Add events for watchdog state transitions

3 files changed, 60 insertions, 9 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index 93e2603c10..4dcbac4889 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -692,6 +692,19 @@ The packet record contains the CEA in question.</p>
 </taglist>
 </item>
 
+<tag><c>{watchdog, Ref, PeerRef, {From, To}, Config}</c></tag>
+<item>
+<code>
+Ref = transport_ref()
+PeerRef = diameter_app:peer_ref()
+From, To = initial | okay | suspect | down | reopen
+Config = {connect|listen, [transport_opt()]}
+</code>
+
+<p>
+An RFC 3539 watchdog state machine has changed state.</p>
+</item>
+
 </taglist>
 
 <p>
diff --git a/lib/diameter/src/base/diameter_service.erl b/lib/diameter/src/base/diameter_service.erl
index 3dfdcee2b2..c9c3179630 100644
--- a/lib/diameter/src/base/diameter_service.erl
+++ b/lib/diameter/src/base/diameter_service.erl
@@ -516,6 +516,14 @@ transition({reconnect, Pid}, S) ->
     reconnect(Pid, S),
     ok;
 
+%% Watchdog is sending notification of a state transition.
+transition({watchdog, Pid, {TPid, From, To}}, #state{service_name = SvcName,
+                                                     peerT = PeerT}) ->
+    #peer{ref = Ref, type = T, options = Opts}
+        = fetch(PeerT, Pid),
+    send_event(SvcName, {watchdog, Ref, TPid, {From, To}, {T, Opts}}),
+    ok;
+
 %% Monitor process has died. Just die with a reason that tells
 %% diameter_config about the happening. If a cleaner shutdown is
 %% required then someone should stop us.
diff --git a/lib/diameter/src/base/diameter_watchdog.erl b/lib/diameter/src/base/diameter_watchdog.erl
index fb22fd8275..b615bed860 100644
--- a/lib/diameter/src/base/diameter_watchdog.erl
+++ b/lib/diameter/src/base/diameter_watchdog.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2012. 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
@@ -54,7 +54,7 @@
                      %% number of DWAs received during reopen
          %% end PCB
          parent = self() :: pid(),
-         transport       :: pid(),
+         transport       :: pid() | undefined,
          tref :: reference(), %% reference for current watchdog timer
          message_data}).   %% term passed into diameter_service with message
 
@@ -64,6 +64,14 @@
 %% that a failed capabilities exchange produces the desired exit
 %% reason.
 
+-spec start(Type, {RecvData, Opts, SvcName, Svc})
+   -> pid()
+ when Type :: {connect|accept, reference()},
+      RecvData :: term(),
+      Opts :: list(),
+      SvcName :: term(),
+      Svc :: #diameter_service{}.
+
 start({_,_} = Type, T) ->
     Ref = make_ref(),
     {ok, Pid} = diameter_watchdog_sup:start_child({Ref, {Type, self(), T}}),
@@ -102,7 +110,7 @@ i({_, Pid, _} = T) ->  %% from old code
     erlang:monitor(process, Pid),
     make_state(T).
 
-make_state({T, Pid, {ConnT,
+make_state({T, Pid, {RecvData,
                      Opts,
                      SvcName,
                      #diameter_service{applications = Apps,
@@ -116,7 +124,7 @@ make_state({T, Pid, {ConnT,
               tw = proplists:get_value(watchdog_timer,
                                        Opts,
                                        ?DEFAULT_TW_INIT),
-              message_data = {ConnT, SvcName, Apps}}.
+              message_data = {RecvData, SvcName, Apps}}.
 
 %% handle_call/3
 
@@ -134,14 +142,36 @@ handle_info(T, State) ->
     case transition(T, State) of
         ok ->
             {noreply, State};
-        #watchdog{status = X} = S ->
-            ?LOGC(X =/= State#watchdog.status, transition, X),
+        #watchdog{} = S ->
+            event(State, S),
             {noreply, S};
         stop ->
             ?LOG(stop, T),
+            event(State, State#watchdog{status = down}),
             {stop, {shutdown, T}, State}
     end.
 
+event(#watchdog{status = T}, #watchdog{status = T}) ->
+    ok;
+
+event(#watchdog{transport = undefined}, #watchdog{transport = undefined}) ->
+    ok;
+
+event(#watchdog{status = From, transport = F, parent = Pid},
+      #watchdog{status = To, transport = T}) ->
+    E = {tpid(F,T), From, To},
+    notify(Pid, E),
+    ?LOG(transition, {self(), E}).
+
+tpid(_, Pid)
+  when is_pid(Pid) ->
+    Pid;
+tpid(Pid, _) ->
+    Pid.
+
+notify(Pid, E) ->
+    Pid ! {watchdog, self(), E}.
+
 %% terminate/2
 
 terminate(_, _) ->
@@ -251,8 +281,8 @@ transition({'DOWN', _, process, TPid, _},
                      status = initial}) ->
     stop;
 
-transition({'DOWN', _, process, Pid, _},
-           #watchdog{transport = Pid}
+transition({'DOWN', _, process, TPid, _},
+           #watchdog{transport = TPid}
            = S) ->
     failover(S),
     close(S),
@@ -385,7 +415,7 @@ recv(Name, Pkt, S) ->
             rcv(Name, Pkt, S),
             NS
     catch
-        throw: {?MODULE, throwaway, #watchdog{} = NS} ->
+        {?MODULE, throwaway, #watchdog{} = NS} ->
             NS
     end.