resources: Fix poke/refresh race

Clearly the use of errgroup is flawed.
1) You can't pass in variables, so this is likely to race.
2) You can't get a set of errors, so this is a bad API.

For the second problem, it would be much more sane to return a multierr
or a list of errors. If there's no fix for the first, I think it should
be removed from the lib.

pgraph/actions.go

@@ -29,7 +29,6 @@ import (
 	"github.com/purpleidea/mgmt/resources"
 
 	errwrap "github.com/pkg/errors"
-	"golang.org/x/sync/errgroup"
 )
 
 // GetTimestamp returns the timestamp of a vertex
@@ -65,7 +64,7 @@ func (g *Graph) OKTimestamp(v *Vertex) bool {
 // Poke notifies nodes after me in the dependency graph that they need refreshing...
 // NOTE: this assumes that this can never fail or need to be rescheduled
 func (g *Graph) Poke(v *Vertex, activity bool) error {
-	var eg errgroup.Group
+	var wg sync.WaitGroup
 	// these are all the vertices pointing AWAY FROM v, eg: v -> ???
 	for _, n := range g.OutgoingGraphVertices(v) {
 		// XXX: if we're in state event and haven't been cancelled by
@@ -75,17 +74,17 @@ func (g *Graph) Poke(v *Vertex, activity bool) error {
 			if global.DEBUG {
 				log.Printf("%s[%s]: Poke: %s[%s]", v.Kind(), v.GetName(), n.Kind(), n.GetName())
 			}
-			//wg.Add(1)
-			eg.Go(func() error {
-				//defer wg.Done()
-				edge := g.Adjacency[v][n] // lookup
+			wg.Add(1)
+			go func(nn *Vertex) error {
+				defer wg.Done()
+				edge := g.Adjacency[v][nn] // lookup
 				notify := edge.Notify && edge.Refresh()
 
 				// FIXME: is it okay that this is sync?
-				n.SendEvent(event.EventPoke, true, notify)
+				nn.SendEvent(event.EventPoke, true, notify)
 				// TODO: check return value?
 				return nil // never error for now...
-			})
+			}(n)
 
 		} else {
 			if global.DEBUG {
@@ -93,7 +92,8 @@ func (g *Graph) Poke(v *Vertex, activity bool) error {
 			}
 		}
 	}
-	return eg.Wait() // wait for all the pokes to complete
+	wg.Wait() // wait for all the pokes to complete
+	return nil
 }
 
 // BackPoke pokes the pre-requisites that are stale and need to run before I can run.
@@ -219,7 +219,10 @@ func (g *Graph) Process(v *Vertex) error {
 		// if CheckApply ran without noop and without error, state should be good
 		if !noop && err == nil { // aka !noop || checkOK
 			obj.StateOK(true) // reset
+			if refresh {
 				g.SetUpstreamRefresh(v, false) // refresh happened, clear the request
+				obj.SetRefresh(false)
+			}
 		}
 
 		if !checkOK { // if state *was* not ok, we had to have apply'ed

resources/sendrecv.go

@@ -65,7 +65,7 @@ func (obj *BaseRes) ReadEvent(ev *event.Event) (exit, send bool) {
 		poke = true        // poke!
 		// XXX: this should be elsewhere in case Watch isn't used (eg: Polling instead...)
 		// XXX: unless this is used in our "fallback" polling implementation???
-		obj.SetRefresh(true)
+		//obj.SetRefresh(true) // TODO: is this redundant?
 	}
 
 	switch ev.Name {