:format("~p:jeeves_loop received ~p~n", [?MODULE, Other])
+    end.
+
+
+start_jeeves({Name, Node}) 
+  when (is_atom(Name) or (Name =:= [])), is_atom(Node) ->
+    Parent = self(),
+    Ref = make_ref(),
+    Pid = spawn(Node, fun() -> jeeves(Parent, Name, Ref) end),
+    receive 
+	{Pid, Ref} -> 
+	    ok;
+	Other ->
+	    test_server:fail({rec, Other})
+    end,
+    Pid;
+start_jeeves(Name) when is_atom(Name) ->
+    start_jeeves({Name, node()}).
+
+
+tell_jeeves(Pid, What) when is_pid(Pid) ->
+    Pid ! {self(), What}.
+
+
+ask_jeeves(Pid, Request) when is_pid(Pid) ->
+    Pid ! {self(), Request},
+    receive
+	{Pid, Response} ->
+	    Response;
+	Other ->
+	    test_server:fail({rec, Other})
+    end.
+
+
+expect_jeeves(Pid, Request, Response) when is_pid(Pid) ->
+    Pid ! {self(), Request},
+    receive 
+	{Pid, Response} -> 
+	    ok;
+	Other ->
+	    test_server:fail({rec, Other})
+    end.
+
+
+monitors() ->
+    monitors(self()).
+
+monitors(Pid) when is_pid(Pid) ->
+    {monitors, Monitors}          = process_info(self(), monitors),
+    {monitored_by,  MonitoredBy}  = process_info(self(), monitored_by),
+    {Monitors, MonitoredBy}.
+
+generate(_Fun, 0) ->
+    [];
+generate(Fun, N) ->
+    [Fun() | generate(Fun, N-1)].