diff options
| -rw-r--r-- | lib/stdlib/doc/src/supervisor.xml | 13 | ||||
| -rw-r--r-- | lib/stdlib/src/supervisor.erl | 12 | ||||
| -rw-r--r-- | lib/stdlib/test/supervisor_SUITE.erl | 65 |
3 files changed, 72 insertions, 18 deletions
diff --git a/lib/stdlib/doc/src/supervisor.xml b/lib/stdlib/doc/src/supervisor.xml index cddb55e5c5..33a7f5bb6a 100644 --- a/lib/stdlib/doc/src/supervisor.xml +++ b/lib/stdlib/doc/src/supervisor.xml @@ -127,25 +127,18 @@ child_spec() = {Id,StartFunc,Restart,Shutdown,Type,Modules} <p><c>StartFunc</c> defines the function call used to start the child process. It should be a module-function-arguments tuple <c>{M,F,A}</c> used as <c>apply(M,F,A)</c>.</p> - <p> <br></br> -</p> <p>The start function <em>must create and link to</em> the child process, and should return <c>{ok,Child}</c> or <c>{ok,Child,Info}</c> where <c>Child</c> is the pid of the child process and <c>Info</c> an arbitrary term which is ignored by the supervisor.</p> - <p> <br></br> -</p> <p>The start function can also return <c>ignore</c> if the child process for some reason cannot be started, in which case - the child specification will be kept by the supervisor but - the non-existing child process will be ignored.</p> - <p> <br></br> -</p> + the child specification will be kept by the supervisor + (unless it is a temporary child) but the non-existing child + process will be ignored.</p> <p>If something goes wrong, the function may also return an error tuple <c>{error,Error}</c>.</p> - <p> <br></br> -</p> <p>Note that the <c>start_link</c> functions of the different behaviour modules fulfill the above requirements.</p> </item> diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl index 42ea42f42e..ac5b078c29 100644 --- a/lib/stdlib/src/supervisor.erl +++ b/lib/stdlib/src/supervisor.erl @@ -270,6 +270,8 @@ start_children(Children, SupName) -> start_children(Children, [], SupName). start_children([Child|Chs], NChildren, SupName) -> case do_start_child(SupName, Child) of + {ok, undefined} when Child#child.restart_type =:= temporary -> + start_children(Chs, NChildren, SupName); {ok, Pid} -> start_children(Chs, [Child#child{pid = Pid}|NChildren], SupName); {ok, Pid, _Extra} -> @@ -325,6 +327,8 @@ handle_call({start_child, EArgs}, _From, State) when ?is_simple(State) -> #child{mfargs = {M, F, A}} = Child, Args = A ++ EArgs, case do_start_child_i(M, F, Args) of + {ok, undefined} when Child#child.restart_type =:= temporary -> + {reply, {ok, undefined}, State}; {ok, Pid} -> NState = save_dynamic_child(Child#child.restart_type, Pid, Args, State), {reply, {ok, Pid}, NState}; @@ -611,12 +615,12 @@ handle_start_child(Child, State) -> case get_child(Child#child.name, State) of false -> case do_start_child(State#state.name, Child) of + {ok, undefined} when Child#child.restart_type =:= temporary -> + {{ok, undefined}, State}; {ok, Pid} -> - {{ok, Pid}, - save_child(Child#child{pid = Pid}, State)}; + {{ok, Pid}, save_child(Child#child{pid = Pid}, State)}; {ok, Pid, Extra} -> - {{ok, Pid, Extra}, - save_child(Child#child{pid = Pid}, State)}; + {{ok, Pid, Extra}, save_child(Child#child{pid = Pid}, State)}; {error, What} -> {{error, {What, Child}}, State} end; diff --git a/lib/stdlib/test/supervisor_SUITE.erl b/lib/stdlib/test/supervisor_SUITE.erl index fa6faa66f2..71b76c093f 100644 --- a/lib/stdlib/test/supervisor_SUITE.erl +++ b/lib/stdlib/test/supervisor_SUITE.erl @@ -34,8 +34,10 @@ %% API tests -export([ sup_start_normal/1, sup_start_ignore_init/1, - sup_start_ignore_child/1, sup_start_error_return/1, - sup_start_fail/1, sup_stop_infinity/1, + sup_start_ignore_child/1, sup_start_ignore_temporary_child/1, + sup_start_ignore_temporary_child_start_child/1, + sup_start_ignore_temporary_child_start_child_simple/1, + sup_start_error_return/1, sup_start_fail/1, sup_stop_infinity/1, sup_stop_timeout/1, sup_stop_brutal_kill/1, child_adm/1, child_adm_simple/1, child_specs/1, extra_return/1]). @@ -85,8 +87,10 @@ all() -> groups() -> [{sup_start, [], [sup_start_normal, sup_start_ignore_init, - sup_start_ignore_child, sup_start_error_return, - sup_start_fail]}, + sup_start_ignore_child, sup_start_ignore_temporary_child, + sup_start_ignore_temporary_child_start_child, + sup_start_ignore_temporary_child_start_child_simple, + sup_start_error_return, sup_start_fail]}, {sup_stop, [], [sup_stop_infinity, sup_stop_timeout, sup_stop_brutal_kill]}, @@ -191,6 +195,59 @@ sup_start_ignore_child(Config) when is_list(Config) -> [2,1,0,2] = get_child_counts(sup_test). %%------------------------------------------------------------------------- +%% Tests what happens if child's init-callback returns ignore for a +%% temporary child when ChildSpec is returned directly from supervisor +%% init callback. +%% Child spec shall NOT be saved!!! +sup_start_ignore_temporary_child(Config) when is_list(Config) -> + process_flag(trap_exit, true), + Child1 = {child1, {supervisor_1, start_child, [ignore]}, + temporary, 1000, worker, []}, + Child2 = {child2, {supervisor_1, start_child, []}, temporary, + 1000, worker, []}, + {ok, _Pid} = start_link({ok, {{one_for_one, 2, 3600}, [Child1,Child2]}}), + + [{child2, CPid2, worker, []}] = supervisor:which_children(sup_test), + true = is_pid(CPid2), + [1,1,0,1] = get_child_counts(sup_test). + +%%------------------------------------------------------------------------- +%% Tests what happens if child's init-callback returns ignore for a +%% temporary child when child is started with start_child/2. +%% Child spec shall NOT be saved!!! +sup_start_ignore_temporary_child_start_child(Config) when is_list(Config) -> + process_flag(trap_exit, true), + {ok, _Pid} = start_link({ok, {{one_for_one, 2, 3600}, []}}), + Child1 = {child1, {supervisor_1, start_child, [ignore]}, + temporary, 1000, worker, []}, + Child2 = {child2, {supervisor_1, start_child, []}, temporary, + 1000, worker, []}, + + {ok, undefined} = supervisor:start_child(sup_test, Child1), + {ok, CPid2} = supervisor:start_child(sup_test, Child2), + + [{child2, CPid2, worker, []}] = supervisor:which_children(sup_test), + [1,1,0,1] = get_child_counts(sup_test). + +%%------------------------------------------------------------------------- +%% Tests what happens if child's init-callback returns ignore for a +%% temporary child when child is started with start_child/2, and the +%% supervisor is simple_one_for_one. +%% Child spec shall NOT be saved!!! +sup_start_ignore_temporary_child_start_child_simple(Config) + when is_list(Config) -> + process_flag(trap_exit, true), + Child1 = {child1, {supervisor_1, start_child, [ignore]}, + temporary, 1000, worker, []}, + {ok, _Pid} = start_link({ok, {{simple_one_for_one, 2, 3600}, [Child1]}}), + + {ok, undefined} = supervisor:start_child(sup_test, []), + {ok, CPid2} = supervisor:start_child(sup_test, []), + + [{undefined, CPid2, worker, []}] = supervisor:which_children(sup_test), + [1,1,0,1] = get_child_counts(sup_test). + +%%------------------------------------------------------------------------- %% Tests what happens if init-callback returns a invalid value. sup_start_error_return(Config) when is_list(Config) -> process_flag(trap_exit, true), |