Added Trace to signal so that nodes can discard based on direction

event.go

@@ -12,12 +12,12 @@ import (
 // Update the events listeners, and notify the parent to do the same
 func (event * BaseEvent) update(signal GraphSignal) {
   event.signal <- signal
-
+  new_signal := signal.Trace(event.ID())
   if event.parent != nil && signal.Type() != "abort"{
-    SendUpdate(event.parent, signal)
+    SendUpdate(event.parent, new_signal)
   } else if signal.Type() == "abort" {
     for _, child := range(event.Children()) {
-      SendUpdate(child, signal)
+      SendUpdate(child, new_signal)
     }
   }
 }

graph.go

@@ -18,6 +18,8 @@ type GraphSignal interface {
   Type() string
   Description() string
   Time() time.Time
+  Last() string
+  Trace(id string) GraphSignal
 }
 
 type BaseSignal struct {
@@ -25,6 +27,7 @@ type BaseSignal struct {
   signal_type string
   description string
   time time.Time
+  last_id string
 }
 
 func (signal BaseSignal) Time() time.Time {
@@ -43,6 +46,16 @@ func (signal BaseSignal) Description() string {
   return signal.description
 }
 
+func (signal BaseSignal) Trace(id string) GraphSignal {
+  new_signal := signal
+  new_signal.last_id = id
+  return new_signal
+}
+
+func (signal BaseSignal) Last() string {
+  return signal.last_id
+}
+
 func NewSignal(source GraphNode, signal_type string) (BaseSignal) {
   signal := BaseSignal{
     source: source,

resource.go

@@ -9,19 +9,21 @@ import (
 // Resources propagate update up to multiple parents, and not downwards
 // (subscriber to team won't get update to alliance, but subscriber to alliance will get update to team)
 func (resource * BaseResource) update(signal GraphSignal) {
+  new_signal := signal.Trace(resource.ID())
   if signal.Type() == "lock_changed" {
     for _, child := range resource.Children() {
-      SendUpdate(child, signal)
+      SendUpdate(child, new_signal)
     }
   } else {
     for _, parent := range resource.Parents() {
-      SendUpdate(parent, signal)
+      SendUpdate(parent, new_signal)
     }
     if resource.lock_holder != nil {
-      SendUpdate(resource.lock_holder, signal)
+      if resource.lock_holder.ID() != signal.Last() {
+        SendUpdate(resource.lock_holder, new_signal)
+      }
     }
   }
-
 }
 
 // Resource is the interface that DAG nodes are made from

vex.go

@@ -64,13 +64,6 @@ func NewAlliance(team0 * Team, team1 * Team) * Alliance {
   return resource
 }
 
-type Match struct {
-  BaseEvent
-  state string
-  control string
-  control_start time.Time
-}
-
 type Arena struct {
   BaseResource
   connected bool
@@ -96,8 +89,9 @@ func (arena * Arena) lock(event Event) error {
 
 func (arena * Arena) update(signal GraphSignal) {
   log.Printf("ARENA_UPDATE: %s", arena.Name())
-  arena.BaseResource.update(signal)
   arena.signal <- signal
+  new_signal := signal.Trace(arena.ID())
+  arena.BaseResource.update(new_signal)
 }
 
 func (arena * Arena) Connect(abort chan error) bool {
@@ -147,6 +141,22 @@ const start_slack = 3000 * time.Millisecond
 const TEMP_AUTON_TIME = time.Second * 3
 const TEMP_DRIVE_TIME = time.Second * 5
 
+type Match struct {
+  BaseEvent
+  arena * Arena
+  state string
+  control string
+  control_start time.Time
+}
+
+func (match * Match) update(signal GraphSignal) {
+  new_signal := signal.Trace(match.ID())
+  match.BaseEvent.update(new_signal)
+  if match.arena.ID() != signal.Last() {
+    SendUpdate(match.arena, new_signal)
+  }
+}
+
 func NewMatch(alliance0 * Alliance, alliance1 * Alliance, arena * Arena) * Match {
   name := fmt.Sprintf("Match: %s vs. %s on %s", alliance0.Name(), alliance1.Name(), arena.Name())
   description := "A vex match"
@@ -156,6 +166,7 @@ func NewMatch(alliance0 * Alliance, alliance1 * Alliance, arena * Arena) * Match
     state: "init",
     control: "init",
     control_start: time.UnixMilli(0),
+    arena: arena,
   }
 
   match.actions["start"] = func() (string, error) {

vex_test.go

@@ -131,9 +131,9 @@ func TestNewMatch(t *testing.T) {
   alliance_2 := NewAlliance(team_3, team_4)
 
   arena := NewVirtualArena(arena_name)
+  arena_c := arena.UpdateChannel()
 
   match := NewMatch(alliance_1, alliance_2, arena)
-  match_c := match.UpdateChannel()
   root_event := NewEventQueue("root_event", "", []Resource{})
   r := root_event.DoneResource()
 
@@ -148,34 +148,34 @@ func TestNewMatch(t *testing.T) {
     }
   }()
 
-  go func(match_c chan GraphSignal) {
-    (*graph_tester)(t).WaitForValue(match_c, "event_start", 1*time.Second, "no event_start")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after starting")
+  go func(arena_c chan GraphSignal) {
+    (*graph_tester)(t).WaitForValue(arena_c, "event_start", 1*time.Second, "no event_start")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after starting")
     SendUpdate(arena, NewSignal(nil, "queue_autonomous"))
-    (*graph_tester)(t).WaitForValue(match_c, "autonomous_queued", 1*time.Second, "no autonomous_queued")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after queueing autonomous")
+    (*graph_tester)(t).WaitForValue(arena_c, "autonomous_queued", 1*time.Second, "no autonomous_queued")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after queueing autonomous")
     auton_signal := NewSignal(nil, "start_autonomous")
     auton_signal.time = time.Now()
     SendUpdate(arena, auton_signal)
-    (*graph_tester)(t).WaitForValue(match_c, "autonomous_running", 1*time.Second, "no autonomous_running")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after starting autonomous")
+    (*graph_tester)(t).WaitForValue(arena_c, "autonomous_running", 1*time.Second, "no autonomous_running")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after starting autonomous")
     time.Sleep(TEMP_AUTON_TIME)
     time.Sleep(time.Millisecond * 100)
-    (*graph_tester)(t).WaitForValue(match_c, "autonomous_done", 6*time.Second, "no autonomous_done")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after ending autonomous")
+    (*graph_tester)(t).WaitForValue(arena_c, "autonomous_done", 6*time.Second, "no autonomous_done")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after ending autonomous")
     SendUpdate(arena, NewSignal(nil, "queue_driver"))
-    (*graph_tester)(t).WaitForValue(match_c, "driver_queued", 1*time.Second, "no driver_queued")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after queueing driver")
+    (*graph_tester)(t).WaitForValue(arena_c, "driver_queued", 1*time.Second, "no driver_queued")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after queueing driver")
     driver_signal := NewSignal(nil, "start_driver")
     driver_signal.time = time.Now()
     SendUpdate(arena, driver_signal)
-    (*graph_tester)(t).WaitForValue(match_c, "driver_running", 1*time.Second, "no driver_running")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after starting driver")
+    (*graph_tester)(t).WaitForValue(arena_c, "driver_running", 1*time.Second, "no driver_running")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after starting driver")
     time.Sleep(TEMP_DRIVE_TIME)
     time.Sleep(time.Millisecond * 100)
-    (*graph_tester)(t).WaitForValue(match_c, "driver_done", 1*time.Second, "no driver_done")
-    (*graph_tester)(t).CheckForNone(match_c, "update to match after game done 3")
-  }(match_c)
+    (*graph_tester)(t).WaitForValue(arena_c, "driver_done", 1*time.Second, "no driver_done")
+    (*graph_tester)(t).CheckForNone(arena_c, "update to match after game done 3")
+  }(arena_c)
 
   err := event_manager.Run()
   if err != nil {