Make sure to unpause all elements when resuming

The indegree code added a regression because elements with an indegree
would not be unpaused! This is now corrected. Time to add more tests :)

exec.go

@@ -104,6 +104,7 @@ func (obj *ExecType) Watch() {
 	defer obj.SetWatching(false)
 
 	var send = false // send event?
+	var exit = false
 	bufioch, errch := make(chan string), make(chan error)
 	//vertex := obj.GetVertex()         // stored with SetVertex
 
@@ -171,10 +172,9 @@ func (obj *ExecType) Watch() {
 
 		case event := <-obj.events:
 			obj.SetConvergedState(typeConvergedNil)
-			if ok := obj.ReadEvent(&event); !ok {
+			if exit, send = obj.ReadEvent(&event); exit {
 				return // exit
 			}
-			send = true
 
 		case _ = <-TimeAfterOrBlock(obj.ctimeout):
 			obj.SetConvergedState(typeConvergedTimeout)

file.go

@@ -120,6 +120,7 @@ func (obj *FileType) Watch() {
 	var current string               // current "watcher" location
 	var delta_depth int              // depth delta between watcher and event
 	var send = false                 // send event?
+	var exit = false
 	var dirty = false
 
 	for {
@@ -234,10 +235,9 @@ func (obj *FileType) Watch() {
 
 		case event := <-obj.events:
 			obj.SetConvergedState(typeConvergedNil)
-			if ok := obj.ReadEvent(&event); !ok {
+			if exit, send = obj.ReadEvent(&event); exit {
 				return // exit
 			}
-			send = true
 			//dirty = false // these events don't invalidate state
 
 		case _ = <-TimeAfterOrBlock(obj.ctimeout):

main.go

@@ -158,7 +158,7 @@ func run(c *cli.Context) {
 			// loops, we'll cause G.Pause(...) before we
 			// even got going, thus causing nil pointer errors
 			log.Printf("State: %v -> %v", G.SetState(graphStarting), G.GetState())
-			G.Start(&wg) // sync
+			G.Start(&wg, first) // sync
 			log.Printf("State: %v -> %v", G.SetState(graphStarted), G.GetState())
 			first = false
 		}

pgraph.go

@@ -543,8 +543,9 @@ func HeisenbergCount(ch chan *Vertex) int {
 }
 
 // main kick to start the graph
-func (g *Graph) Start(wg *sync.WaitGroup) { // start or continue
+func (g *Graph) Start(wg *sync.WaitGroup, first bool) { // start or continue
 	t, _ := g.TopologicalSort()
+	// TODO: only calculate indegree if `first` is true to save resources
 	indegree := g.InDegree() // compute all of the indegree's
 	for _, v := range Reverse(t) {
 
@@ -568,7 +569,10 @@ func (g *Graph) Start(wg *sync.WaitGroup) { // start or continue
 		// failures, such as any poke limiting code in Poke() or
 		// BackPoke(). You might want to disable this selective start
 		// when experimenting with and testing those elements.
-		if indegree[v] == 0 {
+		// if we are unpausing (since it's not the first run of this
+		// function) we need to poke to *unpause* every graph vertex,
+		// and not just selectively the subset with no indegree.
+		if (!first) || indegree[v] == 0 {
 			// ensure state is started before continuing on to next vertex
 			for !v.Type.SendEvent(eventStart, true, false) {
 				if DEBUG {

service.go

@@ -82,6 +82,7 @@ func (obj *ServiceType) Watch() {
 
 	var service = fmt.Sprintf("%v.service", obj.Name) // systemd name
 	var send = false                                  // send event?
+	var exit = false
 	var dirty = false
 	var invalid = false              // does the service exist or not?
 	var previous bool                // previous invalid value
@@ -132,13 +133,13 @@ func (obj *ServiceType) Watch() {
 
 			case event := <-obj.events:
 				obj.SetConvergedState(typeConvergedNil)
-				if ok := obj.ReadEvent(&event); !ok {
+				if exit, send = obj.ReadEvent(&event); exit {
 					return // exit
 				}
 				if event.GetActivity() {
 					dirty = true
 				}
-				send = true
+
 			case _ = <-TimeAfterOrBlock(obj.ctimeout):
 				obj.SetConvergedState(typeConvergedTimeout)
 				obj.converged <- true
@@ -181,13 +182,12 @@ func (obj *ServiceType) Watch() {
 
 			case event := <-obj.events:
 				obj.SetConvergedState(typeConvergedNil)
-				if ok := obj.ReadEvent(&event); !ok {
+				if exit, send = obj.ReadEvent(&event); exit {
 					return // exit
 				}
 				if event.GetActivity() {
 					dirty = true
 				}
-				send = true
 			}
 		}
 

types.go

@@ -255,22 +255,22 @@ func (obj *BaseType) SendEvent(event eventName, sync bool, activity bool) bool {
 	}
 }
 
-// process events when a select gets one
-// this handles the pause code too!
-func (obj *BaseType) ReadEvent(event *Event) bool {
+// process events when a select gets one, this handles the pause code too!
+// the return values specify if we should exit and poke respectively
+func (obj *BaseType) ReadEvent(event *Event) (exit, poke bool) {
 	event.ACK()
 	switch event.Name {
 	case eventStart:
-		return true
+		return false, true
 
 	case eventPoke:
-		return true
+		return false, true
 
 	case eventBackPoke:
-		return true
+		return false, true // forward poking in response to a back poke!
 
 	case eventExit:
-		return false
+		return true, false
 
 	case eventPause:
 		// wait for next event to continue
@@ -278,18 +278,19 @@ func (obj *BaseType) ReadEvent(event *Event) bool {
 		case e := <-obj.events:
 			e.ACK()
 			if e.Name == eventExit {
-				return false
+				return true, false
 			} else if e.Name == eventStart { // eventContinue
-				return true
+				return false, false // don't poke on unpause!
 			} else {
-				log.Fatal("Unknown event: ", e)
+				// if we get a poke event here, it's a bug!
+				log.Fatalf("%v[%v]: Unknown event: %v, while paused!", obj.GetType(), obj.GetName(), e)
 			}
 		}
 
 	default:
 		log.Fatal("Unknown event: ", event)
 	}
-	return false // required to keep the stupid go compiler happy
+	return true, false // required to keep the stupid go compiler happy
 }
 
 // useful for using as: return CleanState() in the StateOK functions when there
@@ -355,16 +356,16 @@ func (obj *NoopType) Watch() {
 
 	//vertex := obj.vertex // stored with SetVertex
 	var send = false // send event?
+	var exit = false
 	for {
 		obj.SetState(typeWatching) // reset
 		select {
 		case event := <-obj.events:
 			obj.SetConvergedState(typeConvergedNil)
-			if ok := obj.ReadEvent(&event); !ok {
+			// we avoid sending events on unpause
+			if exit, send = obj.ReadEvent(&event); exit {
 				return // exit
 			}
-			// XXX: should we avoid sending events on UNPAUSE ?
-			send = true
 
 		case _ = <-TimeAfterOrBlock(obj.ctimeout):
 			obj.SetConvergedState(typeConvergedTimeout)