per-client inboxes for push messages

This will avoid losing any messages received from 1 client when a push
involving another client is running.

Additionally, the handling of push initiation is improved,
it's no longer allowed to run multiples of the same type of push to
the same client.

Still stalls sometimes :(

Assistant/Types/NetMessager.hs

@@ -18,6 +18,7 @@ import Data.Text (Text)
 import qualified Data.Text as T
 import qualified Data.Set as S
 import qualified Data.Map as M
+import qualified Data.DList as D
 
 {- Messages that can be sent out of band by a network messager. -}
 data NetMessage 
@@ -117,6 +118,8 @@ mkSideMap gen = do
 getSide :: PushSide -> SideMap a -> a
 getSide side m = m side
 
+type Inboxes = TVar (M.Map ClientID (Int, D.DList NetMessage))
+
 data NetMessager = NetMessager
 	-- outgoing messages
 	{ netMessages :: TChan NetMessage
@@ -127,11 +130,11 @@ data NetMessager = NetMessager
 	-- write to this to restart the net messager
 	, netMessagerRestart :: MSampleVar ()
 	-- only one side of a push can be running at a time
-	, netMessagerPushRunning :: SideMap (TMVar (Maybe ClientID))
-	-- incoming messages related to a running push
-	, netMessagesPush :: SideMap (TChan NetMessage)
-	-- incoming push messages, deferred to be processed later
-	, netMessagesPushDeferred :: SideMap (TMVar (S.Set NetMessage))
+	-- the TMVars are empty when nothing is running
+	, netMessagerPushRunning :: SideMap (TMVar ClientID)
+	-- incoming messages containing data for a push,
+	-- on a per-client and per-side basis
+	, netMessagesInboxes :: SideMap Inboxes
 	}
 
 newNetMessager :: IO NetMessager
@@ -140,6 +143,5 @@ newNetMessager = NetMessager
 	<*> atomically (newTMVar M.empty)
 	<*> atomically (newTMVar M.empty)
 	<*> newEmptySV
-	<*> mkSideMap (newTMVar Nothing)
-	<*> mkSideMap newTChan
-	<*> mkSideMap (newTMVar S.empty)
+	<*> mkSideMap newEmptyTMVar
+	<*> mkSideMap (newTVar M.empty)