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-rw-r--r--lib/kernel/src/auth.erl12
-rw-r--r--lib/stdlib/doc/src/supervisor.xml12
-rw-r--r--lib/stdlib/src/supervisor.erl170
-rw-r--r--lib/stdlib/test/Makefile1
-rw-r--r--lib/stdlib/test/supervisor_SUITE.erl122
-rw-r--r--lib/stdlib/test/supervisor_deadlock.erl45
6 files changed, 302 insertions, 60 deletions
diff --git a/lib/kernel/src/auth.erl b/lib/kernel/src/auth.erl
index c329a5652a..252c20ac4e 100644
--- a/lib/kernel/src/auth.erl
+++ b/lib/kernel/src/auth.erl
@@ -381,13 +381,17 @@ create_cookie(Name) ->
case {R1, R2} of
{ok, ok} ->
ok;
- {{error,_Reason}, _} ->
- {error, "Failed to create cookie file"};
+ {{error,Reason}, _} ->
+ {error,
+ lists:flatten(
+ io_lib:format("Failed to write to cookie file '~s': ~p", [Name, Reason]))};
{ok, {error, Reason}} ->
{error, "Failed to change mode: " ++ atom_to_list(Reason)}
end;
- {error,_Reason} ->
- {error, "Failed to create cookie file"}
+ {error,Reason} ->
+ {error,
+ lists:flatten(
+ io_lib:format("Failed to create cookie file '~s': ~p", [Name, Reason]))}
end.
random_cookie(0, _, Result) ->
diff --git a/lib/stdlib/doc/src/supervisor.xml b/lib/stdlib/doc/src/supervisor.xml
index d1e62230bc..35f4f82264 100644
--- a/lib/stdlib/doc/src/supervisor.xml
+++ b/lib/stdlib/doc/src/supervisor.xml
@@ -399,10 +399,11 @@ child_spec() = {Id,StartFunc,Restart,Shutdown,Type,Modules}
<c>SupRef</c>.</p>
<p>If successful, the function returns <c>ok</c>. If the child
specification identified by <c><anno>Id</anno></c> exists but
- the corresponding child process is running, the function
- returns <c>{error,running}</c>. If the child specification
- identified by <c><anno>Id</anno></c> does not exist, the function returns
- <c>{error,not_found}</c>.</p>
+ the corresponding child process is running or about to be restarted,
+ the function returns <c>{error,running}</c> or
+ <c>{error,restarting}</c> respectively. If the child specification
+ identified by <c><anno>Id</anno></c> does not exist, the function
+ returns <c>{error,not_found}</c>.</p>
</desc>
</func>
<func>
@@ -462,7 +463,8 @@ child_spec() = {Id,StartFunc,Restart,Shutdown,Type,Modules}
</item>
<item>
<p><c><anno>Child</anno></c> - the pid of the corresponding child
- process, or <c>undefined</c> if there is no such process.</p>
+ process, the atom <c>restarting</c> if the process is about to be
+ restarted or <c>undefined</c> if there is no such process.</p>
</item>
<item>
<p><c><anno>Type</anno></c> - as defined in the child specification.</p>
diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl
index ac5b078c29..f315064b03 100644
--- a/lib/stdlib/src/supervisor.erl
+++ b/lib/stdlib/src/supervisor.erl
@@ -28,8 +28,9 @@
check_childspecs/1]).
%% Internal exports
--export([init/1, handle_call/3, handle_info/2, terminate/2, code_change/3]).
--export([handle_cast/2]).
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+ terminate/2, code_change/3]).
+-export([try_again_restart/2]).
%%--------------------------------------------------------------------------
@@ -37,7 +38,7 @@
%%--------------------------------------------------------------------------
--type child() :: 'undefined' | pid() | [pid()].
+-type child() :: 'undefined' | pid().
-type child_id() :: term().
-type mfargs() :: {M :: module(), F :: atom(), A :: [term()] | undefined}.
-type modules() :: [module()] | 'dynamic'.
@@ -62,8 +63,8 @@
%%--------------------------------------------------------------------------
-record(child, {% pid is undefined when child is not running
- pid = undefined :: child(),
- name,
+ pid = undefined :: child() | {restarting,pid()} | [pid()],
+ name :: child_id(),
mfargs :: mfargs(),
restart_type :: restart(),
shutdown :: shutdown(),
@@ -95,6 +96,8 @@
[ChildSpec :: child_spec()]}}
| ignore.
+-define(restarting(_Pid_), {restarting,_Pid_}).
+
%%% ---------------------------------------------------
%%% This is a general process supervisor built upon gen_server.erl.
%%% Servers/processes should/could also be built using gen_server.erl.
@@ -139,7 +142,8 @@ start_child(Supervisor, ChildSpec) ->
Result :: {'ok', Child :: child()}
| {'ok', Child :: child(), Info :: term()}
| {'error', Error},
- Error :: 'running' | 'not_found' | 'simple_one_for_one' | term().
+ Error :: 'running' | 'restarting' | 'not_found' | 'simple_one_for_one' |
+ term().
restart_child(Supervisor, Name) ->
call(Supervisor, {restart_child, Name}).
@@ -147,7 +151,7 @@ restart_child(Supervisor, Name) ->
SupRef :: sup_ref(),
Id :: child_id(),
Result :: 'ok' | {'error', Error},
- Error :: 'running' | 'not_found' | 'simple_one_for_one'.
+ Error :: 'running' | 'restarting' | 'not_found' | 'simple_one_for_one'.
delete_child(Supervisor, Name) ->
call(Supervisor, {delete_child, Name}).
@@ -169,7 +173,7 @@ terminate_child(Supervisor, Name) ->
-spec which_children(SupRef) -> [{Id,Child,Type,Modules}] when
SupRef :: sup_ref(),
Id :: child_id() | undefined,
- Child :: child(),
+ Child :: child() | 'restarting',
Type :: worker(),
Modules :: modules().
which_children(Supervisor) ->
@@ -198,6 +202,17 @@ check_childspecs(ChildSpecs) when is_list(ChildSpecs) ->
end;
check_childspecs(X) -> {error, {badarg, X}}.
+%%%-----------------------------------------------------------------
+%%% Called by timer:apply_after from restart/2
+-spec try_again_restart(SupRef, Child) -> ok when
+ SupRef :: sup_ref(),
+ Child :: child_id() | pid().
+try_again_restart(Supervisor, Child) ->
+ cast(Supervisor, {try_again_restart, Child}).
+
+cast(Supervisor, Req) ->
+ gen_server:cast(Supervisor, Req).
+
%%% ---------------------------------------------------
%%%
%%% Initialize the supervisor.
@@ -384,6 +399,8 @@ handle_call({restart_child, Name}, _From, State) ->
Error ->
{reply, Error, State}
end;
+ {value, #child{pid=?restarting(_)}} ->
+ {reply, {error, restarting}, State};
{value, _} ->
{reply, {error, running}, State};
_ ->
@@ -395,6 +412,8 @@ handle_call({delete_child, Name}, _From, State) ->
{value, Child} when Child#child.pid =:= undefined ->
NState = remove_child(Child, State),
{reply, ok, NState};
+ {value, #child{pid=?restarting(_)}} ->
+ {reply, {error, restarting}, State};
{value, _} ->
{reply, {error, running}, State};
_ ->
@@ -413,13 +432,17 @@ handle_call(which_children, _From, #state{children = [#child{restart_type = RTyp
child_type = CT,
modules = Mods}]} =
State) when ?is_simple(State) ->
- Reply = lists:map(fun({Pid, _}) -> {undefined, Pid, CT, Mods} end,
+ Reply = lists:map(fun({?restarting(_),_}) -> {undefined,restarting,CT,Mods};
+ ({Pid, _}) -> {undefined, Pid, CT, Mods} end,
?DICT:to_list(dynamics_db(RType, State#state.dynamics))),
{reply, Reply, State};
handle_call(which_children, _From, State) ->
Resp =
- lists:map(fun(#child{pid = Pid, name = Name,
+ lists:map(fun(#child{pid = ?restarting(_), name = Name,
+ child_type = ChildType, modules = Mods}) ->
+ {Name, restarting, ChildType, Mods};
+ (#child{pid = Pid, name = Name,
child_type = ChildType, modules = Mods}) ->
{Name, Pid, ChildType, Mods}
end,
@@ -432,8 +455,11 @@ handle_call(count_children, _From, #state{children = [#child{restart_type = temp
when ?is_simple(State) ->
{Active, Count} =
?SETS:fold(fun(Pid, {Alive, Tot}) ->
- if is_pid(Pid) -> {Alive+1, Tot +1};
- true -> {Alive, Tot + 1} end
+ case is_pid(Pid) andalso is_process_alive(Pid) of
+ true ->{Alive+1, Tot +1};
+ false ->
+ {Alive, Tot + 1}
+ end
end, {0, 0}, dynamics_db(temporary, State#state.dynamics)),
Reply = case CT of
supervisor -> [{specs, 1}, {active, Active},
@@ -448,8 +474,12 @@ handle_call(count_children, _From, #state{children = [#child{restart_type = RTy
when ?is_simple(State) ->
{Active, Count} =
?DICT:fold(fun(Pid, _Val, {Alive, Tot}) ->
- if is_pid(Pid) -> {Alive+1, Tot +1};
- true -> {Alive, Tot + 1} end
+ case is_pid(Pid) andalso is_process_alive(Pid) of
+ true ->
+ {Alive+1, Tot +1};
+ false ->
+ {Alive, Tot + 1}
+ end
end, {0, 0}, dynamics_db(RType, State#state.dynamics)),
Reply = case CT of
supervisor -> [{specs, 1}, {active, Active},
@@ -486,14 +516,42 @@ count_child(#child{pid = Pid, child_type = supervisor},
end.
-%%% Hopefully cause a function-clause as there is no API function
-%%% that utilizes cast.
--spec handle_cast('null', state()) -> {'noreply', state()}.
+%%% If a restart attempt failed, this message is sent via
+%%% timer:apply_after(0,...) in order to give gen_server the chance to
+%%% check it's inbox before trying again.
+-spec handle_cast({try_again_restart, child_id() | pid()}, state()) ->
+ {'noreply', state()} | {stop, shutdown, state()}.
-handle_cast(null, State) ->
- error_logger:error_msg("ERROR: Supervisor received cast-message 'null'~n",
- []),
- {noreply, State}.
+handle_cast({try_again_restart,Pid}, #state{children=[Child]}=State)
+ when ?is_simple(State) ->
+ RT = Child#child.restart_type,
+ RPid = restarting(Pid),
+ case dynamic_child_args(RPid, dynamics_db(RT, State#state.dynamics)) of
+ {ok, Args} ->
+ {M, F, _} = Child#child.mfargs,
+ NChild = Child#child{pid = RPid, mfargs = {M, F, Args}},
+ case restart(NChild,State) of
+ {ok, State1} ->
+ {noreply, State1};
+ {shutdown, State1} ->
+ {stop, shutdown, State1}
+ end;
+ error ->
+ {noreply, State}
+ end;
+
+handle_cast({try_again_restart,Name}, State) ->
+ case lists:keyfind(Name,#child.name,State#state.children) of
+ Child = #child{pid=?restarting(_)} ->
+ case restart(Child,State) of
+ {ok, State1} ->
+ {noreply, State1};
+ {shutdown, State1} ->
+ {stop, shutdown, State1}
+ end;
+ _ ->
+ {noreply,State}
+ end.
%%
%% Take care of terminated children.
@@ -624,7 +682,7 @@ handle_start_child(Child, State) ->
{error, What} ->
{{error, {What, Child}}, State}
end;
- {value, OldChild} when OldChild#child.pid =/= undefined ->
+ {value, OldChild} when is_pid(OldChild#child.pid) ->
{{error, {already_started, OldChild#child.pid}}, State};
{value, _OldChild} ->
{{error, already_present}, State}
@@ -678,7 +736,21 @@ do_restart(temporary, Reason, Child, State) ->
restart(Child, State) ->
case add_restart(State) of
{ok, NState} ->
- restart(NState#state.strategy, Child, NState);
+ case restart(NState#state.strategy, Child, NState) of
+ {try_again,NState2} ->
+ %% Leaving control back to gen_server before
+ %% trying again. This way other incoming requsts
+ %% for the supervisor can be handled - e.g. a
+ %% shutdown request for the supervisor or the
+ %% child.
+ Id = if ?is_simple(State) -> Child#child.pid;
+ true -> Child#child.name
+ end,
+ timer:apply_after(0,?MODULE,try_again_restart,[self(),Id]),
+ {ok,NState2};
+ Other ->
+ Other
+ end;
{terminate, NState} ->
report_error(shutdown, reached_max_restart_intensity,
Child, State#state.name),
@@ -686,9 +758,9 @@ restart(Child, State) ->
end.
restart(simple_one_for_one, Child, State) ->
- #child{mfargs = {M, F, A}} = Child,
- Dynamics = ?DICT:erase(Child#child.pid, dynamics_db(Child#child.restart_type,
- State#state.dynamics)),
+ #child{pid = OldPid, mfargs = {M, F, A}} = Child,
+ Dynamics = ?DICT:erase(OldPid, dynamics_db(Child#child.restart_type,
+ State#state.dynamics)),
case do_start_child_i(M, F, A) of
{ok, Pid} ->
NState = State#state{dynamics = ?DICT:store(Pid, A, Dynamics)},
@@ -697,10 +769,13 @@ restart(simple_one_for_one, Child, State) ->
NState = State#state{dynamics = ?DICT:store(Pid, A, Dynamics)},
{ok, NState};
{error, Error} ->
+ NState = State#state{dynamics = ?DICT:store(restarting(OldPid), A,
+ Dynamics)},
report_error(start_error, Error, Child, State#state.name),
- restart(Child, State)
+ {try_again, NState}
end;
restart(one_for_one, Child, State) ->
+ OldPid = Child#child.pid,
case do_start_child(State#state.name, Child) of
{ok, Pid} ->
NState = replace_child(Child#child{pid = Pid}, State),
@@ -709,8 +784,9 @@ restart(one_for_one, Child, State) ->
NState = replace_child(Child#child{pid = Pid}, State),
{ok, NState};
{error, Reason} ->
+ NState = replace_child(Child#child{pid = restarting(OldPid)}, State),
report_error(start_error, Reason, Child, State#state.name),
- restart(Child, State)
+ {try_again, NState}
end;
restart(rest_for_one, Child, State) ->
{ChAfter, ChBefore} = split_child(Child#child.pid, State#state.children),
@@ -719,7 +795,9 @@ restart(rest_for_one, Child, State) ->
{ok, ChAfter3} ->
{ok, State#state{children = ChAfter3 ++ ChBefore}};
{error, ChAfter3} ->
- restart(Child, State#state{children = ChAfter3 ++ ChBefore})
+ NChild = Child#child{pid=restarting(Child#child.pid)},
+ NState = State#state{children = ChAfter3 ++ ChBefore},
+ {try_again, replace_child(NChild,NState)}
end;
restart(one_for_all, Child, State) ->
Children1 = del_child(Child#child.pid, State#state.children),
@@ -728,9 +806,14 @@ restart(one_for_all, Child, State) ->
{ok, NChs} ->
{ok, State#state{children = NChs}};
{error, NChs} ->
- restart(Child, State#state{children = NChs})
+ NChild = Child#child{pid=restarting(Child#child.pid)},
+ NState = State#state{children = NChs},
+ {try_again, replace_child(NChild,NState)}
end.
+restarting(Pid) when is_pid(Pid) -> ?restarting(Pid);
+restarting(RPid) -> RPid.
+
%%-----------------------------------------------------------------
%% Func: terminate_children/2
%% Args: Children = [child_rec()] in termination order
@@ -754,7 +837,7 @@ terminate_children([Child | Children], SupName, Res) ->
terminate_children([], _SupName, Res) ->
Res.
-do_terminate(Child, SupName) when Child#child.pid =/= undefined ->
+do_terminate(Child, SupName) when is_pid(Child#child.pid) ->
case shutdown(Child#child.pid, Child#child.shutdown) of
ok ->
ok;
@@ -765,7 +848,7 @@ do_terminate(Child, SupName) when Child#child.pid =/= undefined ->
end,
Child#child{pid = undefined};
do_terminate(Child, _SupName) ->
- Child.
+ Child#child{pid = undefined}.
%%-----------------------------------------------------------------
%% Shutdowns a child. We must check the EXIT value
@@ -866,7 +949,7 @@ terminate_dynamic_children(Child, Dynamics, SupName) ->
TRef = erlang:start_timer(Time, self(), kill),
wait_dynamic_children(Child, Pids, Sz, TRef, EStack0)
end,
- %% Unrool stacked errors and report them
+ %% Unroll stacked errors and report them
?DICT:fold(fun(Reason, Ls, _) ->
report_error(shutdown_error, Reason,
Child#child{pid=Ls}, SupName)
@@ -885,7 +968,7 @@ monitor_dynamic_children(#child{restart_type=temporary}, Dynamics) ->
end
end, {?SETS:new(), ?DICT:new()}, Dynamics);
monitor_dynamic_children(#child{restart_type=RType}, Dynamics) ->
- ?DICT:fold(fun(P, _, {Pids, EStack}) ->
+ ?DICT:fold(fun(P, _, {Pids, EStack}) when is_pid(P) ->
case monitor_child(P) of
ok ->
{?SETS:add_element(P, Pids), EStack};
@@ -893,7 +976,9 @@ monitor_dynamic_children(#child{restart_type=RType}, Dynamics) ->
{Pids, EStack};
{error, Reason} ->
{Pids, ?DICT:append(Reason, P, EStack)}
- end
+ end;
+ (?restarting(_), _, {Pids, EStack}) ->
+ {Pids, EStack}
end, {?SETS:new(), ?DICT:new()}, Dynamics).
@@ -1020,13 +1105,20 @@ get_child(Name, State, _) ->
lists:keysearch(Name, #child.name, State#state.children).
get_dynamic_child(Pid, #state{children=[Child], dynamics=Dynamics}) ->
- case is_dynamic_pid(Pid, dynamics_db(Child#child.restart_type, Dynamics)) of
+ DynamicsDb = dynamics_db(Child#child.restart_type, Dynamics),
+ case is_dynamic_pid(Pid, DynamicsDb) of
true ->
{value, Child#child{pid=Pid}};
false ->
- case erlang:is_process_alive(Pid) of
- true -> false;
- false -> {value, Child}
+ RPid = restarting(Pid),
+ case is_dynamic_pid(RPid, DynamicsDb) of
+ true ->
+ {value, Child#child{pid=RPid}};
+ false ->
+ case erlang:is_process_alive(Pid) of
+ true -> false;
+ false -> {value, Child}
+ end
end
end.
diff --git a/lib/stdlib/test/Makefile b/lib/stdlib/test/Makefile
index b36265302c..4de6ea3ee7 100644
--- a/lib/stdlib/test/Makefile
+++ b/lib/stdlib/test/Makefile
@@ -67,6 +67,7 @@ MODULES= \
string_SUITE \
supervisor_1 \
supervisor_2 \
+ supervisor_deadlock \
naughty_child \
shell_SUITE \
supervisor_SUITE \
diff --git a/lib/stdlib/test/supervisor_SUITE.erl b/lib/stdlib/test/supervisor_SUITE.erl
index 71b76c093f..767ae3d62c 100644
--- a/lib/stdlib/test/supervisor_SUITE.erl
+++ b/lib/stdlib/test/supervisor_SUITE.erl
@@ -21,7 +21,7 @@
-module(supervisor_SUITE).
-include_lib("common_test/include/ct.hrl").
--define(TIMEOUT, 1000).
+-define(TIMEOUT, ?t:minutes(1)).
%% Testserver specific export
-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
@@ -62,7 +62,8 @@
do_not_save_start_parameters_for_temporary_children/1,
do_not_save_child_specs_for_temporary_children/1,
simple_one_for_one_scale_many_temporary_children/1,
- simple_global_supervisor/1]).
+ simple_global_supervisor/1, hanging_restart_loop/1,
+ hanging_restart_loop_simple/1]).
%%-------------------------------------------------------------------------
@@ -82,7 +83,7 @@ all() ->
count_children_memory, do_not_save_start_parameters_for_temporary_children,
do_not_save_child_specs_for_temporary_children,
simple_one_for_one_scale_many_temporary_children, temporary_bystander,
- simple_global_supervisor].
+ simple_global_supervisor, hanging_restart_loop, hanging_restart_loop_simple].
groups() ->
[{sup_start, [],
@@ -111,10 +112,8 @@ groups() ->
{restart_rest_for_one, [],
[rest_for_one, rest_for_one_escalation]}].
-init_per_suite(Config0) ->
- Config = lists:keydelete(watchdog, 1, Config0),
- Dog = test_server:timetrap(?TIMEOUT),
- [{watchdog, Dog} | Config].
+init_per_suite(Config) ->
+ Config.
end_per_suite(_Config) ->
ok.
@@ -129,18 +128,21 @@ init_per_testcase(count_children_memory, Config) ->
try erlang:memory() of
_ ->
erts_debug:set_internal_state(available_internal_state, true),
- Config
+ Dog = ?t:timetrap(?TIMEOUT),
+ [{watchdog,Dog}|Config]
catch error:notsup ->
{skip, "+Meamin used during test; erlang:memory/1 not available"}
end;
init_per_testcase(_Case, Config) ->
- erlang:display(_Case),
- Config.
+ Dog = ?t:timetrap(?TIMEOUT),
+ [{watchdog,Dog}|Config].
-end_per_testcase(count_children_memory, _Config) ->
+end_per_testcase(count_children_memory, Config) ->
catch erts_debug:set_internal_state(available_internal_state, false),
+ ?t:timetrap_cancel(?config(watchdog,Config)),
ok;
-end_per_testcase(_Case, _Config) ->
+end_per_testcase(_Case, Config) ->
+ ?t:timetrap_cancel(?config(watchdog,Config)),
ok.
start_link(InitResult) ->
@@ -1455,6 +1457,102 @@ gen_server9212() ->
%%-------------------------------------------------------------------------
+%% Test that child and supervisor can be shutdown while hanging in restart loop.
+%% See OTP-9549.
+hanging_restart_loop(Config) when is_list(Config) ->
+ process_flag(trap_exit, true),
+ {ok, Pid} = start_link({ok, {{one_for_one, 8, 10}, []}}),
+ Child1 = {child1, {supervisor_deadlock, start_child, []},
+ permanent, brutal_kill, worker, []},
+
+ %% Ets table with state read by supervisor_deadlock.erl
+ ets:new(supervisor_deadlock,[set,named_table,public]),
+ ets:insert(supervisor_deadlock,{fail_start,false}),
+
+ {ok, CPid1} = supervisor:start_child(sup_test, Child1),
+ link(CPid1),
+
+ ets:insert(supervisor_deadlock,{fail_start,true}),
+ supervisor_deadlock:restart_child(),
+ timer:sleep(2000), % allow restart to happen before proceeding
+
+ {error, already_present} = supervisor:start_child(sup_test, Child1),
+ {error, restarting} = supervisor:restart_child(sup_test, child1),
+ {error, restarting} = supervisor:delete_child(sup_test, child1),
+ [{child1,restarting,worker,[]}] = supervisor:which_children(sup_test),
+ [1,0,0,1] = get_child_counts(sup_test),
+
+ ok = supervisor:terminate_child(sup_test, child1),
+ check_exit_reason(CPid1, error),
+ [{child1,undefined,worker,[]}] = supervisor:which_children(sup_test),
+
+ ets:insert(supervisor_deadlock,{fail_start,false}),
+ {ok, CPid2} = supervisor:restart_child(sup_test, child1),
+ link(CPid2),
+
+ ets:insert(supervisor_deadlock,{fail_start,true}),
+ supervisor_deadlock:restart_child(),
+ timer:sleep(2000), % allow restart to happen before proceeding
+
+ %% Terminating supervisor.
+ %% OTP-9549 fixes so this does not give a timetrap timeout -
+ %% i.e. that supervisor does not hang in restart loop.
+ terminate(Pid,shutdown),
+
+ %% Check that child died with reason from 'restart' request above
+ check_exit_reason(CPid2, error),
+ undefined = whereis(sup_test),
+ ok.
+
+%%-------------------------------------------------------------------------
+%% Test that child and supervisor can be shutdown while hanging in
+%% restart loop, simple_one_for_one.
+%% See OTP-9549.
+hanging_restart_loop_simple(Config) when is_list(Config) ->
+ process_flag(trap_exit, true),
+ Child1 = {child1, {supervisor_deadlock, start_child, []},
+ permanent, brutal_kill, worker, []},
+ {ok, Pid} = start_link({ok, {{simple_one_for_one, 8, 10}, [Child1]}}),
+
+ %% Ets table with state read by supervisor_deadlock.erl
+ ets:new(supervisor_deadlock,[set,named_table,public]),
+ ets:insert(supervisor_deadlock,{fail_start,false}),
+
+ {ok, CPid1} = supervisor:start_child(sup_test, []),
+ link(CPid1),
+
+ ets:insert(supervisor_deadlock,{fail_start,true}),
+ supervisor_deadlock:restart_child(),
+ timer:sleep(2000), % allow restart to happen before proceeding
+
+ {error, simple_one_for_one} = supervisor:restart_child(sup_test, child1),
+ {error, simple_one_for_one} = supervisor:delete_child(sup_test, child1),
+ [{undefined,restarting,worker,[]}] = supervisor:which_children(sup_test),
+ [1,0,0,1] = get_child_counts(sup_test),
+
+ ok = supervisor:terminate_child(sup_test, CPid1),
+ check_exit_reason(CPid1, error),
+ [] = supervisor:which_children(sup_test),
+
+ ets:insert(supervisor_deadlock,{fail_start,false}),
+ {ok, CPid2} = supervisor:start_child(sup_test, []),
+ link(CPid2),
+
+ ets:insert(supervisor_deadlock,{fail_start,true}),
+ supervisor_deadlock:restart_child(),
+ timer:sleep(2000), % allow restart to happen before proceeding
+
+ %% Terminating supervisor.
+ %% OTP-9549 fixes so this does not give a timetrap timeout -
+ %% i.e. that supervisor does not hang in restart loop.
+ terminate(Pid,shutdown),
+
+ %% Check that child died with reason from 'restart' request above
+ check_exit_reason(CPid2, error),
+ undefined = whereis(sup_test),
+ ok.
+
+%%-------------------------------------------------------------------------
terminate(Pid, Reason) when Reason =/= supervisor ->
terminate(dummy, Pid, dummy, Reason).
diff --git a/lib/stdlib/test/supervisor_deadlock.erl b/lib/stdlib/test/supervisor_deadlock.erl
new file mode 100644
index 0000000000..288547a972
--- /dev/null
+++ b/lib/stdlib/test/supervisor_deadlock.erl
@@ -0,0 +1,45 @@
+-module(supervisor_deadlock).
+-compile(export_all).
+
+
+%%%-----------------------------------------------------------------
+%%% gen_server callbacks
+init([child]) ->
+ case ets:lookup(supervisor_deadlock,fail_start) of
+ [{fail_start, false}] ->
+ %% we must not fail on the first init, otherwise supervisor
+ %% terminates immediately
+ {ok, []};
+ [{fail_start, true}] ->
+ %% Restart frequency is MaxR=8, MaxT=10, so this will
+ %% ensure that restart intensity is not reached -> restart
+ %% loop
+ timer:sleep(2000), % NOTE: this could be a gen_server call timeout
+
+ {stop, error}
+ end.
+
+handle_call(_Req, _From, State) ->
+ {reply, ok, State}.
+
+%% Force a restart
+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_child() ->
+ gen_server:start_link({local, ?MODULE}, ?MODULE, [child], []).
+
+restart_child() ->
+ gen_server:cast(supervisor_deadlock, restart).
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-16 04:55:28 +0000