Hide EquivalenceCache mutex from users.

Since the equiv. cache lock no longer needs to be held across multiple
method calls, move the locking inside and don't expose it to users.

pkg/scheduler/core/equivalence_cache.go

@@ -38,7 +38,7 @@ const maxCacheEntries = 100
 // 1. a map of AlgorithmCache with node name as key
 // 2. function to get equivalence pod
 type EquivalenceCache struct {
-	sync.RWMutex
+	mu             sync.Mutex
 	algorithmCache map[string]AlgorithmCache
 }
 
@@ -84,9 +84,9 @@ func (ec *EquivalenceCache) RunPredicate(
 	equivClassInfo *equivalenceClassInfo,
 	cache schedulercache.Cache,
 ) (bool, []algorithm.PredicateFailureReason, error) {
-	ec.Lock()
-	defer ec.Unlock()
-	fit, reasons, invalid := ec.lookupResult(pod.GetName(), nodeInfo.Node().GetName(), predicateKey, equivClassInfo.hash, false)
+	ec.mu.Lock()
+	defer ec.mu.Unlock()
+	fit, reasons, invalid := ec.lookupResult(pod.GetName(), nodeInfo.Node().GetName(), predicateKey, equivClassInfo.hash)
 	if !invalid {
 		return fit, reasons, nil
 	}
@@ -96,7 +96,7 @@ func (ec *EquivalenceCache) RunPredicate(
 	}
 	// Skip update if NodeInfo is stale.
 	if cache != nil && cache.IsUpToDate(nodeInfo) {
-		ec.updateResult(pod.GetName(), nodeInfo.Node().GetName(), predicateKey, fit, reasons, equivClassInfo.hash, false)
+		ec.updateResult(pod.GetName(), nodeInfo.Node().GetName(), predicateKey, fit, reasons, equivClassInfo.hash)
 	}
 	return fit, reasons, nil
 }
@@ -107,12 +107,7 @@ func (ec *EquivalenceCache) updateResult(
 	fit bool,
 	reasons []algorithm.PredicateFailureReason,
 	equivalenceHash uint64,
-	needLock bool,
 ) {
-	if needLock {
-		ec.Lock()
-		defer ec.Unlock()
-	}
 	if _, exist := ec.algorithmCache[nodeName]; !exist {
 		ec.algorithmCache[nodeName] = newAlgorithmCache()
 	}
@@ -140,12 +135,8 @@ func (ec *EquivalenceCache) updateResult(
 // 3. if cache item is not found
 func (ec *EquivalenceCache) lookupResult(
 	podName, nodeName, predicateKey string,
-	equivalenceHash uint64, needLock bool,
+	equivalenceHash uint64,
 ) (bool, []algorithm.PredicateFailureReason, bool) {
-	if needLock {
-		ec.RLock()
-		defer ec.RUnlock()
-	}
 	glog.V(5).Infof("Begin to calculate predicate: %v for pod: %s on node: %s based on equivalence cache",
 		predicateKey, podName, nodeName)
 	if algorithmCache, exist := ec.algorithmCache[nodeName]; exist {
@@ -170,8 +161,8 @@ func (ec *EquivalenceCache) InvalidateCachedPredicateItem(nodeName string, predi
 	if len(predicateKeys) == 0 {
 		return
 	}
-	ec.Lock()
-	defer ec.Unlock()
+	ec.mu.Lock()
+	defer ec.mu.Unlock()
 	if algorithmCache, exist := ec.algorithmCache[nodeName]; exist {
 		for predicateKey := range predicateKeys {
 			algorithmCache.predicatesCache.Remove(predicateKey)
@@ -185,8 +176,8 @@ func (ec *EquivalenceCache) InvalidateCachedPredicateItemOfAllNodes(predicateKey
 	if len(predicateKeys) == 0 {
 		return
 	}
-	ec.Lock()
-	defer ec.Unlock()
+	ec.mu.Lock()
+	defer ec.mu.Unlock()
 	// algorithmCache uses nodeName as key, so we just iterate it and invalid given predicates
 	for _, algorithmCache := range ec.algorithmCache {
 		for predicateKey := range predicateKeys {
@@ -199,8 +190,8 @@ func (ec *EquivalenceCache) InvalidateCachedPredicateItemOfAllNodes(predicateKey
 
 // InvalidateAllCachedPredicateItemOfNode marks all cached items on given node as invalid
 func (ec *EquivalenceCache) InvalidateAllCachedPredicateItemOfNode(nodeName string) {
-	ec.Lock()
-	defer ec.Unlock()
+	ec.mu.Lock()
+	defer ec.mu.Unlock()
 	delete(ec.algorithmCache, nodeName)
 	glog.V(5).Infof("Done invalidating all cached predicates on node: %s", nodeName)
 }

pkg/scheduler/core/equivalence_cache_test.go

@@ -253,7 +253,9 @@ func TestRunPredicate(t *testing.T) {
 			ecache := NewEquivalenceCache()
 			equivClass := ecache.getEquivalenceClassInfo(pod)
 			if test.expectCacheHit {
+				ecache.mu.Lock()
 				ecache.updateResult(pod.Name, node.Node().Name, "testPredicate", test.expectFit, test.expectedReasons, equivClass.hash)
+				ecache.mu.Unlock()
 			}
 
 			fit, reasons, err := ecache.RunPredicate(test.pred.predicate, "testPredicate", pod, meta, node, equivClass, test.cache)
@@ -287,7 +289,9 @@ func TestRunPredicate(t *testing.T) {
 			if !test.expectCacheHit && test.pred.callCount == 0 {
 				t.Errorf("Predicate should be called")
 			}
+			ecache.mu.Lock()
 			_, _, invalid := ecache.lookupResult(pod.Name, node.Node().Name, "testPredicate", equivClass.hash)
+			ecache.mu.Unlock()
 			if invalid && test.expectCacheWrite {
 				t.Errorf("Cache write should happen")
 			}
@@ -350,6 +354,7 @@ func TestUpdateResult(t *testing.T) {
 					test.equivalenceHash: predicateItem,
 				})
 		}
+		ecache.mu.Lock()
 		ecache.updateResult(
 			test.pod,
 			test.nodeName,
@@ -357,8 +362,8 @@ func TestUpdateResult(t *testing.T) {
 			test.fit,
 			test.reasons,
 			test.equivalenceHash,
-			true,
 		)
+		ecache.mu.Unlock()
 
 		value, ok := ecache.algorithmCache[test.nodeName].predicatesCache.Get(test.predicateKey)
 		if !ok {
@@ -460,6 +465,7 @@ func TestLookupResult(t *testing.T) {
 	for _, test := range tests {
 		ecache := NewEquivalenceCache()
 		// set cached item to equivalence cache
+		ecache.mu.Lock()
 		ecache.updateResult(
 			test.podName,
 			test.nodeName,
@@ -467,8 +473,8 @@ func TestLookupResult(t *testing.T) {
 			test.cachedItem.fit,
 			test.cachedItem.reasons,
 			test.equivalenceHashForUpdatePredicate,
-			true,
 		)
+		ecache.mu.Unlock()
 		// if we want to do invalid, invalid the cached item
 		if test.expectedInvalidPredicateKey {
 			predicateKeys := sets.NewString()
@@ -476,12 +482,13 @@ func TestLookupResult(t *testing.T) {
 			ecache.InvalidateCachedPredicateItem(test.nodeName, predicateKeys)
 		}
 		// calculate predicate with equivalence cache
+		ecache.mu.Lock()
 		fit, reasons, invalid := ecache.lookupResult(test.podName,
 			test.nodeName,
 			test.predicateKey,
 			test.equivalenceHashForCalPredicate,
-			true,
 		)
+		ecache.mu.Unlock()
 		// returned invalid should match expectedInvalidPredicateKey or expectedInvalidEquivalenceHash
 		if test.equivalenceHashForUpdatePredicate != test.equivalenceHashForCalPredicate {
 			if invalid != test.expectedInvalidEquivalenceHash {
@@ -668,6 +675,7 @@ func TestInvalidateCachedPredicateItemOfAllNodes(t *testing.T) {
 
 	for _, test := range tests {
 		// set cached item to equivalence cache
+		ecache.mu.Lock()
 		ecache.updateResult(
 			test.podName,
 			test.nodeName,
@@ -675,8 +683,8 @@ func TestInvalidateCachedPredicateItemOfAllNodes(t *testing.T) {
 			test.cachedItem.fit,
 			test.cachedItem.reasons,
 			test.equivalenceHashForUpdatePredicate,
-			true,
 		)
+		ecache.mu.Unlock()
 	}
 
 	// invalidate cached predicate for all nodes
@@ -735,6 +743,7 @@ func TestInvalidateAllCachedPredicateItemOfNode(t *testing.T) {
 
 	for _, test := range tests {
 		// set cached item to equivalence cache
+		ecache.mu.Lock()
 		ecache.updateResult(
 			test.podName,
 			test.nodeName,
@@ -742,8 +751,8 @@ func TestInvalidateAllCachedPredicateItemOfNode(t *testing.T) {
 			test.cachedItem.fit,
 			test.cachedItem.reasons,
 			test.equivalenceHashForUpdatePredicate,
-			true,
 		)
+		ecache.mu.Unlock()
 	}
 
 	for _, test := range tests {