Scheduler internal NodeTree thread-safe NumNodes

pkg/scheduler/core/generic_scheduler.go

@@ -390,7 +390,7 @@ func (g *genericScheduler) findNodesThatFit(pod *v1.Pod, nodes []*v1.Node) ([]*v
 	if len(g.predicates) == 0 {
 		filtered = nodes
 	} else {
-		allNodes := int32(g.cache.NodeTree().NumNodes)
+		allNodes := int32(g.cache.NodeTree().NumNodes())
 		numNodesToFind := g.numFeasibleNodesToFind(allNodes)
 
 		// Create filtered list with enough space to avoid growing it

pkg/scheduler/internal/cache/cache_test.go

@@ -1056,7 +1056,7 @@ func TestNodeOperators(t *testing.T) {
 		if !found {
 			t.Errorf("Failed to find node %v in schedulerinternalcache.", node.Name)
 		}
-		if cache.nodeTree.NumNodes != 1 || cache.nodeTree.Next() != node.Name {
+		if cache.nodeTree.NumNodes() != 1 || cache.nodeTree.Next() != node.Name {
 			t.Errorf("cache.nodeTree is not updated correctly after adding node: %v", node.Name)
 		}
 
@@ -1099,7 +1099,7 @@ func TestNodeOperators(t *testing.T) {
 			t.Errorf("Failed to update node in schedulercache:\n got: %+v \nexpected: %+v", got, expected)
 		}
 		// Check nodeTree after update
-		if cache.nodeTree.NumNodes != 1 || cache.nodeTree.Next() != node.Name {
+		if cache.nodeTree.NumNodes() != 1 || cache.nodeTree.Next() != node.Name {
 			t.Errorf("unexpected cache.nodeTree after updating node: %v", node.Name)
 		}
 
@@ -1110,7 +1110,7 @@ func TestNodeOperators(t *testing.T) {
 		}
 		// Check nodeTree after remove. The node should be removed from the nodeTree even if there are
 		// still pods on it.
-		if cache.nodeTree.NumNodes != 0 || cache.nodeTree.Next() != "" {
+		if cache.nodeTree.NumNodes() != 0 || cache.nodeTree.Next() != "" {
 			t.Errorf("unexpected cache.nodeTree after removing node: %v", node.Name)
 		}
 	}

pkg/scheduler/internal/cache/node_tree.go

@@ -32,7 +32,7 @@ type NodeTree struct {
 	tree      map[string]*nodeArray // a map from zone (region-zone) to an array of nodes in the zone.
 	zones     []string              // a list of all the zones in the tree (keys)
 	zoneIndex int
-	NumNodes  int
+	numNodes  int
 	mu        sync.RWMutex
 }
 
@@ -91,7 +91,7 @@ func (nt *NodeTree) addNode(n *v1.Node) {
 		nt.tree[zone] = &nodeArray{nodes: []string{n.Name}, lastIndex: 0}
 	}
 	klog.V(5).Infof("Added node %v in group %v to NodeTree", n.Name, zone)
-	nt.NumNodes++
+	nt.numNodes++
 }
 
 // RemoveNode removes a node from the NodeTree.
@@ -111,7 +111,7 @@ func (nt *NodeTree) removeNode(n *v1.Node) error {
 					nt.removeZone(zone)
 				}
 				klog.V(5).Infof("Removed node %v in group %v from NodeTree", n.Name, zone)
-				nt.NumNodes--
+				nt.numNodes--
 				return nil
 			}
 		}
@@ -184,3 +184,10 @@ func (nt *NodeTree) Next() string {
 		}
 	}
 }
+
+// NumNodes returns the number of nodes.
+func (nt *NodeTree) NumNodes() int {
+	nt.mu.RLock()
+	defer nt.mu.RUnlock()
+	return nt.numNodes
+}

pkg/scheduler/internal/cache/node_tree_test.go

@@ -116,8 +116,8 @@ func verifyNodeTree(t *testing.T, nt *NodeTree, expectedTree map[string]*nodeArr
 	for _, na := range expectedTree {
 		expectedNumNodes += len(na.nodes)
 	}
-	if nt.NumNodes != expectedNumNodes {
-		t.Errorf("unexpected NodeTree.numNodes. Expected: %v, Got: %v", expectedNumNodes, nt.NumNodes)
+	if numNodes := nt.NumNodes(); numNodes != expectedNumNodes {
+		t.Errorf("unexpected NodeTree.numNodes. Expected: %v, Got: %v", expectedNumNodes, numNodes)
 	}
 	if !reflect.DeepEqual(nt.tree, expectedTree) {
 		t.Errorf("The node tree is not the same as expected. Expected: %v, Got: %v", expectedTree, nt.tree)