diff options
| -rw-r--r-- | lib/dialyzer/test/behaviour_SUITE_data/results/gen_event_incorrect_return | 2 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_event.xml | 17 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_event.erl | 3 |
3 files changed, 13 insertions, 9 deletions
diff --git a/lib/dialyzer/test/behaviour_SUITE_data/results/gen_event_incorrect_return b/lib/dialyzer/test/behaviour_SUITE_data/results/gen_event_incorrect_return index 2afb5db133..e646eea383 100644 --- a/lib/dialyzer/test/behaviour_SUITE_data/results/gen_event_incorrect_return +++ b/lib/dialyzer/test/behaviour_SUITE_data/results/gen_event_incorrect_return @@ -1,2 +1,2 @@ -gen_event_incorrect_return.erl:16: The inferred return type of init/1 ('error') has nothing in common with {'ok',_} | {'ok',_,'hibernate'}, which is the expected return type for the callback of gen_event behaviour +gen_event_incorrect_return.erl:16: The inferred return type of init/1 ('error') has nothing in common with {'error',_} | {'ok',_} | {'ok',_,'hibernate'}, which is the expected return type for the callback of gen_event behaviour diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml index 24bcb419fe..79a0c8ad89 100644 --- a/lib/stdlib/doc/src/gen_event.xml +++ b/lib/stdlib/doc/src/gen_event.xml @@ -195,12 +195,13 @@ gen_event:stop -----> Module:terminate/2 handlers using the same callback module.</p> <p><c>Args</c> is an arbitrary term which is passed as the argument to <c>Module:init/1</c>.</p> - <p>If <c>Module:init/1</c> returns a correct value, the event - manager adds the event handler and this function returns + <p>If <c>Module:init/1</c> returns a correct value indicating + successful completion, the event manager adds the event + handler and this function returns <c>ok</c>. If <c>Module:init/1</c> fails with <c>Reason</c> or - returns an unexpected value <c>Term</c>, the event handler is + returns <c>{error,Reason}</c>, the event handler is ignored and this function returns <c>{'EXIT',Reason}</c> or - <c>Term</c>, respectively.</p> + <c>{error,Reason}</c>, respectively.</p> </desc> </func> <func> @@ -448,12 +449,13 @@ gen_event:stop -----> Module:terminate/2 </section> <funcs> <func> - <name>Module:init(InitArgs) -> {ok,State} | {ok,State,hibernate}</name> + <name>Module:init(InitArgs) -> {ok,State} | {ok,State,hibernate} | {error,Reason}</name> <fsummary>Initialize an event handler.</fsummary> <type> <v>InitArgs = Args | {Args,Term}</v> <v> Args = Term = term()</v> <v>State = term()</v> + <v>Reason = term()</v> </type> <desc> <p>Whenever a new event handler is added to an event manager, @@ -470,8 +472,9 @@ gen_event:stop -----> Module:terminate/2 the argument provided in the function call/return tuple and <c>Term</c> is the result of terminating the old event handler, see <c>gen_event:swap_handler/3</c>.</p> - <p>The function should return <c>{ok,State}</c> or <c>{ok,State, hibernate}</c> - where <c>State</c> is the initial internal state of the event handler.</p> + <p>If successful, the function should return <c>{ok,State}</c> + or <c>{ok,State,hibernate}</c> where <c>State</c> is the + initial internal state of the event handler.</p> <p>If <c>{ok,State,hibernate}</c> is returned, the event manager will go into hibernation (by calling <seealso marker="proc_lib#hibernate/3">proc_lib:hibernate/3</seealso>), diff --git a/lib/stdlib/src/gen_event.erl b/lib/stdlib/src/gen_event.erl index 9879b76391..3317b30e5c 100644 --- a/lib/stdlib/src/gen_event.erl +++ b/lib/stdlib/src/gen_event.erl @@ -70,7 +70,8 @@ -callback init(InitArgs :: term()) -> {ok, State :: term()} | - {ok, State :: term(), hibernate}. + {ok, State :: term(), hibernate} | + {error, Reason :: term()}. -callback handle_event(Event :: term(), State :: term()) -> {ok, NewState :: term()} | {ok, NewState :: term(), hibernate} | |