%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 1996-2019. 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(sys). %% External exports -export([suspend/1, suspend/2, resume/1, resume/2, get_status/1, get_status/2, get_state/1, get_state/2, replace_state/2, replace_state/3, change_code/4, change_code/5, terminate/2, terminate/3, log/2, log/3, trace/2, trace/3, statistics/2, statistics/3, log_to_file/2, log_to_file/3, no_debug/1, no_debug/2, install/2, install/3, remove/2, remove/3]). -export([handle_system_msg/6, handle_system_msg/7, handle_debug/4, print_log/1, get_log/1, get_debug/3, debug_options/1, suspend_loop_hib/6]). -deprecated([{get_debug,3,eventually}]). %%----------------------------------------------------------------- %% Types %%----------------------------------------------------------------- -export_type([dbg_opt/0, dbg_fun/0, debug_option/0]). -type name() :: pid() | atom() | {'global', term()} | {'via', module(), term()}. -type system_event() :: {'in', Msg :: _} | {'in', Msg :: _, State :: _} | {'out', Msg :: _, To :: _} | {'out', Msg :: _, To :: _, State :: _} | {'noreply', State :: _} | {'continue', Continuation :: _} | {'code_change', Event :: _, State :: _} | {'postpone', Event :: _, State :: _, NextState :: _} | {'consume', Event :: _, State :: _, NextState :: _} | {'start_timer', Action :: _, State :: _} | {'insert_timeout', Event :: _, State :: _} | {'enter', State :: _} | {'terminate', Reason :: _, State :: _} | term(). -opaque dbg_opt() :: {'trace', 'true'} | {'log', {N :: non_neg_integer(), [{Event :: system_event(), FuncState :: _, FormFunc :: format_fun()}]}} | {'statistics', {file:date_time(), {'reductions', non_neg_integer()}, MessagesIn :: non_neg_integer(), MessagesOut :: non_neg_integer()}} | {'log_to_file', file:io_device()} | {Func :: dbg_fun(), FuncState :: term()} | {FuncId :: term(), Func :: dbg_fun(), FuncState :: term()}. -type dbg_fun() :: fun((FuncState :: _, Event :: system_event(), ProcState :: _) -> 'done' | (NewFuncState :: _)). -type format_fun() :: fun((Device :: io:device() | file:io_device(), Event :: system_event(), Extra :: term()) -> any()). -type debug_option() :: 'trace' | 'log' | {'log', N :: pos_integer()} | 'statistics' | {'log_to_file', FileName :: file:name()} | {'install', {Func :: dbg_fun(), FuncState :: term()} | {FuncId :: term(), Func :: dbg_fun(), FuncState :: term()}}. %%----------------------------------------------------------------- %% System messages %%----------------------------------------------------------------- -spec suspend(Name) -> 'ok' when Name :: name(). suspend(Name) -> send_system_msg(Name, suspend). -spec suspend(Name, Timeout) -> 'ok' when Name :: name(), Timeout :: timeout(). suspend(Name, Timeout) -> send_system_msg(Name, suspend, Timeout). -spec resume(Name) -> 'ok' when Name :: name(). resume(Name) -> send_system_msg(Name, resume). -spec resume(Name, Timeout) -> 'ok' when Name :: name(), Timeout :: timeout(). resume(Name, Timeout) -> send_system_msg(Name, resume, Timeout). -spec get_status(Name) -> Status when Name :: name(), Status :: {status, Pid :: pid(), {module, Module :: module()}, [SItem]}, SItem :: (PDict :: [{Key :: term(), Value :: term()}]) | (SysState :: 'running' | 'suspended') | (Parent :: pid()) | (Dbg :: [dbg_opt()]) | (Misc :: term()). get_status(Name) -> send_system_msg(Name, get_status). -spec get_status(Name, Timeout) -> Status when Name :: name(), Timeout :: timeout(), Status :: {status, Pid :: pid(), {module, Module :: module()}, [SItem]}, SItem :: (PDict :: [{Key :: term(), Value :: term()}]) | (SysState :: 'running' | 'suspended') | (Parent :: pid()) | (Dbg :: [dbg_opt()]) | (Misc :: term()). get_status(Name, Timeout) -> send_system_msg(Name, get_status, Timeout). -spec get_state(Name) -> State when Name :: name(), State :: term(). get_state(Name) -> case send_system_msg(Name, get_state) of {error, Reason} -> error(Reason); State -> State end. -spec get_state(Name, Timeout) -> State when Name :: name(), Timeout :: timeout(), State :: term(). get_state(Name, Timeout) -> case send_system_msg(Name, get_state, Timeout) of {error, Reason} -> error(Reason); State -> State end. -spec replace_state(Name, StateFun) -> NewState when Name :: name(), StateFun :: fun((State :: term()) -> NewState :: term()), NewState :: term(). replace_state(Name, StateFun) -> case send_system_msg(Name, {replace_state, StateFun}) of {error, Reason} -> error(Reason); State -> State end. -spec replace_state(Name, StateFun, Timeout) -> NewState when Name :: name(), StateFun :: fun((State :: term()) -> NewState :: term()), Timeout :: timeout(), NewState :: term(). replace_state(Name, StateFun, Timeout) -> case send_system_msg(Name, {replace_state, StateFun}, Timeout) of {error, Reason} -> error(Reason); State -> State end. -spec change_code(Name, Module, OldVsn, Extra) -> 'ok' | {error, Reason} when Name :: name(), Module :: module(), OldVsn :: 'undefined' | term(), Extra :: term(), Reason :: term(). change_code(Name, Mod, Vsn, Extra) -> send_system_msg(Name, {change_code, Mod, Vsn, Extra}). -spec change_code(Name, Module, OldVsn, Extra, Timeout) -> 'ok' | {error, Reason} when Name :: name(), Module :: module(), OldVsn :: 'undefined' | term(), Extra :: term(), Timeout :: timeout(), Reason :: term(). change_code(Name, Mod, Vsn, Extra, Timeout) -> send_system_msg(Name, {change_code, Mod, Vsn, Extra}, Timeout). -spec terminate(Name, Reason) -> 'ok' when Name :: name(), Reason :: term(). terminate(Name, Reason) -> send_system_msg(Name, {terminate, Reason}). -spec terminate(Name, Reason, Timeout) -> 'ok' when Name :: name(), Reason :: term(), Timeout :: timeout(). terminate(Name, Reason, Timeout) -> send_system_msg(Name, {terminate, Reason}, Timeout). %%----------------------------------------------------------------- %% Debug commands %%----------------------------------------------------------------- -spec log(Name, Flag) -> 'ok' | {'ok', [system_event()]} when Name :: name(), Flag :: 'true' | {'true', N :: pos_integer()} | 'false' | 'get' | 'print'. log(Name, Flag) -> send_system_msg(Name, {debug, {log, Flag}}). -spec log(Name, Flag, Timeout) -> 'ok' | {'ok', [system_event()]} when Name :: name(), Flag :: 'true' | {'true', N :: pos_integer()} | 'false' | 'get' | 'print', Timeout :: timeout(). log(Name, Flag, Timeout) -> send_system_msg(Name, {debug, {log, Flag}}, Timeout). -spec trace(Name, Flag) -> 'ok' when Name :: name(), Flag :: boolean(). trace(Name, Flag) -> send_system_msg(Name, {debug, {trace, Flag}}). -spec trace(Name, Flag, Timeout) -> 'ok' when Name :: name(), Flag :: boolean(), Timeout :: timeout(). trace(Name, Flag, Timeout) -> send_system_msg(Name, {debug, {trace, Flag}}, Timeout). -spec log_to_file(Name, Flag) -> 'ok' | {'error','open_file'} when Name :: name(), Flag :: (FileName :: string()) | 'false'. log_to_file(Name, FileName) -> send_system_msg(Name, {debug, {log_to_file, FileName}}). -spec log_to_file(Name, Flag, Timeout) -> 'ok' | {'error','open_file'} when Name :: name(), Flag :: (FileName :: string()) | 'false', Timeout :: timeout(). log_to_file(Name, FileName, Timeout) -> send_system_msg(Name, {debug, {log_to_file, FileName}}, Timeout). -spec statistics(Name, Flag) -> 'ok' | {'ok', Statistics} when Name :: name(), Flag :: 'true' | 'false' | 'get', Statistics :: [StatisticsTuple] | no_statistics, StatisticsTuple :: {'start_time', DateTime1} | {'current_time', DateTime2} | {'reductions', non_neg_integer()} | {'messages_in', non_neg_integer()} | {'messages_out', non_neg_integer()}, DateTime1 :: file:date_time(), DateTime2 :: file:date_time(). statistics(Name, Flag) -> send_system_msg(Name, {debug, {statistics, Flag}}). -spec statistics(Name, Flag, Timeout) -> 'ok' | {'ok', Statistics} when Name :: name(), Flag :: 'true' | 'false' | 'get', Statistics :: [StatisticsTuple] | no_statistics, StatisticsTuple :: {'start_time', DateTime1} | {'current_time', DateTime2} | {'reductions', non_neg_integer()} | {'messages_in', non_neg_integer()} | {'messages_out', non_neg_integer()}, DateTime1 :: file:date_time(), DateTime2 :: file:date_time(), Timeout :: timeout(). statistics(Name, Flag, Timeout) -> send_system_msg(Name, {debug, {statistics, Flag}}, Timeout). -spec no_debug(Name) -> 'ok' when Name :: name(). no_debug(Name) -> send_system_msg(Name, {debug, no_debug}). -spec no_debug(Name, Timeout) -> 'ok' when Name :: name(), Timeout :: timeout(). no_debug(Name, Timeout) -> send_system_msg(Name, {debug, no_debug}, Timeout). -spec install(Name, FuncSpec) -> 'ok' when Name :: name(), FuncSpec :: {Func, FuncState} | {FuncId, Func, FuncState}, FuncId :: term(), Func :: dbg_fun(), FuncState :: term(). install(Name, {Func, FuncState}) -> send_system_msg(Name, {debug, {install, {Func, FuncState}}}); install(Name, {FuncId, Func, FuncState}) -> send_system_msg(Name, {debug, {install, {FuncId, Func, FuncState}}}). -spec install(Name, FuncSpec, Timeout) -> 'ok' when Name :: name(), FuncSpec :: {Func, FuncState} | {FuncId, Func, FuncState}, FuncId :: term(), Func :: dbg_fun(), FuncState :: term(), Timeout :: timeout(). install(Name, {Func, FuncState}, Timeout) -> send_system_msg(Name, {debug, {install, {Func, FuncState}}}, Timeout); install(Name, {FuncId, Func, FuncState}, Timeout) -> send_system_msg(Name, {debug, {install, {FuncId, Func, FuncState}}}, Timeout). -spec remove(Name, Func | FuncId) -> 'ok' when Name :: name(), Func :: dbg_fun(), FuncId :: term(). remove(Name, FuncOrFuncId) -> send_system_msg(Name, {debug, {remove, FuncOrFuncId}}). -spec remove(Name, Func | FuncId, Timeout) -> 'ok' when Name :: name(), Func :: dbg_fun(), FuncId :: term(), Timeout :: timeout(). remove(Name, FuncOrFuncId, Timeout) -> send_system_msg(Name, {debug, {remove, FuncOrFuncId}}, Timeout). %%----------------------------------------------------------------- %% All system messages sent are on the form {system, From, Msg} %% The receiving side should send Msg to handle_system_msg/5. %%----------------------------------------------------------------- send_system_msg(Name, Request) -> case catch gen:call(Name, system, Request) of {ok,Res} -> Res; {'EXIT', Reason} -> exit({Reason, mfa(Name, Request)}) end. send_system_msg(Name, Request, Timeout) -> case catch gen:call(Name, system, Request, Timeout) of {ok,Res} -> Res; {'EXIT', Reason} -> exit({Reason, mfa(Name, Request, Timeout)}) end. mfa(Name, {debug, {Func, Arg2}}) -> {sys, Func, [Name, Arg2]}; mfa(Name, {change_code, Mod, Vsn, Extra}) -> {sys, change_code, [Name, Mod, Vsn, Extra]}; mfa(Name, {terminate, Reason}) -> {sys, terminate, [Name, Reason]}; mfa(Name, Atom) -> {sys, Atom, [Name]}. mfa(Name, Req, Timeout) -> {M, F, A} = mfa(Name, Req), {M, F, A ++ [Timeout]}. %%----------------------------------------------------------------- %% Func: handle_system_msg/6 %% Purpose: Used by a process module that wishes to take care of %% system messages. The process receives a {system, From, %% Msg} message, and passes the Msg to this function. %% Returns: This function *never* returns! It calls the function %% Module:system_continue(Parent, NDebug, Misc) %% there the process continues the execution or %% Module:system_terminate(Reason, Parent, Debug, Misc) if %% the process should terminate. %% The Module must export system_continue/3, system_terminate/4 %% and format_status/2 for status information. %%----------------------------------------------------------------- -spec handle_system_msg(Msg, From, Parent, Module, Debug, Misc) -> no_return() when Msg :: term(), From :: {pid(), Tag :: _}, Parent :: pid(), Module :: module(), Debug :: [dbg_opt()], Misc :: term(). handle_system_msg(Msg, From, Parent, Module, Debug, Misc) -> handle_system_msg(running, Msg, From, Parent, Module, Debug, Misc, false). handle_system_msg(Msg, From, Parent, Mod, Debug, Misc, Hib) -> handle_system_msg(running, Msg, From, Parent, Mod, Debug, Misc, Hib). handle_system_msg(SysState, Msg, From, Parent, Mod, Debug, Misc, Hib) -> case do_cmd(SysState, Msg, Parent, Mod, Debug, Misc) of {suspended, Reply, NDebug, NMisc} -> _ = gen:reply(From, Reply), suspend_loop(suspended, Parent, Mod, NDebug, NMisc, Hib); {running, Reply, NDebug, NMisc} -> _ = gen:reply(From, Reply), Mod:system_continue(Parent, NDebug, NMisc); {{terminating, Reason}, Reply, NDebug, NMisc} -> _ = gen:reply(From, Reply), Mod:system_terminate(Reason, Parent, NDebug, NMisc) end. %%----------------------------------------------------------------- %% Func: handle_debug/4 %% Purpose: Called by a process that wishes to debug an event. %% Func is a formatting function, called as Func(Device, Event). %% Returns: [debug_opts()] %%----------------------------------------------------------------- -spec handle_debug(Debug, FormFunc, Extra, Event) -> [dbg_opt()] when Debug :: [dbg_opt()], FormFunc :: format_fun(), Extra :: term(), Event :: system_event(). handle_debug([{trace, true} = DbgOpt | T], FormFunc, State, Event) -> print_event({Event, State, FormFunc}), [DbgOpt | handle_debug(T, FormFunc, State, Event)]; handle_debug([{log, NLog} | T], FormFunc, State, Event) -> Item = {Event, State, FormFunc}, [{log, nlog_put(Item, NLog)} | handle_debug(T, FormFunc, State, Event)]; handle_debug([{log_to_file, Fd} = DbgOpt | T], FormFunc, State, Event) -> print_event(Fd, {Event, State, FormFunc}), [DbgOpt | handle_debug(T, FormFunc, State, Event)]; handle_debug([{statistics, StatData} | T], FormFunc, State, Event) -> NStatData = stat(Event, StatData), [{statistics, NStatData} | handle_debug(T, FormFunc, State, Event)]; handle_debug([{FuncId, {Func, FuncState}} | T], FormFunc, State, Event) -> try Func(FuncState, Event, State) of done -> handle_debug(T, FormFunc, State, Event); NFuncState -> [{FuncId, {Func, NFuncState}} | handle_debug(T, FormFunc, State, Event)] catch done -> handle_debug(T, FormFunc, State, Event); NFuncState -> [{FuncId, {Func, NFuncState}} | handle_debug(T, FormFunc, State, Event)]; _:_ -> handle_debug(T, FormFunc, State, Event) end; handle_debug([{Func, FuncState} | T], FormFunc, State, Event) -> try Func(FuncState, Event, State) of done -> handle_debug(T, FormFunc, State, Event); NFuncState -> [{Func, NFuncState} | handle_debug(T, FormFunc, State, Event)] catch done -> handle_debug(T, FormFunc, State, Event); NFuncState -> [{Func, NFuncState} | handle_debug(T, FormFunc, State, Event)]; _:_ -> handle_debug(T, FormFunc, State, Event) end; handle_debug([], _FormFunc, _State, _Event) -> []. %%----------------------------------------------------------------- %% When a process is suspended, it can only respond to system %% messages. %%----------------------------------------------------------------- suspend_loop(SysState, Parent, Mod, Debug, Misc, Hib) -> case Hib of true -> suspend_loop_hib(SysState, Parent, Mod, Debug, Misc, Hib); _ -> receive {system, From, Msg} -> handle_system_msg(SysState, Msg, From, Parent, Mod, Debug, Misc, Hib); {'EXIT', Parent, Reason} -> Mod:system_terminate(Reason, Parent, Debug, Misc) end end. suspend_loop_hib(SysState, Parent, Mod, Debug, Misc, Hib) -> receive {system, From, Msg} -> handle_system_msg(SysState, Msg, From, Parent, Mod, Debug, Misc, Hib); {'EXIT', Parent, Reason} -> Mod:system_terminate(Reason, Parent, Debug, Misc) after 0 -> % Not a system message, go back into hibernation proc_lib:hibernate(?MODULE, suspend_loop_hib, [SysState, Parent, Mod, Debug, Misc, Hib]) end. do_cmd(_, suspend, _Parent, _Mod, Debug, Misc) -> {suspended, ok, Debug, Misc}; do_cmd(_, resume, _Parent, _Mod, Debug, Misc) -> {running, ok, Debug, Misc}; do_cmd(SysState, get_state, _Parent, Mod, Debug, Misc) -> {SysState, do_get_state(Mod, Misc), Debug, Misc}; do_cmd(SysState, {replace_state, StateFun}, _Parent, Mod, Debug, Misc) -> {Res, NMisc} = do_replace_state(StateFun, Mod, Misc), {SysState, Res, Debug, NMisc}; do_cmd(SysState, get_status, Parent, Mod, Debug, Misc) -> Res = get_status(SysState, Parent, Mod, Debug, Misc), {SysState, Res, Debug, Misc}; do_cmd(SysState, {debug, What}, _Parent, _Mod, Debug, Misc) -> {Res, NDebug} = debug_cmd(What, Debug), {SysState, Res, NDebug, Misc}; do_cmd(_, {terminate, Reason}, _Parent, _Mod, Debug, Misc) -> {{terminating, Reason}, ok, Debug, Misc}; do_cmd(suspended, {change_code, Module, Vsn, Extra}, _Parent, Mod, Debug, Misc) -> {Res, NMisc} = do_change_code(Mod, Module, Vsn, Extra, Misc), {suspended, Res, Debug, NMisc}; do_cmd(SysState, Other, _Parent, _Mod, Debug, Misc) -> {SysState, {error, {unknown_system_msg, Other}}, Debug, Misc}. do_get_state(Mod, Misc) -> case erlang:function_exported(Mod, system_get_state, 1) of true -> try {ok, State} = Mod:system_get_state(Misc), State catch Cl:Exc -> {error, {callback_failed,{Mod,system_get_state},{Cl,Exc}}} end; false -> Misc end. do_replace_state(StateFun, Mod, Misc) -> case erlang:function_exported(Mod, system_replace_state, 2) of true -> try {ok, State, NMisc} = Mod:system_replace_state(StateFun, Misc), {State, NMisc} catch Cl:Exc -> {{error, {callback_failed,{Mod,system_replace_state},{Cl,Exc}}}, Misc} end; false -> try NMisc = StateFun(Misc), {NMisc, NMisc} catch Cl:Exc -> {{error, {callback_failed,StateFun,{Cl,Exc}}}, Misc} end end. get_status(SysState, Parent, Mod, Debug, Misc) -> PDict = get(), FmtMisc = case erlang:function_exported(Mod, format_status, 2) of true -> FmtArgs = [PDict, SysState, Parent, Debug, Misc], Mod:format_status(normal, FmtArgs); _ -> Misc end, {status, self(), {module, Mod}, [PDict, SysState, Parent, Debug, FmtMisc]}. %%----------------------------------------------------------------- %% These are the system debug commands. %% {trace, true|false} -> io:format %% {log, true|false|get|print} -> keeps the 10 last debug messages %% {log_to_file, FileName | false} -> io:format to file. %% {statistics, true|false|get} -> keeps track of messages in/out + reds. %%----------------------------------------------------------------- debug_cmd({trace, true}, Debug) -> {ok, install_debug(trace, true, Debug)}; debug_cmd({trace, false}, Debug) -> {ok, remove_debug(trace, Debug)}; debug_cmd({log, true}, Debug) -> NLog = get_debug(log, Debug, nlog_new()), {ok, install_debug(log, nlog_new(NLog), Debug)}; debug_cmd({log, {true, N}}, Debug) when is_integer(N), 1 =< N -> NLog = get_debug(log, Debug, nlog_new(N)), {ok, install_debug(log, nlog_new(N, NLog), Debug)}; debug_cmd({log, false}, Debug) -> {ok, remove_debug(log, Debug)}; debug_cmd({log, print}, Debug) -> print_log(Debug), {ok, Debug}; debug_cmd({log, get}, Debug) -> NLog = get_debug(log, Debug, nlog_new()), {{ok, [Event || {Event, _State, _FormFunc} <- nlog_get(NLog)]}, Debug}; debug_cmd({log_to_file, false}, Debug) -> NDebug = close_log_file(Debug), {ok, NDebug}; debug_cmd({log_to_file, FileName}, Debug) -> NDebug = close_log_file(Debug), case file:open(FileName, [write,{encoding,utf8}]) of {ok, Fd} -> {ok, install_debug(log_to_file, Fd, NDebug)}; _Error -> {{error, open_file}, NDebug} end; debug_cmd({statistics, true}, Debug) -> {ok, install_debug(statistics, init_stat(), Debug)}; debug_cmd({statistics, false}, Debug) -> {ok, remove_debug(statistics, Debug)}; debug_cmd({statistics, get}, Debug) -> {{ok, get_stat(get_debug(statistics, Debug, []))}, Debug}; debug_cmd(no_debug, Debug) -> close_log_file(Debug), {ok, []}; debug_cmd({install, {Func, FuncState}}, Debug) -> {ok, install_debug(Func, FuncState, Debug)}; debug_cmd({install, {FuncId, Func, FuncState}}, Debug) -> {ok, install_debug(FuncId, {Func, FuncState}, Debug)}; debug_cmd({remove, FuncOrFuncId}, Debug) -> {ok, remove_debug(FuncOrFuncId, Debug)}; debug_cmd(_Unknown, Debug) -> {unknown_debug, Debug}. do_change_code(Mod, Module, Vsn, Extra, Misc) -> case catch Mod:system_code_change(Misc, Module, Vsn, Extra) of {ok, NMisc} -> {ok, NMisc}; Else -> {{error, Else}, Misc} end. print_event(X) -> print_event(standard_io, X). print_event(Dev, {Event, State, FormFunc}) -> FormFunc(Dev, Event, State). init_stat() -> {erlang:localtime(), process_info(self(), reductions), 0, 0}. get_stat({Time, {reductions, Reds}, In, Out}) -> {reductions, Reds2} = process_info(self(), reductions), [{start_time, Time}, {current_time, erlang:localtime()}, {reductions, Reds2 - Reds}, {messages_in, In}, {messages_out, Out}]; get_stat(_) -> no_statistics. stat({in, _Msg}, {Time, Reds, In, Out}) -> {Time, Reds, In+1, Out}; stat({in, _Msg, _From}, {Time, Reds, In, Out}) -> {Time, Reds, In+1, Out}; stat({out, _Msg, _To}, {Time, Reds, In, Out}) -> {Time, Reds, In, Out+1}; stat({out, _Msg, _To, _State}, {Time, Reds, In, Out}) -> {Time, Reds, In, Out+1}; stat(_, StatData) -> StatData. %%----------------------------------------------------------------- %% Debug structure manipulating functions %%----------------------------------------------------------------- install_debug(Item, Data, Debug) -> case lists:keysearch(Item, 1, Debug) of false -> [{Item, Data} | Debug]; _ -> Debug end. remove_debug(Item, Debug) -> lists:keydelete(Item, 1, Debug). -spec get_debug(Item, Debug, Default) -> term() when Item :: 'log' | 'statistics', Debug :: [dbg_opt()], Default :: term(). get_debug(Item, Debug, Default) -> get_debug2(Item, Debug, Default). %% Workaround: accepts more Item types than get_debug/3. get_debug2(Item, Debug, Default) -> case lists:keysearch(Item, 1, Debug) of {value, {Item, Data}} -> Data; _ -> Default end. -spec print_log(Debug) -> 'ok' when Debug :: [dbg_opt()]. print_log(Debug) -> NLog = get_debug(log, Debug, nlog_new()), lists:foreach(fun print_event/1, nlog_get(NLog)). -spec get_log(Debug) -> [system_event()] when Debug :: [dbg_opt()]. get_log(Debug) -> NLog = get_debug(log, Debug, nlog_new()), [Event || {Event, _State, _FormFunc} <- nlog_get(NLog)]. close_log_file(Debug) -> case get_debug2(log_to_file, Debug, []) of [] -> Debug; Fd -> ok = file:close(Fd), remove_debug(log_to_file, Debug) end. %%----------------------------------------------------------------- %% Keep the last N Log functions %%----------------------------------------------------------------- %% %% Streamlined Okasaki queue as base for "keep the last N" log. %% %% To the reverse list head we cons new items. %% The forward list contains elements in insertion order, %% so the head is the oldest and the one to drop off %% when the log is full. %% %% Here is how we can get away with only using one cons cell %% to wrap the forward and reverse list, and the log size: %% %% A full log does not need a counter; we just cons one %% and drop one: %% %% [ReverseList|ForwardList] %% %% A non-full log is filling up to N elements; %% use a down counter instead of a list as first element: %% %% [RemainingToFullCount|ReverseList] nlog_new() -> nlog_new(10). %% nlog_new([_|_] = NLog) -> nlog_new(10, NLog); nlog_new(N) -> [N]. % Empty log size N >= 1 %% nlog_new(N, NLog) -> lists:foldl( fun (Item, NL) -> nlog_put(Item, NL) end, nlog_new(N), nlog_get(NLog)). %% nlog_put(Item, NLog) -> case NLog of [R|FF] when is_list(R) -> %% Full log case FF of [_|F] -> %% Cons to reverse list, drop from forward list [[Item|R]|F]; [] -> %% Create new forward list from reverse list, %% create new empty reverse list [_|F] = lists:reverse(R, [Item]), [[]|F] end; [1|R] -> %% Log now gets full [[Item|R]]; [J|R] -> %% Filling up to N elements [J - 1,Item|R] end. nlog_get([[]|F]) -> F; nlog_get([[_|_] = R|F]) -> F ++ lists:reverse(R); nlog_get([_J|R]) -> lists:reverse(R). %%----------------------------------------------------------------- %% Func: debug_options/1 %% Purpose: Initiate a debug structure. Called by a process that %% wishes to initiate the debug structure without the %% system messages. %% Returns: [debug_opts()] %%----------------------------------------------------------------- -spec debug_options([Opt :: debug_option()]) -> [dbg_opt()]. debug_options(Options) -> debug_options(Options, []). debug_options([trace | T], Debug) -> debug_options(T, install_debug(trace, true, Debug)); debug_options([log | T], Debug) -> debug_options(T, install_debug(log, nlog_new(), Debug)); debug_options([{log, N} | T], Debug) when is_integer(N), N > 0 -> debug_options(T, install_debug(log, nlog_new(N), Debug)); debug_options([statistics | T], Debug) -> debug_options(T, install_debug(statistics, init_stat(), Debug)); debug_options([{log_to_file, FileName} | T], Debug) -> case file:open(FileName, [write,{encoding,utf8}]) of {ok, Fd} -> debug_options(T, install_debug(log_to_file, Fd, Debug)); _Error -> debug_options(T, Debug) end; debug_options([{install, {Func, FuncState}} | T], Debug) -> debug_options(T, install_debug(Func, FuncState, Debug)); debug_options([{install, {FuncId, Func, FuncState}} | T], Debug) -> debug_options(T, install_debug(FuncId, {Func, FuncState}, Debug)); debug_options([_ | T], Debug) -> debug_options(T, Debug); debug_options([], Debug) -> Debug.