aboutsummaryrefslogblamecommitdiffstats
path: root/lib/observer/src/ttb.erl
blob: f52b4f33faa1b0e573e7d9f74ee6ff917cca0bed (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461












































































































































































































































































































































































































































































                                                                                         







                                              

                  

                                                                   
                                          


                                                                     





                                            










                                                                          





















































































                                                                                 

                                                       



                                      
                                                












                                                                 
                                     


                                                               





                                                                         
                










                                                                                









                                                        




























































































































































































































































                                                                                
                                                   


































                                                                               
                                                   





































































































                                                                                
%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 2002-2009. All Rights Reserved.
%% 
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%% 
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%% 
%% %CopyrightEnd%
%%
-module(ttb).
-author('[email protected]').

%% API
-export([tracer/0,tracer/1,tracer/2,p/2,stop/0,stop/1]).
-export([tp/2, tp/3, tp/4, ctp/0, ctp/1, ctp/2, ctp/3, tpl/2, tpl/3, tpl/4, 
	 ctpl/0, ctpl/1, ctpl/2, ctpl/3, ctpg/0, ctpg/1, ctpg/2, ctpg/3]).
-export([seq_trigger_ms/0,seq_trigger_ms/1]).
-export([write_trace_info/2]).
-export([write_config/2,write_config/3,run_config/1,run_config/2,list_config/1]).
-export([list_history/0,run_history/1]).
-export([format/1,format/2]).

%% For debugging
-export([dump_ti/1]).

-include_lib("kernel/include/file.hrl").
-define(meta_time,5000).
-define(history_table,ttb_history_table).
-define(seq_trace_flags,[send,'receive',print,timestamp]).
-define(upload_dir,"ttb_upload").
-ifdef(debug).
-define(get_status,;get_status -> erlang:display(dict:to_list(NodeInfo)),loop(NodeInfo)).
-else.
-define(get_status,).
-endif.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Open a trace port on all given nodes and create the meta data file
tracer() -> tracer(node()).
tracer(Nodes) -> tracer(Nodes,[]).
tracer(Nodes,Opt) ->
    start(),
    store(tracer,[Nodes,Opt]),
    {PI,Client,Traci} = opt(Opt),
    do_tracer(Nodes,PI,Client,Traci).

do_tracer(Nodes0,PI,Client,Traci) ->
    Nodes = nods(Nodes0),
    Clients = clients(Nodes,Client),
    do_tracer(Clients,PI,Traci).

do_tracer(Clients,PI,Traci) ->
    {ClientSucc,Succ} = 
	lists:foldl(
	  fun({N,{local,File},TF},{CS,S}) -> 
		  [_Sname,Host] = string:tokens(atom_to_list(N),"@"),
		  case catch dbg:tracer(N,port,dbg:trace_port(ip,0)) of
		      {ok,N} ->
			  {ok,Port} = dbg:trace_port_control(N,get_listen_port),
			  {ok,T} = dbg:get_tracer(N),
			  rpc:call(N,seq_trace,set_system_tracer,[T]),
			  dbg:trace_client(ip,{Host,Port},
					   {fun ip_to_file/2,{file,File}}),
			  {[{N,{local,File,Port},TF}|CS], [N|S]};
		      Other ->
			  display_warning(N,{cannot_open_ip_trace_port,
					     Host,
					     Other}),
			  {CS, S}
		     end;
	     ({N,C,_}=Client,{CS,S}) -> 
		  case catch dbg:tracer(N,port,dbg:trace_port(file,C)) of
		      {ok,N} -> 
			  {ok,T} = dbg:get_tracer(N),
			  rpc:call(N,seq_trace,set_system_tracer,[T]),
			  {[Client|CS], [N|S]};
		      Other -> 
			  display_warning(N,Other),
			  {CS,S}
		  end
	  end, 
	  {[],[]}, 
	  Clients),
    case Succ of
	[] -> 
	    {ok,Succ};
	_list ->
	    write_info(ClientSucc,PI,Traci),
	    {ok,Succ}
    end.

opt(Opt) ->
    opt(Opt,{true,?MODULE,[]}).

opt([{process_info,PI}|O],{_,Client,Traci}) ->
    opt(O,{PI,Client,Traci});
opt([{file,Client}|O],{PI,_,Traci}) ->
    opt(O,{PI,Client,Traci});
opt([{handler,Handler}|O],{PI,Client,Traci}) ->
    opt(O,{PI,Client,[{handler,Handler}|Traci]});
opt([],Opt) ->
    Opt.

nods(all) ->
    Nodes1 = remove_active([node()|nodes()]),
    remove_faulty_runtime_tools_vsn(Nodes1);
nods(Node) when is_atom(Node) ->
    nods([Node]);
nods(Nodes) when is_list(Nodes) ->
    Nodes1 = remove_active(Nodes),
    Nodes2 = remove_noexist(Nodes1),
    remove_faulty_runtime_tools_vsn(Nodes2).

remove_active(Nodes) ->
    Active = get_nodes(),
    lists:filter(
      fun(N) -> case lists:member(N,Active) of
		    false -> true;
		    true -> display_warning(N,already_started), false
		end
      end, Nodes).

remove_noexist(Nodes) ->
    lists:filter(
      fun(N) when N=:=node() ->
	      true;
	 (N) ->
	      case net_adm:ping(N) of
		  pong -> true;
		  pang -> display_warning(N,no_connection), false
	      end
      end, Nodes).

remove_faulty_runtime_tools_vsn(Nodes) ->
    lists:filter(
      fun(N) ->
	      case rpc:call(N,observer_backend,vsn,[]) of
		  {ok,Vsn} -> check_vsn(N,Vsn);
		  _Error -> display_warning(N,faulty_vsn_of_runtime_tools), false
	      end
      end,Nodes).

check_vsn(_Node,_Vsn) -> true.
%check_vsn(Node,_Vsn) -> 
%    display_warning(Node,faulty_vsn_of_runtime_tools),
%    false.

clients(Nodes, {wrap,Name}) ->
    F = fun(Node) -> 
		TraceFile = name(Node,Name),
		{Node,{TraceFile++".",wrap,".wrp"},TraceFile} 
	end,
    lists:map(F,Nodes);
clients(Nodes, {wrap,Name,Size,Count}) ->
    F = fun(Node) -> 
		TraceFile = name(Node,Name),
		{Node,{TraceFile++".",wrap,".wrp",Size,Count},TraceFile} 
	end,
    lists:map(F,Nodes);
clients(Nodes, {local,RealClient}) ->
    WrapClients = clients(Nodes,RealClient),
    F = fun({Node,Client,TraceFile}) -> 
		{Node,{local,Client},TraceFile}
	end,
    lists:map(F,WrapClients);
clients(Nodes, Name) ->
    F = fun(Node) -> 
		TraceFile = name(Node,Name),
		{Node,TraceFile,TraceFile}
	end,
    lists:map(F,Nodes).
    
name(Node,Filename) ->
    Dir = filename:dirname(Filename), 
    File = filename:basename(Filename),
    filename:join(Dir,atom_to_list(Node) ++ "-" ++ File).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Handling of config file
store(Func,Args) ->
    Last = case ets:last(?history_table) of
	       '$end_of_table' -> 0;
	       Int when is_integer(Int) -> Int
	   end,
    ets:insert(?history_table,{Last+1,{?MODULE,Func,Args}}).

list_history() -> 
    %% the check is only to see if the tool is started.
    case ets:info(?history_table) of
	undefined -> {error, not_running};
	_info -> ets:tab2list(?history_table)
    end.

run_history([H|T]) ->
    case run_history(H) of
	ok -> run_history(T);
	{error,not_found} -> {error,{not_found,H}}
    end;
run_history([]) ->
    ok;
run_history(N) ->
    case catch ets:lookup(?history_table,N) of
	[{N,{M,F,A}}] -> 
	    print_func(M,F,A),
	    R = apply(M,F,A),
	    print_result(R);
	_ -> 
	    {error, not_found}
    end.
	
write_config(ConfigFile,all) ->
    write_config(ConfigFile,['_']);
write_config(ConfigFile,Config) ->
    write_config(ConfigFile,Config,[]).
write_config(ConfigFile,all,Opt) ->
    write_config(ConfigFile,['_'],Opt);
write_config(ConfigFile,Nums,Opt) when is_list(Nums), is_integer(hd(Nums)); 
				       Nums=:=['_'] ->
    F = fun(N) -> ets:select(?history_table,
			     [{{N,'$1'},[],['$1']}])
	end,
    Config = lists:append(lists:map(F,Nums)),
    do_write_config(ConfigFile,Config,Opt);
write_config(ConfigFile,Config,Opt) when is_list(Config) ->
    case check_config(Config,[]) of
	{ok,Config1} -> do_write_config(ConfigFile,Config1,Opt);
	Error -> Error
    end.

do_write_config(ConfigFile,Config,Opt) ->
    case Opt of
	[append] -> ok;
        [] -> file:delete(ConfigFile)
    end,
    write_binary(ConfigFile,Config).

check_config([{?MODULE=Mod,Func,Args}|Rest],Acc) ->
    %% Check only in this module, since other modules might not
    %% be loaded at the time of creating the config file.
    case erlang:function_exported(Mod,Func,length(Args)) of
	true -> check_config(Rest,[{Mod,Func,Args}|Acc]);
	false -> {error, {not_exported,{Mod,Func,Args}}}
    end;
check_config([{Mod,Func,Args}|Rest],Acc) ->
    check_config(Rest,[{Mod,Func,Args}|Acc]);
check_config([],Acc) ->
    {ok,lists:reverse(Acc)};
check_config([Other|_Rest],_Acc) ->
    {error,{illegal_config,Other}}.


list_config(ConfigFile) ->
    case file:read_file(ConfigFile) of
	{ok,B} -> read_config(B,[],1);
	Error -> Error
    end.
    
read_config(<<>>,Acc,_N) ->
    lists:reverse(Acc);
read_config(B,Acc,N) ->
    {{M,F,A},Rest} = get_term(B),
    read_config(Rest,[{N,{M,F,A}}|Acc],N+1).


run_config(ConfigFile) ->
    case list_config(ConfigFile) of
	Config when is_list(Config) ->
	    lists:foreach(fun({_,{M,F,A}}) -> print_func(M,F,A),
					      R = apply(M,F,A),
					      print_result(R) 
			  end,
			  Config);
	Error -> Error
    end.

run_config(ConfigFile,N) ->
    case list_config(ConfigFile) of
	Config when is_list(Config) ->
	    case lists:keysearch(N,1,Config) of
		{value,{N,{M,F,A}}} -> 
		    print_func(M,F,A),
		    apply(M,F,A);
		false -> 
		    {error, not_found}
	    end;
	Error -> Error
    end.
    
    
print_func(M,F,A) ->
    Args = arg_list(A,[]),
    io:format("~w:~w(~s) ->~n",[M,F,Args]).
print_result(R) ->
    io:format("~p~n~n",[R]).

arg_list([],[]) ->
    "";
arg_list([A1],Acc) ->
    Acc++io_lib:format("~w",[A1]);
arg_list([A1|A],Acc) ->
    arg_list(A,Acc++io_lib:format("~w,",[A1])).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Set trace flags on processes
p(Procs0,Flags0) ->
    store(p,[Procs0,Flags0]),
    no_store_p(Procs0,Flags0).
no_store_p(Procs0,Flags0) ->
    case transform_flags(to_list(Flags0)) of
	{error,Reason} -> 
	    {error,Reason};
	Flags ->
	    Procs = procs(Procs0),
	    case lists:foldl(fun(P,{PMatched,Ps}) -> case dbg:p(P,Flags) of
					     {ok,Matched} -> 
						 {[{P,Matched}|PMatched],[P|Ps]};
					     {error,Reason} -> 
						 display_warning(P,Reason),
						 {PMatched,Ps}
					 end
			     end,{[],[]},Procs) of
		{[],[]} -> {error, no_match};
		{SuccMatched,Succ} ->
		    no_store_write_trace_info(flags,{Succ,Flags}),
		    {ok,SuccMatched}
	    end
    end.

transform_flags([clear]) ->
    [clear];
transform_flags(Flags) ->
    dbg:transform_flags(Flags).


procs(Procs) when is_list(Procs) ->
    lists:foldl(fun(P,Acc) -> proc(P)++Acc end,[],Procs);
procs(Proc) ->
    proc(Proc).

proc(Procs) when Procs=:=all; Procs=:=existing; Procs=:=new ->
    [Procs];
proc(Name) when is_atom(Name) ->
    [Name]; % can be registered on this node or other node
proc(Pid) when is_pid(Pid) ->
    [Pid];
proc({global,Name}) ->
    case global:whereis_name(Name) of
	Pid when is_pid(Pid) ->
	    [Pid];
	undefined ->
	    []
    end.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Trace pattern
tp(A,B) ->
    store(tp,[A,B]),
    dbg:tp(A,B).
tp(A,B,C) ->
    store(tp,[A,B,C]),
    dbg:tp(A,B,C).
tp(A,B,C,D) ->
    store(tp,[A,B,C,D]),
    dbg:tp(A,B,C,D).

tpl(A,B) ->
    store(tpl,[A,B]),
    dbg:tpl(A,B).
tpl(A,B,C) ->
    store(tpl,[A,B,C]),
    dbg:tpl(A,B,C).
tpl(A,B,C,D) ->
    store(tpl,[A,B,C,D]),
    dbg:tpl(A,B,C,D).

ctp() ->
    store(ctp,[]),
    dbg:ctp().
ctp(A) ->
    store(ctp,[A]),
    dbg:ctp(A).
ctp(A,B) ->
    store(ctp,[A,B]),
    dbg:ctp(A,B).
ctp(A,B,C) ->
    store(ctp,[A,B,C]),
    dbg:ctp(A,B,C).

ctpl() ->
    store(ctpl,[]),
    dbg:ctpl().
ctpl(A) ->
    store(ctpl,[A]),
    dbg:ctpl(A).
ctpl(A,B) ->
    store(ctpl,[A,B]),
    dbg:ctpl(A,B).
ctpl(A,B,C) ->
    store(ctpl,[A,B,C]),
    dbg:ctpl(A,B,C).

ctpg() ->
    store(ctpg,[]),
    dbg:ctpg().
ctpg(A) ->
    store(ctpg,[A]),
    dbg:ctpg(A).
ctpg(A,B) ->
    store(ctpg,[A,B]),
    dbg:ctpg(A,B).
ctpg(A,B,C) ->
    store(ctpg,[A,B,C]),
    dbg:ctpg(A,B,C).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Support for sequential trace
seq_trigger_ms() -> seq_trigger_ms(all).
seq_trigger_ms(all) -> seq_trigger_ms(?seq_trace_flags);
seq_trigger_ms(Flag) when is_atom(Flag) -> seq_trigger_ms([Flag],[]);
seq_trigger_ms(Flags) -> seq_trigger_ms(Flags,[]).
seq_trigger_ms([Flag|Flags],Body) ->
    case lists:member(Flag,?seq_trace_flags) of
	true -> seq_trigger_ms(Flags,[{set_seq_token,Flag,true}|Body]);
	false -> {error,{illegal_flag,Flag}}
    end;
seq_trigger_ms([],Body) ->
    [{'_',[],Body}].


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Write information to the .ti file
write_trace_info(Key,What) ->
    store(write_trace_info,[Key,What]),
    no_store_write_trace_info(Key,What).

no_store_write_trace_info(Key,What) ->
    case whereis(?MODULE) of
	undefined -> ok;
	Pid when is_pid(Pid) -> ?MODULE ! {write_trace_info,Key,What}
    end,
    ok.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Stop tracing on all nodes
stop() ->
    stop([]).
stop(Opts) ->
    Fetch = stop_opts(Opts),
    Result =
        case whereis(?MODULE) of
            undefined -> ok;
            Pid when is_pid(Pid) ->
                ?MODULE ! {stop,Fetch,self()},
                receive {?MODULE,R} -> R end
        end,
    stop_return(Result,Opts).

stop_opts(Opts) ->
    case {lists:member(format,Opts), lists:member(return, Opts)} of
	{true, _} ->
	    format; % format implies fetch
	{_, true} ->
	    fetch; % if we specify return, the data should be fetched
	_ ->
	    case lists:member(fetch,Opts) of
		true -> fetch;
		false -> nofetch
	    end
    end.

stop_return(R,Opts) ->
    case {lists:member(return,Opts),R} of
        {true,_} ->
            R;
        {false,{stopped,_}} ->
            stopped;
        {false,_} ->
            %% Anything other than 'stopped' would not be bw compatible...
            stopped
    end.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Process implementation
start() ->
    case whereis(?MODULE) of
	undefined ->
	    Parent = self(),
	    Pid = spawn(fun() -> init(Parent) end),
	    receive {started,Pid} -> ok end;
	Pid when is_pid(Pid) ->
	    ok
    end.


init(Parent) ->
    register(?MODULE,self()),
    ets:new(?history_table,[ordered_set,named_table,public]),
    Parent ! {started,self()},
    loop(dict:new()).

loop(NodeInfo) ->
    receive 
	{init_node,Node,MetaFile,PI,Traci} ->
	    erlang:monitor_node(Node,true),
	    MetaPid = 
		case rpc:call(Node,
			      observer_backend,
			      ttb_init_node,
			      [MetaFile,PI,Traci]) of
		    {ok,MP} ->
			MP;
		    {badrpc,nodedown} ->
			%% We will get a nodedown message
			undefined
		end,
	    loop(dict:store(Node,{MetaFile,MetaPid},NodeInfo));
	{get_nodes,Sender} ->
	    Sender ! {?MODULE,dict:fetch_keys(NodeInfo)},
	    loop(NodeInfo);
	{write_trace_info,Key,What} ->
	    dict:fold(fun(Node,{_MetaFile,MetaPid},_) -> 
			      rpc:call(Node,observer_backend,
				       ttb_write_trace_info,[MetaPid,Key,What])
		      end,
		      ok,
		      NodeInfo),
	    loop(NodeInfo);
	{nodedown,Node} ->
	    loop(dict:erase(Node,NodeInfo));
	{stop,nofetch,Sender} ->
	    dict:fold(
	      fun(Node,{_,MetaPid},_) -> 
		      rpc:call(Node,observer_backend,ttb_stop,[MetaPid])
	      end,
	      ok,
	      NodeInfo),
	    dbg:stop_clear(),
	    ets:delete(?history_table),
	    Sender ! {?MODULE,stopped};
	{stop,FetchOrFormat,Sender} ->
	    Localhost = host(node()),
	    Dir = ?upload_dir++ts(),
 	    file:make_dir(Dir),
	    %% The nodes are traversed twice here because
	    %% the meta tracing in observer_backend must be
	    %% stopped before dbg is stopped, and dbg must
	    %% be stopped before the trace logs are moved orelse
	    %% windows complains.
	    AllNodesAndMeta = 
		dict:fold(
		  fun(Node,{MetaFile,MetaPid},Nodes) -> 
			  rpc:call(Node,observer_backend,ttb_stop,[MetaPid]),
			  [{Node,MetaFile}|Nodes]
		  end,
		  [],
		  NodeInfo),
	    dbg:stop_clear(),
	    AllNodes = 
		lists:map(
		  fun({Node,MetaFile}) ->
			  spawn(fun() -> fetch(Localhost,Dir,Node,MetaFile) end),
			  Node
		  end,
		  AllNodesAndMeta),
	    ets:delete(?history_table),
	    wait_for_fetch(AllNodes),
            Absname = filename:absname(Dir),
	    io:format("Stored logs in ~s~n",[Absname]),
	    case FetchOrFormat of
		format -> format(Dir);
		fetch -> ok
	    end,
	    Sender ! {?MODULE,{stopped,Absname}}
         ?get_status
    end.

get_nodes() ->
    ?MODULE ! {get_nodes,self()},
    receive {?MODULE,Nodes} -> Nodes end.

ts() ->
    {{Y,M,D},{H,Min,S}} = calendar:now_to_local_time(now()),
    io_lib:format("-~4.4.0w~2.2.0w~2.2.0w-~2.2.0w~2.2.0w~2.2.0w",
		  [Y,M,D,H,Min,S]).


fetch(Localhost,Dir,Node,MetaFile) ->
    case (host(Node) == Localhost) orelse is_local(MetaFile) of
        true -> % same host, just move the files
	    Files = get_filenames(Node,MetaFile),
	    lists:foreach(
	      fun(File0) ->
		      File = filename:join(Dir,filename:basename(File0)),
		      file:rename(File0,File)
	      end,
	      Files);
	false ->
	    {ok, LSock} = gen_tcp:listen(0, [binary,{packet,2},{active,false}]),
	    {ok,Port} = inet:port(LSock),
	    rpc:cast(Node,observer_backend,ttb_fetch,
		     [MetaFile,{Port,Localhost}]),
	    {ok, Sock} = gen_tcp:accept(LSock),
	    receive_files(Dir,Sock,undefined),
	    ok = gen_tcp:close(LSock),
	    ok = gen_tcp:close(Sock)
    end,
    ?MODULE ! {fetch_complete,Node}.

is_local({local, _, _}) ->
    true;
is_local(_) ->
    false.

get_filenames(_N, {local,F,_}) ->
    observer_backend:ttb_get_filenames(F);
get_filenames(N, F) ->
    rpc:call(N, observer_backend,ttb_get_filenames,[F]).

receive_files(Dir,Sock,Fd) ->
    case gen_tcp:recv(Sock, 0) of
	{ok, <<0,Bin/binary>>} ->
	    file:write(Fd,Bin),
	    receive_files(Dir,Sock,Fd);
	{ok, <<1,Bin/binary>>} ->
	    File0 = binary_to_list(Bin),
	    File = filename:join(Dir,File0),
	    {ok,Fd1} = file:open(File,[raw,write]),
	    receive_files(Dir,Sock,Fd1);
	{error, closed} ->
	    ok = file:close(Fd)
    end.    

host(Node) ->
    [_name,Host] = string:tokens(atom_to_list(Node),"@"),
    Host.


wait_for_fetch([]) ->
    ok;
wait_for_fetch(Nodes) ->
    receive 
	{fetch_complete,Node} ->
	    wait_for_fetch(lists:delete(Node,Nodes))
    end.

%%% - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
%%% TRACE INFORMATION FILE
%%% ======================
%%% The trace information file has the same name as the trace log,
%%% but with the extension ".ti". It contains process information,
%%% trace information and any data the user writes with the
%%% function write_trace_info/2.
%%%
%%% The file is read during formatting of trace logs, and all data
%%% except process information is included in the handler function.
%%% - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

write_info(Nodes,PI,Traci) ->
    lists:foreach(fun({N,{local,C,_},F}) -> 
			  MetaFile = F ++ ".ti",
			  file:delete(MetaFile),
			  Traci1 = [{node,N},{file,C}|Traci],
			  {ok,Port} = dbg:get_tracer(N),
			  ?MODULE ! 
			      {init_node, N, {local,MetaFile,Port}, PI, Traci1};
		     ({N,C,F}) -> 
			  MetaFile = F ++ ".ti",
			  Traci1 = [{node,N},{file,C}|Traci],
			  ?MODULE ! {init_node, N, MetaFile, PI, Traci1}
		  end,
		  Nodes).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Format binary trace logs
format(Files) ->
    format(Files,[]).
format(Files,Opt) ->
    {Out,Handler} = format_opt(Opt),
    ets:new(?MODULE,[named_table]),
    format(Files,Out,Handler).
format(File,Out,Handler) when is_list(File), is_integer(hd(File)) ->
    Files = 
	case filelib:is_dir(File) of
	    true ->  % will merge all files in the directory
		MetaFiles = filelib:wildcard(filename:join(File,"*.ti")),
		lists:map(fun(M) ->
				  Sub = string:left(M,length(M)-3),
				  case filelib:is_file(Sub) of
				      true -> Sub;
				      false -> Sub++".*.wrp"
				  end
			  end,
			  MetaFiles);
	    false -> % format one file
		[File]
	end,
    format(Files,Out,Handler);
format(Files,Out,Handler) when is_list(Files), is_list(hd(Files)) ->
    StopDbg = case whereis(dbg) of
		  undefined -> true;
		  _ -> false
	      end,
    Details = lists:foldl(fun(File,Acc) -> [prepare(File,Handler)|Acc] end,
			  [],Files),
    Fd = get_fd(Out),
    R = do_format(Fd,Details),
    file:close(Fd),
    ets:delete(?MODULE),
    case StopDbg of
	true -> dbg:stop_clear();
	false -> ok
    end,
    R.

prepare(File,Handler) ->
    {Traci,Proci} = read_traci(File),
    Node = get_node(Traci),
    lists:foreach(fun({Pid,PI}) ->
			  %% The last definition for a Pid will overwrite
			  %% any previous definitions. That should be what
			  %% we want (we will get the registered name for
			  %% the process, rather than the initial call if
			  %% both are present in the list).
			  ets:insert(?MODULE,{Pid,PI,Node})
		  end,Proci),
    FileOrWrap = get_file(File,Traci),
    Handler1 = get_handler(Handler,Traci),
    {FileOrWrap,Traci,Handler1}.

format_opt(Opt) ->
    Out = case lists:keysearch(out,1,Opt) of
	      {value,{out,O}} -> O;
	      _ -> standard_io
	  end,
    Handler = case lists:keysearch(handler,1,Opt) of
	      {value,{handler,H}} -> H;
	      _ -> undefined
	  end,
    {Out,Handler}.


read_traci(File) ->
    MetaFile = get_metafile(File),
    case file:read_file(MetaFile) of
	{ok,B} -> 
	    interpret_binary(B,dict:new(),[]);
	_ -> 
	    io:format("Warning: no meta data file: ~s~n",[MetaFile]),
	    {dict:new(),[]}
    end.

get_metafile(File) ->
    case filename:rootname(File,".wrp") of
	File -> File++".ti";
	Wrap -> filename:rootname(Wrap)++".ti"
    end.


interpret_binary(<<>>,Dict,P) ->
    {Dict,lists:reverse(P)};
interpret_binary(B,Dict,P) ->
    {Term,Rest} = get_term(B),
    {Dict1,P1} = 
	case Term of
	    {pid,PI} ->
		{Dict,[PI|P]};
	    {Key,Val} ->
		{dict:update(Key,fun(Val0) -> [Val|Val0] end, [Val], Dict),P}
	end,
    interpret_binary(Rest,Dict1,P1).

get_fd(Out) ->
    case Out of
	standard_io ->
	    Out;
	_file ->
	    file:delete(Out),
	    case file:open(Out,[append]) of
		{ok,Fd} -> Fd;
		Error -> exit(Error)
	    end
    end.

get_node(Traci) ->
    case dict:find(node,Traci) of
	{ok,[Node]} -> Node;
	error -> unknown
    end.

get_file(File,Traci) ->
    case dict:find(file,Traci) of
	{ok,[Client]} ->
	    check_client(Client,File);
	error ->
	    check_exists(File)
    end.

check_client(Client,File) when is_list(Client) ->
    check_exists(File);
check_client(Client,File) when is_tuple(Client),element(2,Client)==wrap ->
    Root = filename:rootname(File,".wrp"),
    case filename:extension(Root) of
	".*" -> 
	    Part1 = filename:rootname(Root,"*"),
	    setelement(1,Client,Part1);
	_ -> 
	    check_exists(File)
    end.

check_exists(File) ->
    case file:read_file_info(File) of
	{ok,#file_info{type=regular}} -> File;
	_ -> 
	    exit({error,no_file})
    end.
	

get_handler(Handler,Traci) ->
    case Handler of
	undefined -> 
	    case dict:find(handler,Traci) of
		{ok,[H]} -> H;
		error -> undefined
	    end;
	_ ->
	    Handler
    end.

do_format(Fd,Details) ->
    Clients = lists:foldl(fun({FileOrWrap,Traci,Handler},Acc) ->
				  [start_client(FileOrWrap,Traci,Handler)
				   |Acc]
			  end,[],Details),
    init_collector(Fd,Clients).


start_client(FileOrWrap,Traci,et) ->
    dbg:trace_client(file, FileOrWrap, 
		     {fun handler/2, 
		      {dict:to_list(Traci),{{ttb_et,handler},initial}}});
start_client(FileOrWrap,Traci,undefined) ->
    dbg:trace_client(file, FileOrWrap, 
		     {fun handler/2, 
		      {dict:to_list(Traci),{fun defaulthandler/4,initial}}});
start_client(FileOrWrap,Traci,Handler) ->
    dbg:trace_client(file, FileOrWrap, 
		     {fun handler/2, {dict:to_list(Traci),Handler}}).

handler(Trace,State) ->
    %% State here is only used for the initial state. The accumulated
    %% State is maintained by collector!!!
    receive 
	{get,Collector} -> Collector ! {self(),{Trace,State}};
	done -> ok
    end,
    State.

handler1(Trace,{Fd,{Traci,{Fun,State}}}) when is_function(Fun) ->
    {Traci,{Fun,Fun(Fd,Trace,Traci,State)}};
handler1(Trace,{Fd,{Traci,{{M,F},State}}}) when is_atom(M), is_atom(F) ->
    {Traci,{{M,F},M:F(Fd,Trace,Traci,State)}}.

defaulthandler(Fd,Trace,_Traci,initial) ->
    dbg:dhandler(Trace,Fd);
defaulthandler(_Fd,Trace,_Traci,State) ->
    dbg:dhandler(Trace,State).

init_collector(Fd,Clients) ->
    Collected = get_first(Clients),
    collector(Fd,sort(Collected)).

collector(Fd,[{_,{Client,{Trace,State}}} |Rest]) ->
    Trace1 = update_procinfo(Trace),
    State1 = handler1(Trace1,{Fd,State}),
    case get_next(Client,State1) of
	end_of_trace -> 
	    handler1(end_of_trace,{Fd,State1}),
	    collector(Fd,Rest);
	Next -> collector(Fd,sort([Next|Rest]))
    end;
collector(_Fd,[]) ->
    ok.

update_procinfo({drop,_N}=Trace) ->
    Trace;
update_procinfo(Trace) when element(1,Trace)==seq_trace ->
    Info = element(3,Trace),
    Info1 = 
	case Info of
	    {send, Serial, From, To, Msg} ->
		{send, Serial, get_procinfo(From), get_procinfo(To), Msg};
	    {'receive', Serial, From, To, Msg} ->
		{'receive', Serial, get_procinfo(From), get_procinfo(To), Msg};
	    {print, Serial, From, Void, UserInfo} ->
		{print, Serial, get_procinfo(From), Void, UserInfo};
	    Other ->
		Other
	end,
    setelement(3,Trace,Info1);
update_procinfo(Trace) when element(3,Trace)==send ->
    PI = get_procinfo(element(5,Trace)),
    setelement(5,Trace,PI);
update_procinfo(Trace) ->
    Pid = element(2,Trace),
    ProcInfo = get_procinfo(Pid),
    setelement(2,Trace,ProcInfo).

get_procinfo(Pid) when is_pid(Pid); is_port(Pid) ->
    case ets:lookup(?MODULE,Pid) of
	[PI] -> PI;
	[] -> Pid
    end;
get_procinfo(Name) when is_atom(Name) ->
    case ets:match_object(?MODULE,{'_',Name,node()}) of
	[PI] -> PI;
	[] -> Name
    end;
get_procinfo({Name,Node}) when is_atom(Name) ->
    case ets:match_object(?MODULE,{'_',Name,Node}) of
	[PI] -> PI;
	[] -> {Name,Node}
    end.	 

get_first([Client|Clients]) ->
    Client ! {get,self()},
    receive 
	{Client,{end_of_trace,_}} -> 
	    get_first(Clients);
	{Client,{Trace,_State}}=Next -> 
	    [{timestamp(Trace),Next}|get_first(Clients)]
    end;
get_first([]) -> [].

get_next(Client,State) when is_pid(Client) ->
    Client ! {get,self()},
    receive 
	{Client,{end_of_trace,_}} -> 
	    end_of_trace;
	{Client,{Trace,_OldState}} -> 
	    {timestamp(Trace),{Client,{Trace,State}}} % inserting new state!!
    end.

sort(List) ->
    lists:keysort(1,List).


timestamp(Trace) when element(1,Trace) =:= trace_ts;
		      element(1,Trace) =:= seq_trace, tuple_size(Trace) =:= 4 ->
    element(tuple_size(Trace),Trace);
timestamp(_Trace) ->
    0.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% common internal functions
to_list(Atom) when is_atom(Atom) -> [Atom];
to_list(List) when is_list(List) -> List.

write_binary(File,TermList) ->
    {ok,Fd} = file:open(File,[raw,append]),    
    %% Using the function implemented in observer_backend, only because
    %% is exists - so I don't have to write the same code twice.
    observer_backend:ttb_write_binary(Fd,TermList),
    file:close(Fd).

get_term(B) ->
    <<S:8, B2/binary>> = B,
    <<T:S/binary, Rest/binary>> = B2,
    case binary_to_term(T) of
	{'$size',Sz} -> 
	    %% size of the actual term was bigger than 8 bits
	    <<T1:Sz/binary, Rest1/binary>> = Rest,
	    {binary_to_term(T1),Rest1};
	Term ->
	    {Term,Rest}
    end.

display_warning(Item,Warning) ->
    io:format("Warning: {~w,~w}~n",[Warning,Item]).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Trace client which reads an IP port and puts data directly to a file.
%%% This is used when tracing remote nodes with no file system.
ip_to_file(Trace,{file,File}) ->
    Fun = dbg:trace_port(file,File), %File can be a filename or a wrap spec
    Port = Fun(),
    ip_to_file(Trace,Port);
ip_to_file({metadata,MetaFile,MetaData},Port) ->
    {ok,MetaFd} = file:open(MetaFile,[write,raw,append]),
    file:write(MetaFd,MetaData),
    file:close(MetaFd),
    Port;
ip_to_file(Trace,Port) ->
    B = term_to_binary(Trace),
    erlang:port_command(Port,B),
    Port.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% For debugging
dump_ti(File) ->
    {ok,B} = file:read_file(File),
    dump_ti(B,[]).

dump_ti(<<>>,Acc) ->
    lists:reverse(Acc);
dump_ti(B,Acc) ->
    {Term,Rest} = get_term(B),
    dump_ti(Rest,[Term|Acc]).