summaryrefslogtreecommitdiffstats
path: root/src/xua_as_fsm.erl
blob: 9380f8e03561d85d2deb0ad5b91b739bda332610 (plain)
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
% M2UA / M3UA / SUA AS gsn_fsm according to RFC3868 4.3.1

% (C) 2011-2012 by Harald Welte <laforge@gnumonks.org>
%
% All Rights Reserved
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU Affero General Public License as
% published by the Free Software Foundation; either version 3 of the
% License, or (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU Affero General Public License
% along with this program.  If not, see <http://www.gnu.org/licenses/>.
%
% Additional Permission under GNU AGPL version 3 section 7:
%
% If you modify this Program, or any covered work, by linking or
% combining it with runtime libraries of Erlang/OTP as released by
% Ericsson on http://www.erlang.org (or a modified version of these
% libraries), containing parts covered by the terms of the Erlang Public
% License (http://www.erlang.org/EPLICENSE), the licensors of this
% Program grant you additional permission to convey the resulting work
% without the need to license the runtime libraries of Erlang/OTP under
% the GNU Affero General Public License. Corresponding Source for a
% non-source form of such a combination shall include the source code
% for the parts of the runtime libraries of Erlang/OTP used as well as
% that of the covered work.

-module(xua_as_fsm).
-author('Harald Welte <laforge@gnumonks.org>').
-behaviour(gen_fsm).

-include("osmo_util.hrl").
-include("m3ua.hrl").

% gen_fsm exports
-export([init/1, terminate/3, code_change/4, handle_event/3, handle_sync_event/4, handle_info/3]).

% states in this FSM
-export([as_down/2, as_inactive/2, as_active/2, as_pending/2]).

% exported API
-export([create_asp/2]).

% Timeouts in milliseconds
-define(T_R_TIMEOUT, 2*60*100).

-record(as_state, {
		as_sup_pid,
		role,
		t_r,
		asp_list
	}).

create_asp(Name, AspFsmArgs) ->
	AsFsmName = sg_as_sup:get_as_fsm_name(Name),
	gen_fsm:sync_send_all_state_event(AsFsmName, {create_asp, AspFsmArgs}).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% gen_fsm callbacks
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

init([AsSupPid]) when is_pid(AsSupPid) ->
	AsState = #as_state{asp_list = [],
			    as_sup_pid = AsSupPid,
			    role = sg},
	{ok, as_down, AsState}.

terminate(Reason, State, _LoopDat) ->
	io:format("Terminating ~p in State ~p (Reason: ~p)~n",
		  [?MODULE, State, Reason]),
	ok.

code_change(_OldVsn, StateName, LoopDat, _Extra) ->
	{ok, StateName, LoopDat}.

handle_sync_event({create_asp, Args}, From, State, LoopDat) ->
	% resolve the ASP supervisor PID
	AsSupPid = LoopDat#as_state.as_sup_pid,
	AsChildList = supervisor:which_children(AsSupPid),
	io:format("AsSupPid ~p, ChildList ~p~n", [AsSupPid, AsChildList]),
	{asp_sup, AspSupPid, _, _} = lists:keyfind(asp_sup, 1, AsChildList),
	% actually tell it to start a new ASP, prepend our own Pid
	Ret = supervisor:start_child(AspSupPid, [self()|Args]),
	LoopDatOut = case Ret of
		{ok, AspPid} ->
			link(AspPid),
			LoopDat#as_state{asp_list = [AspPid|LoopDat#as_state.asp_list]};
		{ok, AspPid, _} ->
			link(AspPid),
			LoopDat#as_state{asp_list = [AspPid|LoopDat#as_state.asp_list]};
		_ ->
			LoopDat
	end,
	{reply, Ret, State, LoopDatOut}.

handle_event(Event, State, LoopDat) ->
	io:format("Unknown Event ~p in state ~p~n", [Event, State]),
	{next_state, State, LoopDat}.

handle_info({'EXIT', Pid, Reason}, State, LoopDat) ->
	io:format("EXIT from Process ~p (~p), cleaning up ASP list~n",
		  [Pid, Reason]),
	% FIXME: send fake ASP-DOWN event about ASP to self
	NewAspList = lists:delete(Pid, LoopDat#as_state.asp_list),
	{next_state, State, LoopDat#as_state{asp_list = NewAspList}};

handle_info(Info, State, LoopDat) ->
	io:format("Unknown Info ~p in state ~p~n", [Info, State]),
	{next_state, State, LoopDat}.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% STATE "as_down"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

as_down(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
		   spec_name = indication, parameters = _Params}, LoopDat) ->
	% One ASP transitions into ASP-INACTIVE
	next_state(as_inactive, LoopDat);

as_down(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_DOWN',
		   spec_name = indication, parameters = _Params}, LoopDat) ->
	% ignore
	next_state(as_down, LoopDat).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% STATE "as_inactive"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_DOWN',
			spec_name = indication, parameters = AsPid}, LoopDat) ->
	% One ASP transitions into ASP-DOWN
	% FIXME: check if there are any other ASP != DOWN, if yes -> as_inactive
	case check_any_other_asp_not_down(LoopDat, AsPid) of
		true ->
			next_state(as_inactive, LoopDat);
		false ->
			next_state(as_down, LoopDat)
	end;

as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
			spec_name = indication, parameters = Params}, LoopDat) ->
	% One ASP transitions to ASP-ACTIVE
	next_state(as_active, LoopDat);

as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
		       spec_name = indication, parameters = _Params}, LoopDat) ->
	% ignore
	next_state(as_inactive, LoopDat).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% STATE "as_active"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

as_active(#primitive{subsystem = 'ASPAS', gen_name = InactDown,
		     spec_name = indication, parameters = AspPid}, LoopDat) when
		InactDown == 'ASP_DOWN'; InactDown == 'ASP_INACTIVE' ->
	% One ASP transitions to ASP-INACTIVE
	% check if there are other ASP in active, if yes -> as_active
	case check_any_other_asp_in_active(LoopDat, AspPid) of
		true ->
			next_state(as_active, LoopDat);
		false ->
			{ok, Tr} = timer:apply_after(?T_R_TIMEOUT, gen_fsm, send_event,
						 [self(), {timer_expired, t_r}]),
			next_state(as_pending, LoopDat#as_state{t_r = Tr})
	end;

as_active(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
		     spec_name = indication, parameters = _Params}, LoopDat) ->
	% ignore
	next_state(as_active, LoopDat).


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% STATE "as_pending"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

as_pending(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
		      spec_name = indication}, LoopDat) ->
	% One ASP transitions into ASP-ACTIVE
	timer:cancel(LoopDat#as_state.t_r),
	next_state(as_active, LoopDat);

as_pending(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
		      spec_name = indication, parameters = _Params}, LoopDat) ->
	% ignore
	next_state(as_pending, LoopDat);

% FIXME: do we need to re-check as_pending state if we get ASP_DOWN of the last
% inactive ASP ?
as_pending(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_DOWN',
		      spec_name = indication, parameters = _Params}, LoopDat) ->
	next_state(as_pending, LoopDat);

as_pending({timer_expired, t_r}, LoopDat) ->
	% check if there is at least one ASP in ASP-INACTIVE -> AS-INACTIVE
	case check_any_other_asp_in_inactive(LoopDat, undefined) of
		true ->
			next_state(as_inactive, LoopDat);
		false ->
			next_state(as_down, LoopDat)
	end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% helper functions
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

next_state(NewState, LoopDat) ->
	%FIXME Module:as_state_change(NewState, LoopDat#as_state.ext_state),
	{next_state, NewState, LoopDat}.

%create_asp(LoopDatIn = #as_state{asp_module = {AspModule, AspModuleArgs},
%				 asp_list = AspListIn}) ->
%	Args = [AspModule, AspModuleArgs, UserFun, UserFunArgs, SctpPid],
%	{ok, AspPid} = gen_fsm:start_link(xua_asp_fsm, Args, [{debug, [trace]}]),
%	{AspPid, LoopDatIn#{asp_list = [AspPid|AspListIn]}}.



check_any_other_asp_in_inactive(LoopDat, AspPid) ->
	check_any_other_asp_in_state('ASP_INACTIVE', LoopDat, AspPid).

check_any_other_asp_in_active(LoopDat, AspPid) ->
	check_any_other_asp_in_state('ASP_ACTIVE', LoopDat, AspPid).

check_any_other_asp_not_down(LoopDat, AspPid) ->
	ListWithoutMe = lists:delete(AspPid, LoopDat#as_state.asp_list),
	StateList = build_asp_state_list(ListWithoutMe),
	not lists:all(fun(E) -> E == 'ASP_DOWN' end, StateList).

check_any_other_asp_in_state(State, LoopDat, AspPid) ->
	ListWithoutMe = lists:delete(AspPid, LoopDat#as_state.asp_list),
	StateList = build_asp_state_list(ListWithoutMe),
	lists:member(State, StateList).

build_asp_state_list(ListOfPids) ->
	[xua_asp_fsm:get_state(X) || X <- ListOfPids].