Solved 2-race-in-cache

2-race-in-cache/main.go

@@ -8,7 +8,12 @@
 
 package main
 
-import "container/list"
+import (
+	"container/list"
+	"sync"
+)
+
+var mu sync.Mutex
 
 // CacheSize determines how big the cache can grow
 const CacheSize = 100
@@ -41,12 +46,18 @@ func New(load KeyStoreCacheLoader) *KeyStoreCache {
 
 // Get gets the key from cache, loads it from the source if needed
 func (k *KeyStoreCache) Get(key string) string {
+	mu.Lock()
+	defer mu.Unlock()
+
 	if e, ok := k.cache[key]; ok {
 		k.pages.MoveToFront(e)
-		return e.Value.(page).Value
+		value := e.Value.(page).Value
+		return value
 	}
+
 	// Miss - load from database and save it in cache
 	p := page{key, k.load(key)}
+
 	// if cache is full remove the least used item
 	if len(k.cache) >= CacheSize {
 		end := k.pages.Back()
@@ -57,6 +68,7 @@ func (k *KeyStoreCache) Get(key string) string {
 	}
 	k.pages.PushFront(p)
 	k.cache[key] = k.pages.Front()
+
 	return p.Value
 }