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Diffstat (limited to 'lib/kernel/src/logger_handler_watcher.erl')
-rw-r--r-- | lib/kernel/src/logger_handler_watcher.erl | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/lib/kernel/src/logger_handler_watcher.erl b/lib/kernel/src/logger_handler_watcher.erl new file mode 100644 index 0000000000..b75c74c643 --- /dev/null +++ b/lib/kernel/src/logger_handler_watcher.erl @@ -0,0 +1,113 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2018. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% +-module(logger_handler_watcher). + +-behaviour(gen_server). + +%% API +-export([start_link/0]). +-export([register_handler/2]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2]). + +-define(SERVER, ?MODULE). + +-record(state, {handlers}). + +%%%=================================================================== +%%% API +%%%=================================================================== + +-spec start_link() -> {ok, Pid :: pid()} | + {error, Error :: {already_started, pid()}} | + {error, Error :: term()} | + ignore. +start_link() -> + gen_server:start_link({local, ?SERVER}, ?MODULE, [], []). + +-spec register_handler(Id::logger:handler_id(),Pid::pid()) -> ok. +register_handler(Id,Pid) -> + gen_server:call(?SERVER,{register,Id,Pid}). + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +-spec init(Args :: term()) -> {ok, State :: term()} | + {ok, State :: term(), Timeout :: timeout()} | + {ok, State :: term(), hibernate} | + {stop, Reason :: term()} | + ignore. +init([]) -> + process_flag(trap_exit, true), + {ok, #state{handlers=[]}}. + +-spec handle_call(Request :: term(), From :: {pid(), term()}, State :: term()) -> + {reply, Reply :: term(), NewState :: term()} | + {reply, Reply :: term(), NewState :: term(), Timeout :: timeout()} | + {reply, Reply :: term(), NewState :: term(), hibernate} | + {noreply, NewState :: term()} | + {noreply, NewState :: term(), Timeout :: timeout()} | + {noreply, NewState :: term(), hibernate} | + {stop, Reason :: term(), Reply :: term(), NewState :: term()} | + {stop, Reason :: term(), NewState :: term()}. +handle_call({register,Id,Pid}, _From, #state{handlers=Hs}=State) -> + Ref = erlang:monitor(process,Pid), + Hs1 = lists:keystore(Id,1,Hs,{Id,Ref}), + {reply, ok, State#state{handlers=Hs1}}. + +-spec handle_cast(Request :: term(), State :: term()) -> + {noreply, NewState :: term()} | + {noreply, NewState :: term(), Timeout :: timeout()} | + {noreply, NewState :: term(), hibernate} | + {stop, Reason :: term(), NewState :: term()}. +handle_cast(_Request, State) -> + {noreply, State}. + +-spec handle_info(Info :: timeout() | term(), State :: term()) -> + {noreply, NewState :: term()} | + {noreply, NewState :: term(), Timeout :: timeout()} | + {noreply, NewState :: term(), hibernate} | + {stop, Reason :: normal | term(), NewState :: term()}. +handle_info({'DOWN',Ref,process,_,shutdown}, #state{handlers=Hs}=State) -> + case lists:keytake(Ref,2,Hs) of + {value,{Id,Ref},Hs1} -> + %% Probably terminated by supervisor. Remove the handler to avoid + %% error printouts due to failing handler. + _ = case logger:get_handler_config(Id) of + {ok,_} -> + logger:remove_handler(Id); + _ -> + ok + end, + {noreply,State#state{handlers=Hs1}}; + false -> + {noreply, State} + end; +handle_info({'DOWN',Ref,process,_,_OtherReason}, #state{handlers=Hs}=State) -> + {noreply,State#state{handlers=lists:keydelete(Ref,2,Hs)}}; +handle_info(_Other,State) -> + {noreply,State}. + +-spec terminate(Reason :: normal | shutdown | {shutdown, term()} | term(), + State :: term()) -> any(). +terminate(_Reason, _State) -> + ok. |