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-rw-r--r--lib/diameter/src/base/diameter_watchdog.erl89
1 files changed, 65 insertions, 24 deletions
diff --git a/lib/diameter/src/base/diameter_watchdog.erl b/lib/diameter/src/base/diameter_watchdog.erl
index 53e659e3f6..eff5096745 100644
--- a/lib/diameter/src/base/diameter_watchdog.erl
+++ b/lib/diameter/src/base/diameter_watchdog.erl
@@ -49,8 +49,6 @@
-define(IS_NATURAL(N), (is_integer(N) andalso 0 =< N)).
--define(CHOOSE(B,T,F), if (B) -> T; true -> F end).
-
-record(config,
{suspect = 1 :: non_neg_integer(), %% OKAY -> SUSPECT
okay = 3 :: non_neg_integer()}). %% REOPEN -> OKAY
@@ -221,7 +219,6 @@ dict0(_, _, Acc) ->
Acc.
config_error(T) ->
- diameter_lib:error_report(configuration_error, T),
exit({shutdown, {configuration_error, T}}).
%% handle_call/3
@@ -270,7 +267,7 @@ event(Msg,
TPid = tpid(F,T),
E = {[TPid | data(Msg, TPid, From, To)], From, To},
send(Pid, {watchdog, self(), E}),
- ?LOG(transition, {self(), E}).
+ ?LOG(transition, {From, To}).
data(Msg, TPid, reopen, okay) ->
{recv, TPid, 'DWA', _Pkt} = Msg, %% assert
@@ -313,14 +310,13 @@ code_change(_, State, _) ->
%% The state transitions documented here are extracted from RFC 3539,
%% the commentary is ours.
-%% Service or watchdog is telling the watchdog of an accepting
-%% transport to die after connect_timer expiry or reestablished
-%% connection (in another transport process) respectively.
-transition(close, #watchdog{status = down}) ->
+%% Service is telling the watchdog of an accepting transport to die
+%% following transport death in state INITIAL, or after connect_timer
+%% expiry; or another watchdog is saying the same after reestablishing
+%% a connection previously had by this one.
+transition(close, #watchdog{}) ->
{{accept, _}, _, _} = getr(restart), %% assert
stop;
-transition(close, #watchdog{}) ->
- ok;
%% Service is asking for the peer to be taken down gracefully.
transition({shutdown, Pid, _}, #watchdog{parent = Pid,
@@ -332,6 +328,11 @@ transition({shutdown = T, Pid, Reason}, #watchdog{parent = Pid,
send(TPid, {T, self(), Reason}),
S#watchdog{shutdown = true};
+%% Transport is telling us that DPA has been sent in response to DPR:
+%% its death should lead to ours.
+transition({'DPR', TPid}, #watchdog{transport = TPid} = S) ->
+ S#watchdog{shutdown = true};
+
%% Parent process has died,
transition({'DOWN', _, process, Pid, _Reason},
#watchdog{parent = Pid}) ->
@@ -403,18 +404,39 @@ transition({open = Key, TPid, _Hosts, T},
%% REOPEN Connection down CloseConnection()
%% SetWatchdog() DOWN
+%% Transport has died after DPA or service requested termination ...
transition({'DOWN', _, process, TPid, _Reason},
#watchdog{transport = TPid,
shutdown = true}) ->
stop;
+%% ... or not.
transition({'DOWN', _, process, TPid, _Reason},
#watchdog{transport = TPid,
- status = T}
- = S) ->
- set_watchdog(S#watchdog{status = ?CHOOSE(initial == T, T, down),
- pending = false,
- transport = undefined});
+ status = T,
+ restrict = {_,R}}
+ = S0) ->
+ S = S0#watchdog{pending = false,
+ transport = undefined},
+ {{M,_}, _, _} = getr(restart),
+
+ %% Close an accepting watchdog immediately if there's no
+ %% restriction on the number of connections to the same peer: the
+ %% state machine never enters state REOPEN in this case. The
+ %% 'close' message (instead of stop) is so as not to bypass the
+ %% sending of messages to the service process in handle_info/2.
+
+ if T /= initial, M == accept, not R ->
+ send(self(), close),
+ S#watchdog{status = down};
+ T /= initial ->
+ set_watchdog(S#watchdog{status = down});
+ M == connect ->
+ set_watchdog(S);
+ M == accept ->
+ send(self(), close),
+ S
+ end;
%% Incoming message.
transition({recv, TPid, Name, Pkt}, #watchdog{transport = TPid} = S) ->
@@ -454,9 +476,7 @@ encode(dwr = M, Dict0, Mask) ->
hop_by_hop_id = Seq},
Pkt = #diameter_packet{header = Hdr,
msg = Msg},
- #diameter_packet{bin = Bin} = diameter_codec:encode(Dict0, Pkt),
- Bin;
-
+ diameter_codec:encode(Dict0, Pkt);
encode(dwa, Dict0, #diameter_packet{header = H, transport_data = TD}
= ReqPkt) ->
@@ -525,10 +545,14 @@ send_watchdog(#watchdog{pending = false,
dictionary = Dict0,
sequence = Mask}
= S) ->
- send(TPid, {send, encode(dwr, Dict0, Mask)}),
+ #diameter_packet{bin = Bin} = EPkt = encode(dwr, Dict0, Mask),
+ diameter_traffic:incr(send, EPkt, TPid, Dict0),
+ send(TPid, {send, Bin}),
?LOG(send, 'DWR'),
S#watchdog{pending = true}.
+%% Dont' count encode errors since we don't expect any on DWR/DWA.
+
%% recv/3
recv(Name, Pkt, S) ->
@@ -545,13 +569,29 @@ recv(Name, Pkt, S) ->
rcv('DWR', Pkt, #watchdog{transport = TPid,
dictionary = Dict0}) ->
- send(TPid, {send, encode(dwa, Dict0, Pkt)}),
+ ?LOG(recv, 'DWR'),
+ DPkt = diameter_codec:decode(Dict0, Pkt),
+ diameter_traffic:incr(recv, DPkt, TPid, Dict0),
+ diameter_traffic:incr_error(recv, DPkt, TPid, Dict0),
+ EPkt = encode(dwa, Dict0, Pkt),
+ diameter_traffic:incr(send, EPkt, TPid, Dict0),
+ diameter_traffic:incr_rc(send, EPkt, TPid, Dict0),
+
+ send(TPid, {send, EPkt}),
?LOG(send, 'DWA');
+rcv('DWA', Pkt, #watchdog{transport = TPid,
+ dictionary = Dict0}) ->
+ ?LOG(recv, 'DWA'),
+ diameter_traffic:incr(recv, Pkt, TPid, Dict0),
+ diameter_traffic:incr_rc(recv,
+ diameter_codec:decode(Dict0, Pkt),
+ TPid,
+ Dict0);
+
rcv(N, _, _)
when N == 'CER';
N == 'CEA';
- N == 'DWA';
N == 'DPR';
N == 'DPA' ->
false;
@@ -740,7 +780,7 @@ timeout(#watchdog{status = T} = S)
restart(#watchdog{transport = undefined} = S) ->
restart(getr(restart), S);
-restart(S) ->
+restart(S) -> %% reconnect has won race with timeout
S.
%% restart/2
@@ -770,9 +810,10 @@ restart({{connect, _} = T, Opts, Svc},
%% die. Note that a state machine never enters state REOPEN in this
%% case.
restart({{accept, _}, _, _}, #watchdog{restrict = {_, false}}) ->
- stop;
+ stop; %% 'DOWN' was in old code: 'close' was not sent
-%% Otherwise hang around until told to die.
+%% Otherwise hang around until told to die, either by the service or
+%% by another watchdog.
restart({{accept, _}, _, _}, S) ->
S.