.

go/internal/xtracing/tracetest/tracetest.go

@@ -108,7 +108,7 @@ type Chan struct {
 // The goroutine which sent the message will wait for Ack before continue.
 type Msg struct {
 	Event interface {}
-	ack   chan<- bool
+	ack   chan<- bool // XXX -> chan<- error and abort tested goroutine if error?
 }
 
 
@@ -123,7 +123,7 @@ func (ch *Chan) Send(event interface{}) {
 	ch.msgq <- &Msg{event, ack}
 	ok := <-ack
 	if !ok {
-		panic(fmt.Sprintf("%s: send: deadlock", ch.name))
+		panicf("%s: send: deadlock", ch.name)
 	}
 }
 
@@ -170,7 +170,6 @@ func NewEventChecker(t testing.TB, dispatch *EventDispatcher, in *Chan) *EventCh
 // get1 gets 1 event in place and checks it has expected type
 //
 // if checks do not pass - fatal testing error is raised
-// XXX why eventp, not just event here?
 func (evc *EventChecker) xget1(eventp interface{}) *Msg {
 	evc.t.Helper()
 	var msg *Msg
@@ -179,12 +178,13 @@ func (evc *EventChecker) xget1(eventp interface{}) *Msg {
 	case msg = <-evc.in.msgq:	// unwrapped Recv
 		// ok
 
-	case <-time.After(2*time.Second):	// XXX timeout hardcoded
-		evc.deadlock(eventp)
+	case <-time.After(2*time.Second): // XXX timeout hardcoded
+		evc.deadlock(eventp)	  // XXX -> Dispatcher + allow to tune?
 	}
 
 	reventp := reflect.ValueOf(eventp)
 	if reventp.Type().Elem() != reflect.TypeOf(msg.Event) {
+		// msg.ack <- error
 		evc.t.Fatalf("%s: expect: %s:  got %#v", evc.in.name, reventp.Elem().Type(), msg.Event)
 	}
 
@@ -207,6 +207,7 @@ func (evc *EventChecker) expect1(eventExpect interface{}) *Msg {
 	revent := reventp.Elem()
 
 	if !reflect.DeepEqual(revent.Interface(), reventExpect.Interface()) {
+		// msg.ack <- error
 		evc.t.Fatalf("%s: expect: %s:\nwant: %v\nhave: %v\ndiff: %s",
 			evc.in.name,
 			reventExpect.Type(), reventExpect, revent,
@@ -242,22 +243,19 @@ func (evc *EventChecker) ExpectNoACK(expected interface{}) *Msg {
 }
 
 
-// deadlock reports diagnostic when retrieving event from .in timed out.
+// deadlock reports diagnostic when retrieving event from .in times out.
 //
-// timing out on recv means there is a deadlock either if no event was sent at
+// Timing out on recv means there is a deadlock either if no event was sent at
 // all, or some other event was sent to another channel/checker.
 //
-// report the full picture - what was expected and what was sent where.
+// Report the full picture - what was expected and what was sent where.
 func (evc *EventChecker) deadlock(eventp interface{}) {
 	evc.t.Helper()
 
-	rt := evc.dispatch.rt
-	dstv := rt.AllRoutes()
-
 	bad := fmt.Sprintf("%s: deadlock waiting for %T\n", evc.in.name, eventp)
 	type sendInfo struct{dst *Chan; event interface{}}
 	var sendv []sendInfo
-	for _, dst := range dstv {
+	for _, dst := range evc.dispatch.streams {
 		// check whether someone is sending on a dst without blocking.
 		// if yes - report to sender there is a problem - so it can cancel its task.
 		select {
@@ -295,6 +293,8 @@ func (evc *EventChecker) deadlock(eventp interface{}) {
 
 // ----------------------------------------
 
+// XXX -> Streams
+/*
 // EventRouter is the interface used for routing events to appropriate output Chan.
 //
 // It should be safe to use EventRouter from multiple goroutines simultaneously.
@@ -305,24 +305,61 @@ type EventRouter interface {
 	// AllRoutes should return all routing destinations.
 	AllRoutes() []*Chan
 }
+*/
 
+// XXX -> T
+type T = EventDispatcher
 // EventDispatcher dispatches events to appropriate Chan for checking
-// according to provided router.
+// according to provided streams.
 type EventDispatcher struct {
-	rt EventRouter
+	streams    map[/*name*/string]*Chan
+	routeEvent func(event interface{}) *Chan
 }
 
 // NewEventDispatcher creates new dispatcher and provides router to it.
-func NewEventDispatcher(router EventRouter) *EventDispatcher {
-	return &EventDispatcher{rt: router}
+func NewEventDispatcher(streams Streams) *EventDispatcher {
+	// build streams as dict and make sure all streams are named uniquely
+	streamDict := make(map[string]*Chan)
+	for _, ch := range streams.AllStreams() {
+		_, already := streamDict[ch.name]
+		if already {
+			panicf("duplicate stream name %q", ch.name)
+		}
+		streamDict[ch.name] = ch
+	}
+	return &EventDispatcher{
+		streams:    streamDict,
+		routeEvent: streams.RouteEvent,
+	}
 }
 
+// XXX -> tracetest.T ?
 // Dispatch dispatches event to appropriate output channel.
 //
 // It is safe to use Dispatch from multiple goroutines simultaneously.
 func (d *EventDispatcher) Dispatch(event interface{}) {
-	outch := d.rt.Route(event)
-	// XXX if nil?
+	ch := d.routeEvent(event)
+
+	// assert that ch is within AllStreams() return.
+	if ch == nil {
+		panicf("Event %#v routed to nil", event)
+	}
+/* XXX deactivated for now because neo.tNewCluster creates NewEventDispatcher with initially empty router
+	ch_, ok := d.streams[ch.name]
+	if !ok {
+		all := []string{}
+		for name := range d.streams {
+			all = append(all, name)
+		}
+		sort.Slice(all, func(i, j int) bool {
+			return strings.Compare(all[i], all[j]) < 0
+		})
+		panicf("Event %#v routed to stream %q that is outside of AllStreams %q", event, ch.name, all)
+	}
+	if ch != ch_ {
+		panicf("Event %#v routed to stream %q, but channel is different from what AllSteams[%q] originally reported", event, ch.name, ch.name)
+	}
+*/
 
 	// TODO it is possible to emperically detect here if a test incorrectly
 	// decomposed its system into serial streams: consider unrelated to each
@@ -356,5 +393,45 @@ func (d *EventDispatcher) Dispatch(event interface{}) {
 	//
 	// XXX -> if deadlock detection is done on receiver side (so in
 	// EventChecker) -> we don't need EventDispatcher at all?
-	outch.Send(event)
+	ch.Send(event)
+}
+
+
+// Streams represents decomposition for events in a system into serial streams.
+type Streams interface {
+	// AllStreams should return all streams of the system.
+	// Streams must have unique names.
+	AllStreams() []*Chan
+
+	// RouteEvent should return particular stream into which event should be routed.
+	// Returned stream must be one of reported by AllStreams.
+	RouteEvent(event interface{}) *Chan
+}
+
+
+// TODO func Verify(system)
+// system() ->:
+// (Streams)
+// - []Chan			where events will be emitted
+// - Route(event) -> Chan	which event goes to which event stream (= channel)
+//
+// - main			func to run the system
+// - testf			(serial) func to verify events that comes from channels
+
+// Verify verifies a system.
+// XXX
+func Verify(system func() (
+	Streams,
+	/*main*/  func(),
+	/*testf*/ func(t *T),
+)) {
+	// XXX
+}
+
+
+
+// ---- misc ----
+
+func panicf(format string, argv ...interface{}) {
+	panic(fmt.Sprintf(format, argv...))
 }

go/neo/t_cluster_test.go

@@ -52,7 +52,14 @@ type tCluster struct {
 
 	tabMu     sync.Mutex
 	nodeTab	  map[string/*node*/]*tNode
-	checkTab  map[string/*node*/]*tracetest.EventChecker
+	// checkTab keeps event checkers for the following event streams:
+	//   1) events specific to a node, and
+	//   2) events specific to exchange in between node1-node2 for
+	//      communications that originate at node1.
+	//
+	// NOTE that node1-node2 and node2-node1 are different and come with
+	// separate event checkers.
+	checkTab  map[string/*node, or node1->node2*/]*tracetest.EventChecker
 }
 
 // tNode represents information about a test node ... XXX
@@ -124,7 +131,7 @@ func (t *tCluster) Checker(name string) *tracetest.EventChecker {
 
 	c, ok := t.checkTab[name]
 	if !ok {
-		panic(fmt.Sprintf("test cluster: no %q checker", name))
+		panic(fmt.Sprintf("test cluster: no checker for %q", name))
 	}
 
 	return c
@@ -177,7 +184,7 @@ func (t *tCluster) registerNewNode(name string) *tNode {
 // The master will be accepting incoming connections at node:1.
 // The node must be not yet existing and will be dedicated to the created master fully.	XXX
 //
-// XXX error of creating py process?
+// XXX error of creating py process? -> t.Fatal
 func (t *tCluster) NewMaster(name string) ITestMaster {
 	node := t.registerNewNode(name)
 	m := tNewMaster(t.name, ":1", node.net)

go/neo/t_events_test.go

@@ -67,7 +67,7 @@ type eventNeoSend struct {
 // event: cluster state changed
 type eventClusterState struct {
 	//Ptr   *neo.ClusterState // pointer to variable which holds the state
-	Where string
+	Where string              // XXX document what Where means - (host name of a node ?)
 	State proto.ClusterState
 }
 
@@ -157,6 +157,7 @@ func δnode(where string, laddr string, typ proto.NodeType, num int32, state pro
 type EventRouter struct {
 	mu sync.Mutex
 
+	// XXX all unbranched events go to here?
 	defaultq *tracetest.Chan
 
 	// events specific to particular node - e.g. node starts listening,
@@ -181,6 +182,16 @@ type EventRouter struct {
 	connected map[string /*addr-addr*/]bool
 }
 
+// linkDst represents destination for events on a network link.
+//
+// Events go to either a or b depending on which side initiated particular
+// connection on top of the link.
+type linkDst struct {
+	a *tracetest.Chan // net cause was on dialer
+	b *tracetest.Chan // net cause was on listener
+}
+
+
 func NewEventRouter() *EventRouter {
 	return &EventRouter{
 		defaultq:	tracetest.NewChan("default"),
@@ -191,7 +202,7 @@ func NewEventRouter() *EventRouter {
 	}
 }
 
-func (r *EventRouter) AllRoutes() []*tracetest.Chan {
+func (r *EventRouter) AllStreams() []*tracetest.Chan {
 	rtset := map[*tracetest.Chan]int{}
 	rtset[r.defaultq] = 1
 	for _, dst := range r.byNode {
@@ -234,7 +245,7 @@ func host(addr string) string {
 }
 
 // Route routes events according to rules specified via Branch*().
-func (r *EventRouter) Route(event interface{}) (dst *tracetest.Chan) {
+func (r *EventRouter) RouteEvent(event interface{}) (dst *tracetest.Chan) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
@@ -376,13 +387,3 @@ func (r *EventRouter) BranchLink(link string, dsta, dstb *tracetest.Chan) {
 
 	r.byLink[link] = &linkDst{dsta, dstb}
 }
-
-// linkDst represents destination for events on a network link.
-//
-// Events go to either a or b depending on which side initiated particular
-// connection on top of the link.
-type linkDst struct {
-	a *tracetest.Chan // net cause was on dialer
-	b *tracetest.Chan // net cause was on listener
-}
-