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Diffstat (limited to 'lib/kernel/src/logger_std_h.erl')
| -rw-r--r-- | lib/kernel/src/logger_std_h.erl | 826 |
1 files changed, 826 insertions, 0 deletions
diff --git a/lib/kernel/src/logger_std_h.erl b/lib/kernel/src/logger_std_h.erl new file mode 100644 index 0000000000..480fafd6d8 --- /dev/null +++ b/lib/kernel/src/logger_std_h.erl @@ -0,0 +1,826 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2017-2018. 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_std_h). + +-behaviour(gen_server). + +-include("logger.hrl"). +-include("logger_internal.hrl"). +-include("logger_h_common.hrl"). + +-include_lib("kernel/include/file.hrl"). + +%% API +-export([start_link/3, info/1, filesync/1, reset/1]). + +%% gen_server and proc_lib callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +%% logger callbacks +-export([log/2, adding_handler/1, removing_handler/1, changing_config/2]). + +%% handler internal +-export([log_handler_info/4]). + +%%%=================================================================== +%%% API +%%%=================================================================== + +%%%----------------------------------------------------------------- +%%% Start a standard handler process and link to caller. +%%% This function is called by the kernel supervisor when this +%%% handler process gets added +-spec start_link(Name, Config, HandlerState) -> {ok,Pid} | {error,Reason} when + Name :: atom(), + Config :: logger:handler_config(), + HandlerState :: map(), + Pid :: pid(), + Reason :: term(). + +start_link(Name, Config, HandlerState) -> + proc_lib:start_link(?MODULE,init,[[Name,Config,HandlerState]]). + +%%%----------------------------------------------------------------- +%%% +-spec filesync(Name) -> ok | {error,Reason} when + Name :: atom(), + Reason :: handler_busy | {badarg,term()}. + +filesync(Name) when is_atom(Name) -> + try + gen_server:call(?name_to_reg_name(?MODULE,Name), + filesync, ?DEFAULT_CALL_TIMEOUT) + catch + _:{timeout,_} -> {error,handler_busy} + end; +filesync(Name) -> + {error,{badarg,{filesync,[Name]}}}. + +%%%----------------------------------------------------------------- +%%% +-spec info(Name) -> Info | {error,Reason} when + Name :: atom(), + Info :: term(), + Reason :: handler_busy | {badarg,term()}. + +info(Name) when is_atom(Name) -> + try + gen_server:call(?name_to_reg_name(?MODULE,Name), + info, ?DEFAULT_CALL_TIMEOUT) + catch + _:{timeout,_} -> {error,handler_busy} + end; +info(Name) -> + {error,{badarg,{info,[Name]}}}. + +%%%----------------------------------------------------------------- +%%% +-spec reset(Name) -> ok | {error,Reason} when + Name :: atom(), + Reason :: handler_busy | {badarg,term()}. + +reset(Name) when is_atom(Name) -> + try + gen_server:call(?name_to_reg_name(?MODULE,Name), + reset, ?DEFAULT_CALL_TIMEOUT) + catch + _:{timeout,_} -> {error,handler_busy} + end; +reset(Name) -> + {error,{badarg,{reset,[Name]}}}. + + +%%%=================================================================== +%%% logger callbacks +%%%=================================================================== + +%%%----------------------------------------------------------------- +%%% Handler being added +adding_handler(#{id:=Name}=Config) -> + case check_config(adding, Config) of + {ok, Config1} -> + %% create initial handler state by merging defaults with config + HConfig = maps:get(config, Config1, #{}), + HState = maps:merge(get_init_state(), HConfig), + case logger_h_common:overload_levels_ok(HState) of + true -> + start(Name, Config1, HState); + false -> + #{sync_mode_qlen := SMQL, + drop_mode_qlen := DMQL, + flush_qlen := FQL} = HState, + {error,{invalid_levels,{SMQL,DMQL,FQL}}} + end; + Error -> + Error + end. + +%%%----------------------------------------------------------------- +%%% Updating handler config +changing_config(OldConfig=#{id:=Name, config:=OldHConfig}, + NewConfig=#{id:=Name}) -> + #{type:=Type, handler_pid:=HPid, mode_tab:=ModeTab} = OldHConfig, + NewHConfig = maps:get(config, NewConfig, #{}), + case maps:get(type, NewHConfig, Type) of + Type -> + NewHConfig1 = NewHConfig#{type=>Type, + handler_pid=>HPid, + mode_tab=>ModeTab}, + changing_config1(HPid, OldConfig, + NewConfig#{config=>NewHConfig1}); + _ -> + {error,{illegal_config_change,OldConfig,NewConfig}} + end; +changing_config(OldConfig, NewConfig) -> + {error,{illegal_config_change,OldConfig,NewConfig}}. + +changing_config1(HPid, OldConfig, NewConfig) -> + case check_config(changing, NewConfig) of + Result = {ok,NewConfig1} -> + try gen_server:call(HPid, {change_config,OldConfig,NewConfig1}, + ?DEFAULT_CALL_TIMEOUT) of + ok -> Result; + HError -> HError + catch + _:{timeout,_} -> {error,handler_busy} + end; + Error -> + Error + end. + +check_config(adding, Config) -> + %% Merge in defaults on handler level + HConfig0 = maps:get(config, Config, #{}), + HConfig = maps:merge(#{type => standard_io}, + HConfig0), + case check_h_config(maps:to_list(HConfig)) of + ok -> + {ok,Config#{config=>HConfig}}; + Error -> + Error + end; +check_config(changing, Config) -> + HConfig = maps:get(config, Config, #{}), + case check_h_config(maps:to_list(HConfig)) of + ok -> {ok,Config}; + Error -> Error + end. + +check_h_config([{type,Type} | Config]) when Type == standard_io; + Type == standard_error -> + check_h_config(Config); +check_h_config([{type,{file,File}} | Config]) when is_list(File) -> + check_h_config(Config); +check_h_config([{type,{file,File,Modes}} | Config]) when is_list(File), + is_list(Modes) -> + check_h_config(Config); +check_h_config([Other | Config]) -> + case logger_h_common:check_common_config(Other) of + valid -> + check_h_config(Config); + invalid -> + {error,{invalid_config,?MODULE,Other}} + end; +check_h_config([]) -> + ok. + + +%%%----------------------------------------------------------------- +%%% Handler being removed +removing_handler(#{id:=Name}) -> + stop(Name). + +%%%----------------------------------------------------------------- +%%% Log a string or report +-spec log(LogEvent, Config) -> ok | dropped when + LogEvent :: logger:log_event(), + Config :: logger:handler_config(). + +log(LogEvent, Config = #{id := Name, + config := #{handler_pid := HPid, + mode_tab := ModeTab}}) -> + %% if the handler has crashed, we must drop this event + %% and hope the handler restarts so we can try again + true = is_process_alive(HPid), + Bin = logger_h_common:log_to_binary(LogEvent, Config), + logger_h_common:call_cast_or_drop(Name, HPid, ModeTab, Bin). + +%%%=================================================================== +%%% gen_server callbacks +%%%=================================================================== + +init([Name, Config = #{config := HConfig}, + State0 = #{type := Type, file_ctrl_sync_int := FileCtrlSyncInt}]) -> + RegName = ?name_to_reg_name(?MODULE,Name), + register(RegName, self()), + process_flag(trap_exit, true), + process_flag(message_queue_data, off_heap), + + ?init_test_hooks(), + ?start_observation(Name), + + case do_init(Name, Type) of + {ok,InitState} -> + try ets:new(Name, [public]) of + ModeTab -> + ?set_mode(ModeTab, async), + State = maps:merge(State0, InitState), + T0 = ?timestamp(), + State1 = + ?merge_with_stats(State#{ + mode_tab => ModeTab, + mode => async, + file_ctrl_sync => FileCtrlSyncInt, + last_qlen => 0, + last_log_ts => T0, + last_op => sync, + burst_win_ts => T0, + burst_msg_count => 0}), + Config1 = + Config#{config => HConfig#{handler_pid => self(), + mode_tab => ModeTab}}, + proc_lib:init_ack({ok,self(),Config1}), + gen_server:cast(self(), repeated_filesync), + enter_loop(Config1, State1) + catch + _:Error -> + unregister(RegName), + logger_h_common:error_notify({init_handler,Name,Error}), + proc_lib:init_ack(Error) + end; + Error -> + unregister(RegName), + logger_h_common:error_notify({init_handler,Name,Error}), + proc_lib:init_ack(Error) + end. + +do_init(Name, Type) -> + case open_log_file(Name, Type) of + {ok,FileCtrlPid} -> + case logger_h_common:unset_restart_flag(Name, ?MODULE) of + true -> + %% inform about restart + gen_server:cast(self(), {log_handler_info, + "Handler ~p restarted", + [Name]}); + false -> + %% initial start + ok + end, + {ok,#{id=>Name,type=>Type,file_ctrl_pid=>FileCtrlPid}}; + Error -> + Error + end. + +enter_loop(_Config,State) -> + gen_server:enter_loop(?MODULE,[],State). + +%% This is the synchronous log event. +handle_call({log, Bin}, _From, State) -> + {Result,State1} = do_log(Bin, call, State), + %% Result == ok | dropped + {reply,Result, State1}; + +handle_call(filesync, _From, State = #{type := Type, + file_ctrl_pid := FileCtrlPid}) -> + if is_atom(Type) -> + {reply, ok, State}; + true -> + {reply, file_ctrl_filesync_sync(FileCtrlPid), State#{last_op=>sync}} + end; + +handle_call({change_config,_OldConfig,NewConfig}, _From, + State = #{filesync_repeat_interval := FSyncInt0}) -> + HConfig = maps:get(config, NewConfig, #{}), + State1 = maps:merge(State, HConfig), + case logger_h_common:overload_levels_ok(State1) of + true -> + _ = + case maps:get(filesync_repeat_interval, HConfig, undefined) of + undefined -> + ok; + no_repeat -> + _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, + State, + undefined)); + FSyncInt0 -> + ok; + _FSyncInt1 -> + _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, + State, + undefined)), + gen_server:cast(self(), repeated_filesync) + end, + {reply, ok, State1}; + false -> + #{sync_mode_qlen := SMQL, + drop_mode_qlen := DMQL, + flush_qlen := FQL} = State1, + {reply, {error,{invalid_levels,{SMQL,DMQL,FQL}}}, State} + end; + +handle_call(info, _From, State) -> + {reply, State, State}; + +handle_call(reset, _From, State) -> + State1 = ?merge_with_stats(State), + {reply, ok, State1#{last_qlen => 0, + last_log_ts => ?timestamp()}}; + +handle_call(stop, _From, State) -> + {stop, {shutdown,stopped}, ok, State}. + +%% This is the asynchronous log event. +handle_cast({log, Bin}, State) -> + {_,State1} = do_log(Bin, cast, State), + {noreply, State1}; + +handle_cast({log_handler_info, Format, Args}, State = #{id:=Name}) -> + log_handler_info(Name, Format, Args, State), + {noreply, State}; + +%% If FILESYNC_REPEAT_INTERVAL is set to a millisec value, this +%% clause gets called repeatedly by the handler. In order to +%% guarantee that a filesync *always* happens after the last log +%% event, the repeat operation must be active! +handle_cast(repeated_filesync, + State = #{type := Type, + file_ctrl_pid := FileCtrlPid, + filesync_repeat_interval := FSyncInt, + last_op := LastOp}) -> + State1 = + if not is_atom(Type), is_integer(FSyncInt) -> + %% only do filesync if something has been + %% written since last time we checked + if LastOp == sync -> + ok; + true -> + file_ctrl_filesync_async(FileCtrlPid) + end, + {ok,TRef} = + timer:apply_after(FSyncInt, gen_server,cast, + [self(),repeated_filesync]), + State#{rep_sync_tref => TRef, last_op => sync}; + true -> + State + end, + {noreply,State1}. + +handle_info({'EXIT',Pid,Why}, State = #{id := Name, type := FileInfo}) -> + case maps:get(file_ctrl_pid, State, undefined) of + Pid -> + %% file error, terminate handler + logger_h_common:handler_exit(Name, + {error,{write_failed,FileInfo,Why}}); + _Other -> + %% ignore EXIT + ok + end, + {noreply, State}; + +handle_info(_Info, State) -> + {noreply, State}. + +terminate(Reason, State = #{id:=Name, file_ctrl_pid:=FWPid, + type:=_FileInfo}) -> + _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, State, + undefined)), + case is_process_alive(FWPid) of + true -> + unlink(FWPid), + _ = file_ctrl_stop(FWPid), + MRef = erlang:monitor(process, FWPid), + receive + {'DOWN',MRef,_,_,_} -> + ok + after + ?DEFAULT_CALL_TIMEOUT -> + exit(FWPid, kill) + end; + false -> + ok + end, + unregister(?name_to_reg_name(?MODULE, Name)), + logger_h_common:stop_or_restart(Name, Reason, State). + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%%%=================================================================== +%%% Internal functions +%%%=================================================================== + +%%%----------------------------------------------------------------- +%%% +get_init_state() -> + #{sync_mode_qlen => ?SYNC_MODE_QLEN, + drop_mode_qlen => ?DROP_MODE_QLEN, + flush_qlen => ?FLUSH_QLEN, + burst_limit_enable => ?BURST_LIMIT_ENABLE, + burst_limit_max_count => ?BURST_LIMIT_MAX_COUNT, + burst_limit_window_time => ?BURST_LIMIT_WINDOW_TIME, + overload_kill_enable => ?OVERLOAD_KILL_ENABLE, + overload_kill_qlen => ?OVERLOAD_KILL_QLEN, + overload_kill_mem_size => ?OVERLOAD_KILL_MEM_SIZE, + overload_kill_restart_after => ?OVERLOAD_KILL_RESTART_AFTER, + file_ctrl_sync_int => ?CONTROLLER_SYNC_INTERVAL, + filesync_ok_qlen => ?FILESYNC_OK_QLEN, + filesync_repeat_interval => ?FILESYNC_REPEAT_INTERVAL}. + +%%%----------------------------------------------------------------- +%%% Add a standard handler to the logger. +%%% This starts a dedicated handler process which should always +%%% exist if the handler is registered with logger (and should not +%%% exist if the handler is not registered). +%%% +%%% Handler specific config should be provided with a sub map associated +%%% with a key named 'config', e.g: +%%% +%%% Config = #{config => #{sync_mode_qlen => 50} +%%% +%%% The standard handler process is linked to logger_sup, which is +%%% part of the kernel application's supervision tree. +start(Name, Config, HandlerState) -> + LoggerStdH = + #{id => Name, + start => {?MODULE, start_link, [Name,Config,HandlerState]}, + restart => temporary, + shutdown => 2000, + type => worker, + modules => [?MODULE]}, + case supervisor:start_child(logger_sup, LoggerStdH) of + {ok,_Pid,Config1} -> + {ok,Config1}; + Error -> + Error + end. + +%%%----------------------------------------------------------------- +%%% Stop and remove the handler. +stop(Name) -> + case whereis(?name_to_reg_name(?MODULE,Name)) of + undefined -> + ok; + Pid -> + %% We don't want to do supervisor:terminate_child here + %% since we need to distinguish this explicit stop from a + %% system termination in order to avoid circular attempts + %% at removing the handler (implying deadlocks and + %% timeouts). + _ = gen_server:call(Pid, stop), + _ = supervisor:delete_child(logger_sup, Name), + ok + end. + +%%%----------------------------------------------------------------- +%%% Logging and overload control. +-define(update_file_ctrl_sync(C, Interval), + if C == 0 -> Interval; + true -> C-1 end). + +%% check for overload between every event (and set Mode to async, +%% sync or drop accordingly), but never flush the whole mailbox +%% before LogWindowSize events have been handled +do_log(Bin, CallOrCast, State = #{id:=Name, mode:=Mode0}) -> + T1 = ?timestamp(), + + %% check if the handler is getting overloaded, or if it's + %% recovering from overload (the check must be done for each + %% event to react quickly to large bursts of events and + %% to ensure that the handler can never end up in drop mode + %% with an empty mailbox, which would stop operation) + {Mode1,QLen,Mem,State1} = logger_h_common:check_load(State), + + if (Mode1 == drop) andalso (Mode0 =/= drop) -> + log_handler_info(Name, "Handler ~p switched to drop mode", + [Name], State); + (Mode0 == drop) andalso ((Mode1 == async) orelse (Mode1 == sync)) -> + log_handler_info(Name, "Handler ~p switched to ~w mode", + [Name,Mode1], State); + true -> + ok + end, + + %% kill the handler if it can't keep up with the load + logger_h_common:kill_if_choked(Name, QLen, Mem, ?MODULE, State), + + if Mode1 == flush -> + flush(Name, QLen, T1, State1); + true -> + write(Name, Mode1, T1, Bin, CallOrCast, State1) + end. + +%% this clause is called by do_log/3 after an overload check +%% has been performed, where QLen > FlushQLen +flush(Name, _QLen0, T1, State=#{last_log_ts := _T0, mode_tab := ModeTab}) -> + %% flush messages in the mailbox (a limited number in + %% order to not cause long delays) + NewFlushed = logger_h_common:flush_log_events(?FLUSH_MAX_N), + + %% write info in log about flushed messages + log_handler_info(Name, "Handler ~p flushed ~w log events", + [Name,NewFlushed], State), + + %% because of the receive loop when flushing messages, the + %% handler will be scheduled out often and the mailbox could + %% grow very large, so we'd better check the queue again here + {_,_QLen1} = process_info(self(), message_queue_len), + ?observe(Name,{max_qlen,_QLen1}), + + %% Add 1 for the current log event + ?observe(Name,{flushed,NewFlushed+1}), + + State1 = ?update_max_time(?diff_time(T1,_T0),State), + {dropped,?update_other(flushed,FLUSHED,NewFlushed, + State1#{mode => ?set_mode(ModeTab,async), + last_qlen => 0, + last_log_ts => T1})}. + +%% this clause is called to write to file +write(_Name, Mode, T1, Bin, _CallOrCast, + State = #{mode_tab := ModeTab, + file_ctrl_pid := FileCtrlPid, + file_ctrl_sync := FileCtrlSync, + last_qlen := LastQLen, + last_log_ts := T0, + file_ctrl_sync_int := FileCtrlSyncInt}) -> + %% check if we need to limit the number of writes + %% during a burst of log events + {DoWrite,BurstWinT,BurstMsgCount} = logger_h_common:limit_burst(State), + + %% only send a synhrounous event to the file controller process + %% every FileCtrlSyncInt time, to give the handler time between + %% file writes so it can keep up with incoming messages + {Result,LastQLen1} = + if DoWrite, FileCtrlSync == 0 -> + ?observe(_Name,{_CallOrCast,1}), + file_write_sync(FileCtrlPid, Bin, false), + {ok,element(2, process_info(self(), message_queue_len))}; + DoWrite -> + ?observe(_Name,{_CallOrCast,1}), + file_write_async(FileCtrlPid, Bin), + {ok,LastQLen}; + not DoWrite -> + ?observe(_Name,{flushed,1}), + {dropped,LastQLen} + end, + + %% Check if the time since the previous log event is long enough - + %% and the queue length small enough - to assume the mailbox has + %% been emptied, and if so, do filesync operation and reset mode to + %% async. Note that this is the best we can do to detect an idle + %% handler without setting a timer after each log call/cast. If the + %% time between two consecutive log events is fast and no new + %% event comes in after the last one, idle state won't be detected! + Time = ?diff_time(T1,T0), + {Mode1,BurstMsgCount1} = + if (LastQLen1 < ?FILESYNC_OK_QLEN) andalso + (Time > ?IDLE_DETECT_TIME_USEC) -> + %% do filesync if necessary + case maps:get(type, State) of + Std when is_atom(Std) -> + ok; + _File -> + file_ctrl_filesync_async(FileCtrlPid) + end, + {?change_mode(ModeTab, Mode, async),0}; + true -> + {Mode,BurstMsgCount} + end, + State1 = + ?update_calls_or_casts(_CallOrCast,1,State), + State2 = + ?update_max_time(Time, + State1#{mode => Mode1, + last_qlen := LastQLen1, + last_log_ts => T1, + last_op => write, + burst_win_ts => BurstWinT, + burst_msg_count => BurstMsgCount1, + file_ctrl_sync => + ?update_file_ctrl_sync(FileCtrlSync, + FileCtrlSyncInt)}), + {Result,State2}. + +open_log_file(HandlerName, FileInfo) -> + case file_ctrl_start(HandlerName, FileInfo) of + OK = {ok,_FileCtrlPid} -> OK; + Error -> Error + end. + +do_open_log_file({file,File}) -> + do_open_log_file({file,File,[raw,append,delayed_write]}); + +do_open_log_file({file,File,[]}) -> + do_open_log_file({file,File,[raw,append,delayed_write]}); + +do_open_log_file({file,File,Modes}) -> + try + case filelib:ensure_dir(File) of + ok -> + file:open(File, Modes); + Error -> + Error + end + catch + _:Reason -> {error,Reason} + end. + +close_log_file(Std) when Std == standard_io; Std == standard_error -> + ok; +close_log_file(Fd) -> + _ = file:datasync(Fd), + _ = file:close(Fd). + + +log_handler_info(Name, Format, Args, #{file_ctrl_pid := FileCtrlPid}) -> + Config = + case logger:get_handler_config(Name) of + {ok,Conf} -> Conf; + _ -> #{formatter=>{?DEFAULT_FORMATTER,?DEFAULT_FORMAT_CONFIG}} + end, + Meta = #{time=>erlang:system_time(microsecond)}, + Bin = logger_h_common:log_to_binary(#{level => notice, + msg => {Format,Args}, + meta => Meta}, Config), + _ = file_write_async(FileCtrlPid, Bin), + ok. + +%%%----------------------------------------------------------------- +%%% File control process + +file_ctrl_start(HandlerName, FileInfo) -> + Starter = self(), + FileCtrlPid = + spawn_link(fun() -> + file_ctrl_init(HandlerName, FileInfo, Starter) + end), + receive + {FileCtrlPid,ok} -> + {ok,FileCtrlPid}; + {FileCtrlPid,Error} -> + Error + after + ?DEFAULT_CALL_TIMEOUT -> + {error,file_ctrl_process_not_started} + end. + +file_ctrl_stop(Pid) -> + Pid ! stop. + +file_write_async(Pid, Bin) -> + Pid ! {log,Bin}, + ok. + +file_write_sync(Pid, Bin, FileSync) -> + case file_ctrl_call(Pid, {log,self(),Bin,FileSync}) of + {error,Reason} -> + {error,{write_failed,Bin,Reason}}; + Result -> + Result + end. + +file_ctrl_filesync_async(Pid) -> + Pid ! filesync, + ok. + +file_ctrl_filesync_sync(Pid) -> + file_ctrl_call(Pid, {filesync,self()}). + +file_ctrl_call(Pid, Msg) -> + MRef = monitor(process, Pid), + Pid ! {Msg,MRef}, + receive + {MRef,Result} -> + demonitor(MRef, [flush]), + Result; + {'DOWN',MRef,_Type,_Object,Reason} -> + {error,Reason} + after + ?DEFAULT_CALL_TIMEOUT -> + {error,{no_response,Pid}} + end. + +file_ctrl_init(HandlerName, FileInfo, Starter) when is_tuple(FileInfo) -> + process_flag(message_queue_data, off_heap), + FileName = element(2, FileInfo), + case do_open_log_file(FileInfo) of + {ok,Fd} -> + Starter ! {self(),ok}, + file_ctrl_loop(Fd, file, FileName, false, ok, ok, HandlerName); + {error,Reason} -> + Starter ! {self(),{error,{open_failed,FileName,Reason}}} + end; +file_ctrl_init(HandlerName, StdDev, Starter) -> + Starter ! {self(),ok}, + file_ctrl_loop(StdDev, standard_io, StdDev, false, ok, ok, HandlerName). + +file_ctrl_loop(Fd, Type, DevName, Synced, + PrevWriteResult, PrevSyncResult, HandlerName) -> + receive + %% asynchronous event + {log,Bin} -> + Result = if Type == file -> + write_to_dev(Fd, Bin, DevName, + PrevWriteResult, HandlerName); + true -> + io:put_chars(Fd, Bin) + end, + file_ctrl_loop(Fd, Type, DevName, false, + Result, PrevSyncResult, HandlerName); + + %% synchronous event + {{log,From,Bin,FileSync},MRef} -> + if Type == file -> + %% check that file hasn't been deleted + CheckFile = + fun() -> {ok,_} = file:read_file_info(DevName) end, + spawn_link(CheckFile), + WResult = write_to_dev(Fd, Bin, DevName, + PrevWriteResult, HandlerName), + {Synced1,SResult} = + if not FileSync -> + {false,PrevSyncResult}; + true -> + case sync_dev(Fd, DevName, + PrevSyncResult, HandlerName) of + ok -> {true,ok}; + Error -> {false,Error} + end + end, + From ! {MRef,ok}, + file_ctrl_loop(Fd, Type, DevName, Synced1, + WResult, SResult, HandlerName); + true -> + _ = io:put_chars(Fd, Bin), + From ! {MRef,ok}, + file_ctrl_loop(Fd, Type, DevName, false, + ok, PrevSyncResult, HandlerName) + end; + + filesync when not Synced -> + Result = sync_dev(Fd, DevName, PrevSyncResult, HandlerName), + file_ctrl_loop(Fd, Type, DevName, true, + PrevWriteResult, Result, HandlerName); + + filesync -> + file_ctrl_loop(Fd, Type, DevName, true, + PrevWriteResult, PrevSyncResult, HandlerName); + + {{filesync,From},MRef} -> + Result = if not Synced -> + sync_dev(Fd, DevName, PrevSyncResult, HandlerName); + true -> + ok + end, + From ! {MRef,ok}, + file_ctrl_loop(Fd, Type, DevName, true, + PrevWriteResult, Result, HandlerName); + + stop -> + _ = close_log_file(Fd), + stopped + end. + +write_to_dev(Fd, Bin, FileName, PrevWriteResult, HandlerName) -> + case ?file_write(Fd, Bin) of + ok -> + ok; + PrevWriteResult -> + %% don't report same error twice + PrevWriteResult; + Error -> + logger_h_common:error_notify({HandlerName,write,FileName,Error}), + Error + end. + +sync_dev(Fd, DevName, PrevSyncResult, HandlerName) -> + case ?file_datasync(Fd) of + ok -> + ok; + PrevSyncResult -> + %% don't report same error twice + PrevSyncResult; + Error -> + logger_h_common:error_notify({HandlerName,filesync,DevName,Error}), + Error + end. + |