Merge a15ccac41e into 3fbe8634d9

credential/default_access_token.go

@@ -105,6 +105,7 @@ type StableAccessToken struct {
 	appSecret       string
 	cacheKeyPrefix  string
 	cache           cache.Cache
+	accessTokenLock *sync.Mutex
 }
 
 // NewStableAccessToken new StableAccessToken
@@ -117,6 +118,7 @@ func NewStableAccessToken(appID, appSecret, cacheKeyPrefix string, cache cache.C
 		appSecret:       appSecret,
 		cache:           cache,
 		cacheKeyPrefix:  cacheKeyPrefix,
+		accessTokenLock: new(sync.Mutex),
 	}
 }
 
@@ -130,7 +132,20 @@ func (ak *StableAccessToken) GetAccessTokenContext(ctx context.Context) (accessT
 	// 先从cache中取
 	accessTokenCacheKey := fmt.Sprintf("%s_stable_access_token_%s", ak.cacheKeyPrefix, ak.appID)
 	if val := ak.cache.Get(accessTokenCacheKey); val != nil {
-		return val.(string), nil
+		if accessToken = val.(string); accessToken != "" {
+			return
+		}
+	}
+
+	// 加上lock，是为了防止在并发获取token时，cache刚好失效，导致从微信服务器上获取到不同token
+	ak.accessTokenLock.Lock()
+	defer ak.accessTokenLock.Unlock()
+
+	// 双检，防止重复从微信服务器获取
+	if val := ak.cache.Get(accessTokenCacheKey); val != nil {
+		if accessToken = val.(string); accessToken != "" {
+			return
+		}
 	}
 
 	// cache失效，从微信服务器获取