Add diameter_dist for ready spawn_opt callbacks

That is, of functions that can be configured as spawn_opt MFAs in
transport configuration.

This commits adds the spawn_local described in the parent commit, and a
route_session that assumes that the local node initiates all sessions
with Session-Id returned by diameter:session_id/1, and handles incoming
requests on the node on which the id in question was returned,
diameter:session_id/1 using node() as optional value in the Session-Id
format.

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/diameter/src/base/diameter_traffic.erl b/lib/diameter/src/base/diameter_traffic.erl
index e9acb5c0e8..b1b797aad8 100644
--- a/lib/diameter/src/base/diameter_traffic.erl
+++ b/lib/diameter/src/base/diameter_traffic.erl
@@ -288,7 +288,9 @@ spawn_request(false, _, _, _, _, _, _) ->  %% no transport
 %% count outstanding requests. Acknowledgement is implicit if the
 %% handler process dies (in a handle_request callback for example).
 spawn_request(AppT, {M,F,A}, Ack, TPid, Pkt, Dict0, RecvData) ->
-    %% Term to pass to request/1 in an appropriate process.
+    %% Term to pass to request/1 in an appropriate process. Module
+    %% diameter_dist implements callbacks, and uses the form of the
+    %% argument tuple constructed below.
     ReqT = {Pkt, AppT, Ack, TPid, Dict0, RecvData},
     apply(M, F, [ReqT | A]);