From 1ca99119fdcc45da1b1363059d8c420395130175 Mon Sep 17 00:00:00 2001
From: "Matt T. Proud" <matt.proud@gmail.com>
Date: Tue, 2 Aug 2016 08:13:17 +0200
Subject: [PATCH] pkg/controller/garbagecollector: simplify mutexes.

Similar to #29598, we can rely on the zero-value construction behavior
to embed `sync.Mutex` into parent structs.
---
 pkg/controller/garbagecollector/garbagecollector.go    | 10 ++++------
 .../garbagecollector/garbagecollector_test.go          |  2 +-
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/pkg/controller/garbagecollector/garbagecollector.go b/pkg/controller/garbagecollector/garbagecollector.go
index d0576407ae..606d6308ca 100644
--- a/pkg/controller/garbagecollector/garbagecollector.go
+++ b/pkg/controller/garbagecollector/garbagecollector.go
@@ -67,7 +67,7 @@ func (s objectReference) String() string {
 type node struct {
 	identity objectReference
 	// dependents will be read by the orphan() routine, we need to protect it with a lock.
-	dependentsLock *sync.RWMutex
+	dependentsLock sync.RWMutex
 	dependents     map[*node]struct{}
 	// When processing an Update event, we need to compare the updated
 	// ownerReferences with the owners recorded in the graph.
@@ -151,8 +151,7 @@ func (p *Propagator) addDependentToOwners(n *node, owners []metatypes.OwnerRefer
 					OwnerReference: owner,
 					Namespace:      n.identity.Namespace,
 				},
-				dependentsLock: &sync.RWMutex{},
-				dependents:     make(map[*node]struct{}),
+				dependents: make(map[*node]struct{}),
 			}
 			p.uidToNode.Write(ownerNode)
 			p.gc.dirtyQueue.Add(ownerNode)
@@ -378,9 +377,8 @@ func (p *Propagator) processEvent() {
 				},
 				Namespace: accessor.GetNamespace(),
 			},
-			dependentsLock: &sync.RWMutex{},
-			dependents:     make(map[*node]struct{}),
-			owners:         accessor.GetOwnerReferences(),
+			dependents: make(map[*node]struct{}),
+			owners:     accessor.GetOwnerReferences(),
 		}
 		p.insertNode(newNode)
 		// the underlying delta_fifo may combine a creation and deletion into one event
diff --git a/pkg/controller/garbagecollector/garbagecollector_test.go b/pkg/controller/garbagecollector/garbagecollector_test.go
index 58fc5fccae..e8f9f5a701 100644
--- a/pkg/controller/garbagecollector/garbagecollector_test.go
+++ b/pkg/controller/garbagecollector/garbagecollector_test.go
@@ -301,7 +301,7 @@ func TestDependentsRace(t *testing.T) {
 	}
 
 	const updates = 100
-	owner := &node{dependentsLock: &sync.RWMutex{}, dependents: make(map[*node]struct{})}
+	owner := &node{dependents: make(map[*node]struct{})}
 	ownerUID := types.UID("owner")
 	gc.propagator.uidToNode.Write(owner)
 	go func() {