%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1998-2016. 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(dbg_iserver).
-behaviour(gen_server).
%% External exports
-export([start/0, stop/0, find/0,
call/1, call/2, cast/1, cast/2, safe_call/1, safe_cast/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-record(proc, {pid, % pid() Debugged process
meta, % pid() Meta process
attpid, % pid() | undefined Attached process
status, % running | exit | idle | waiting
info = {}, % {} | term()
exit_info= {}, % {} | {{Mod,Line}, Bs, Stack}
function % {Mod,Func,Args} Initial function call
}).
-record(state, {db, % ETS table
procs = [], % [#proc{}]
breaks = [], % [{{M,L},Options} Breakpoints
auto, % Auto attach settings
stack, % Stack trace settings
subs = [] % [pid()] Subscribers (Debugger)
}).
%%====================================================================
%% External exports
%%====================================================================
start() ->
gen_server:start({local, ?MODULE}, ?MODULE, [], []).
stop() ->
gen_server:cast(?MODULE, stop).
find() ->
global:whereis_name(?MODULE).
call(Request) ->
gen_server:call(?MODULE, Request, infinity).
call(Int, Request) ->
gen_server:call(Int, Request, infinity).
cast(Request) ->
gen_server:cast(?MODULE, Request).
cast(Int, Request) ->
gen_server:cast(Int, Request).
safe_call(Request) ->
ensure_started(),
call(Request).
safe_cast(Request) ->
ensure_started(),
cast(Request).
ensure_started() ->
case whereis(?MODULE) of
undefined -> start();
_Pid -> ignore
end.
%%--Module database---------------------------------------------------
%% This server creates an ETS table, where the following information
%% is saved:
%%
%% Key Value
%% --- -----
%% {Mod, refs} [ModDb]
%% ModDb [pid()]
%%
%% In each ModDb, the following information is saved by dbg_iload:
%%
%% Key Value
%% --- -----
%% defs []
%% mod_bin Binary
%% mod_raw Raw Binary
%% mod_file File
%% {Mod,Name,Arity,Exported} Cs
%% {'fun',Mod,Index,Uniq} {Name,Arity,Cs}
%% Line {Pos,PosNL}
%%====================================================================
%% gen_server callbacks
%%====================================================================
init([]) ->
process_flag(trap_exit, true),
global:register_name(?MODULE, self()),
Db = ets:new(?MODULE, [ordered_set, protected]),
{ok, #state{db=Db, auto=false, stack=no_tail}}.
%% Attaching to a process
handle_call({attached, AttPid, Pid}, _From, State) ->
{true, Proc} = get_proc({pid, Pid}, State#state.procs),
case Proc#proc.attpid of
undefined ->
link(AttPid),
case Proc#proc.status of
exit ->
Args = [self(),
AttPid,Pid,Proc#proc.info,
Proc#proc.exit_info],
Meta = spawn_link(dbg_ieval, exit_info, Args),
Proc2 = Proc#proc{meta=Meta, attpid=AttPid},
Procs = lists:keyreplace(Pid, #proc.pid,
State#state.procs, Proc2),
{reply, {ok,Meta}, State#state{procs=Procs}};
_Status ->
Meta = Proc#proc.meta,
send(Meta, {attached, AttPid}),
Procs = lists:keyreplace(Pid, #proc.pid,
State#state.procs,
Proc#proc{attpid=AttPid}),
{reply, {ok, Meta}, State#state{procs=Procs}}
end;
_AttPid -> % there is already an attached process
{reply, error, State}
end;
%% Getting and setting options
handle_call(get_auto_attach, _From, State) ->
{reply, State#state.auto, State};
handle_call(get_stack_trace, _From, State) ->
{reply, State#state.stack, State};
%% Retrieving information
handle_call(snapshot, _From, State) ->
Reply = [{Proc#proc.pid, Proc#proc.function,
Proc#proc.status, Proc#proc.info} || Proc <- State#state.procs],
{reply, Reply, State};
handle_call({get_meta, Pid}, _From, State) ->
Reply = case get_proc({pid, Pid}, State#state.procs) of
{true, Proc} ->
{ok, Proc#proc.meta};
false ->
{error, not_interpreted}
end,
{reply, Reply, State};
handle_call({get_attpid, Pid}, _From, State) ->
Reply = case get_proc({pid, Pid}, State#state.procs) of
{true, Proc} ->
{ok, Proc#proc.attpid};
false ->
{error, not_interpreted}
end,
{reply, Reply, State};
%% Breakpoint handling
handle_call({new_break, Point, Options}, _From, State) ->
case lists:keymember(Point, 1, State#state.breaks) of
false ->
Break = {Point, Options},
send_all([subscriber, meta, attached],
{new_break, Break}, State),
Breaks = keyinsert(Break, 1, State#state.breaks),
{reply, ok, State#state{breaks=Breaks}};
true ->
{reply, {error, break_exists}, State}
end;
handle_call(all_breaks, _From, State) ->
{reply, State#state.breaks, State};
handle_call({all_breaks, Mod}, _From, State) ->
Reply = [Break || Break = {{M, _},_} <- State#state.breaks, M =:= Mod],
{reply, Reply, State};
%% From Meta process
handle_call({new_process, Pid, Meta, Function}, _From, State) ->
link(Meta),
%% A new, debugged process has been started. Return its status,
%% ie running (running as usual) or break (stop)
%% The status depends on if the process is automatically attached to
%% or not.
Reply = case auto_attach(init, State#state.auto, Pid) of
AttPid when is_pid(AttPid) -> break;
ignore -> running
end,
%% Do not add AttPid, it should call attached/2 when started instead
Proc = #proc{pid=Pid, meta=Meta, status=running, function=Function},
send_all(subscriber,
{new_process, {Pid,Function,running,{}}}, State),
{reply, Reply, State#state{procs=State#state.procs++[Proc]}};
%% Code loading
handle_call({load, Mod, Src, Bin}, _From, State) ->
%% Create an ETS table for storing information about the module
Db = State#state.db,
ModDb = ets:new(Mod, [ordered_set, public]),
ModDbs = case ets:lookup(Db, {Mod, refs}) of
[] -> [];
[{{Mod, refs}, ModDbs1}] -> ModDbs1
end,
ets:insert(Db, {{Mod, refs}, [ModDb|ModDbs]}),
ets:insert(Db, {ModDb, []}),
%% Load the code
{ok, Mod} = dbg_iload:load_mod(Mod, Src, Bin, ModDb),
%% Inform all subscribers and attached processes
send_all([subscriber, attached], {interpret, Mod}, State),
{reply, {module, Mod}, State};
%% Module database
handle_call({get_module_db, Mod, Pid}, _From, State) ->
Db = State#state.db,
Reply = case ets:lookup(Db, {Mod, refs}) of
[] -> not_found;
[{{Mod, refs}, [ModDb|_ModDbs]}] ->
[{ModDb, Pids}] = ets:lookup(Db, ModDb),
ets:insert(Db, {ModDb, [Pid|Pids]}),
ModDb
end,
{reply, Reply, State};
handle_call({lookup, Mod, Key}, _From, State) ->
Db = State#state.db,
Reply = case ets:lookup(Db, {Mod, refs}) of
[] -> not_found;
[{{Mod, refs}, [ModDb|_ModDbs]}] ->
case ets:lookup(ModDb, Key) of
[] -> not_found;
[{Key, Value}] -> {ok, Value}
end
end,
{reply, Reply, State};
handle_call({functions, Mod}, _From, State) ->
Db = State#state.db,
Reply = case ets:lookup(Db, {Mod, refs}) of
[] -> [];
[{{Mod, refs}, [ModDb|_ModDbs]}] ->
Pattern = {{Mod,'$1','$2','_'}, '_'},
ets:match(ModDb, Pattern)
end,
{reply, Reply, State};
handle_call({contents, Mod, Pid}, _From, State) ->
Db = State#state.db,
[{{Mod, refs}, ModDbs}] = ets:lookup(Db, {Mod, refs}),
ModDb = if
Pid =:= any -> hd(ModDbs);
true ->
lists:foldl(fun(T, not_found) ->
[{T, Pids}] = ets:lookup(Db, T),
case lists:member(Pid, Pids) of
true -> T;
false -> not_found
end;
(_T, T) -> T
end,
not_found,
ModDbs)
end,
[{mod_bin, Bin}] = ets:lookup(ModDb, mod_bin),
{reply, {ok, Bin}, State};
handle_call({raw_contents, Mod, Pid}, _From, State) ->
Db = State#state.db,
[{{Mod, refs}, ModDbs}] = ets:lookup(Db, {Mod, refs}),
ModDb = if
Pid =:= any -> hd(ModDbs);
true ->
lists:foldl(fun(T, not_found) ->
[{T, Pids}] = ets:lookup(Db, T),
case lists:member(Pid, Pids) of
true -> T;
false -> not_found
end;
(_T, T) -> T
end,
not_found,
ModDbs)
end,
[{mod_raw, Bin}] = ets:lookup(ModDb, mod_raw),
{reply, {ok, Bin}, State};
handle_call({is_interpreted, Mod, Name, Arity}, _From, State) ->
Db = State#state.db,
Reply = case ets:lookup(Db, {Mod, refs}) of
[] -> false;
[{{Mod, refs}, [ModDb|_ModDbs]}] ->
Pattern = {{Mod,Name,Arity,'_'}, '_'},
case ets:match_object(ModDb, Pattern) of
[{_Key, Clauses}] -> {true, Clauses};
[] -> false
end
end,
{reply, Reply, State};
handle_call(all_interpreted, _From, State) ->
Db = State#state.db,
Mods = ets:select(Db, [{{{'$1',refs},'_'},[],['$1']}]),
{reply, Mods, State};
handle_call({file, Mod}, From, State) ->
{reply, Res, _} = handle_call({lookup, Mod, mod_file}, From, State),
Reply = case Res of
{ok, File} -> File;
not_found -> {error, not_loaded}
end,
{reply, Reply, State}.
handle_cast(stop, State) ->
{stop, shutdown, State};
handle_cast({subscribe, Sub}, State) ->
{noreply, State#state{subs=[Sub|State#state.subs]}};
%% Attaching to a process
handle_cast({attach, Pid, {Mod, Func, Args}}, State) ->
%% Simply spawn process, which should call int:attached(Pid)
spawn(Mod, Func, [Pid | Args]),
{noreply, State};
%% Getting and setting options
handle_cast({set_auto_attach, false}, State) ->
send_all(subscriber, {auto_attach, false}, State),
{noreply, State#state{auto=false}};
handle_cast({set_auto_attach, Flags, Function}, State) ->
send_all(subscriber, {auto_attach, {Flags, Function}}, State),
{noreply, State#state{auto={Flags, Function}}};
handle_cast({set_stack_trace, Flag}, State) ->
send_all(subscriber, {stack_trace, Flag}, State),
{noreply, State#state{stack=Flag}};
%% Retrieving information
handle_cast(clear, State) ->
Procs = lists:filter(fun(#proc{status=Status}) ->
Status =/= exit
end,
State#state.procs),
{noreply, State#state{procs=Procs}};
%% Breakpoint handling
handle_cast({delete_break, Point}, State) ->
case lists:keymember(Point, 1, State#state.breaks) of
true ->
send_all([subscriber, meta, attached],
{delete_break, Point}, State),
Breaks = lists:keydelete(Point, 1, State#state.breaks),
{noreply, State#state{breaks=Breaks}};
false ->
{noreply, State}
end;
handle_cast({break_option, Point, Option, Value}, State) ->
case lists:keyfind(Point, 1, State#state.breaks) of
{Point, Options} ->
N = case Option of
status -> 1;
action -> 2;
condition -> 4
end,
Options2 = list_setelement(N, Options, Value),
send_all([subscriber, meta, attached],
{break_options, {Point, Options2}}, State),
Breaks = lists:keyreplace(Point, 1, State#state.breaks,
{Point, Options2}),
{noreply, State#state{breaks=Breaks}};
false ->
{noreply, State}
end;
handle_cast(no_break, State) ->
send_all([subscriber, meta, attached], no_break, State),
{noreply, State#state{breaks=[]}};
handle_cast({no_break, Mod}, State) ->
send_all([subscriber, meta, attached], {no_break, Mod}, State),
Breaks = lists:filter(fun({{M, _L}, _O}) ->
M =/= Mod
end,
State#state.breaks),
{noreply, State#state{breaks=Breaks}};
%% From Meta process
handle_cast({set_status, Meta, Status, Info}, State) ->
{true, Proc} = get_proc({meta, Meta}, State#state.procs),
send_all(subscriber, {new_status, Proc#proc.pid, Status, Info}, State),
if
Status =:= break ->
auto_attach(break, State#state.auto, Proc);
true -> ignore
end,
Proc2 = Proc#proc{status=Status, info=Info},
{noreply, State#state{procs=lists:keyreplace(Meta, #proc.meta,
State#state.procs, Proc2)}};
handle_cast({set_exit_info, Meta, ExitInfo}, State) ->
{true, Proc} = get_proc({meta, Meta}, State#state.procs),
Procs = lists:keyreplace(Meta, #proc.meta, State#state.procs,
Proc#proc{exit_info=ExitInfo}),
{noreply,State#state{procs=Procs}};
%% Code loading
handle_cast({delete, Mod}, State) ->
%% Remove the ETS table with information about the module
Db = State#state.db,
case ets:lookup(Db, {Mod, refs}) of
[] -> % Mod is not interpreted
{noreply, State};
[{{Mod, refs}, ModDbs}] ->
ets:delete(Db, {Mod, refs}),
AllPids = lists:foldl(
fun(ModDb, PidsAcc) ->
[{ModDb, Pids}] = ets:lookup(Db, ModDb),
ets:delete(Db, ModDb),
ets:delete(ModDb),
PidsAcc++Pids
end,
[],
ModDbs),
lists:foreach(fun(Pid) ->
case get_proc({pid, Pid},
State#state.procs) of
{true, Proc} ->
send(Proc#proc.meta,
{old_code, Mod});
false -> ignore % pid may have exited
end
end,
AllPids),
send_all([subscriber,attached], {no_interpret, Mod}, State),
%% Remove all breakpoints for Mod
handle_cast({no_break, Mod}, State)
end.
%% Process exits
handle_info({'EXIT',Who,Why}, State) ->
case get_proc({meta, Who}, State#state.procs) of
%% Exited process is a meta process for exit_info
{true,#proc{status=exit}} ->
{noreply,State};
%% Exited process is a meta process
{true,Proc} ->
Pid = Proc#proc.pid,
ExitInfo = Proc#proc.exit_info,
%% Check if someone is attached to the debugged process,
%% if so a new meta process should be started
Meta = case Proc#proc.attpid of
AttPid when is_pid(AttPid) ->
spawn_link(dbg_ieval, exit_info,
[self(),AttPid,Pid,Why,ExitInfo]);
undefined ->
%% Otherwise, auto attach if necessary
auto_attach(exit, State#state.auto, Pid),
Who
end,
send_all(subscriber, {new_status,Pid,exit,Why}, State),
Procs = lists:keyreplace(Who, #proc.meta, State#state.procs,
Proc#proc{meta=Meta,
status=exit,
info=Why}),
{noreply,State#state{procs=Procs}};
false ->
case get_proc({attpid, Who}, State#state.procs) of
%% Exited process is an attached process
{true, Proc} ->
%% If status==exit, then the meta process is a
%% simple meta for a terminated process and can be
%% terminated as well (it is only needed by
%% the attached process)
case Proc#proc.status of
exit -> send(Proc#proc.meta, stop);
_Status -> send(Proc#proc.meta, detached)
end,
Procs = lists:keyreplace(Proc#proc.pid, #proc.pid,
State#state.procs,
Proc#proc{attpid=undefined}),
{noreply, State#state{procs=Procs}};
%% Otherwise exited process must be a subscriber
false ->
Subs = lists:delete(Who, State#state.subs),
{noreply, State#state{subs=Subs}}
end
end.
terminate(_Reason, _State) ->
EbinDir = filename:join(code:lib_dir(debugger), "ebin"),
code:unstick_dir(EbinDir),
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%====================================================================
%% Internal functions
%%====================================================================
auto_attach(Why, Auto, #proc{attpid = Attpid, pid = Pid}) ->
case Attpid of
undefined -> auto_attach(Why, Auto, Pid);
_ when is_pid(Attpid) -> ignore
end;
auto_attach(Why, Auto, Pid) when is_pid(Pid) ->
case Auto of
false -> ignore;
{Flags, {Mod, Func, Args}} ->
case lists:member(Why, Flags) of
true ->
spawn(Mod, Func, [Pid | Args]);
false -> ignore
end
end.
keyinsert(Tuple1, N, [Tuple2|Tuples]) ->
if
element(N, Tuple1) < element(N, Tuple2) ->
[Tuple1, Tuple2|Tuples];
true ->
[Tuple2 | keyinsert(Tuple1, N, Tuples)]
end;
keyinsert(Tuple, _N, []) ->
[Tuple].
list_setelement(N, L, E) -> list_setelement(1, N, L, E).
list_setelement(I, I, [_|T], E) ->
[E|T];
list_setelement(I, N, [H|T], E) ->
[H|list_setelement(I+1, N, T, E)].
mapfilter(Fun, [H|T]) ->
case Fun(H) of
ignore -> mapfilter(Fun, T);
H2 -> [H2|mapfilter(Fun, T)]
end;
mapfilter(_Fun, []) ->
[].
send_all([Type|Types], Msg, State) ->
send_all(Type, Msg, State),
send_all(Types, Msg, State);
send_all([], _Msg, _State) -> ok;
send_all(subscriber, Msg, State) ->
send_all(State#state.subs, Msg);
send_all(meta, Msg, State) ->
Metas = [Proc#proc.meta || Proc <- State#state.procs],
send_all(Metas, Msg);
send_all(attached, Msg, State) ->
AttPids= mapfilter(fun(Proc) ->
case Proc#proc.attpid of
Pid when is_pid(Pid) -> Pid;
undefined -> ignore
end
end,
State#state.procs),
send_all(AttPids, Msg).
send_all(Pids, Msg) ->
lists:foreach(fun(Pid) -> send(Pid, Msg) end, Pids).
send(Pid, Msg) ->
Pid ! {int, Msg}.
get_proc({Type, Pid}, Procs) ->
Index = case Type of
pid -> #proc.pid;
meta -> #proc.meta;
attpid -> #proc.attpid
end,
case lists:keyfind(Pid, Index, Procs) of
false -> false;
Proc -> {true, Proc}
end.
