[td-225] add check if cache is destoried.

src/util/src/tcache.c

@@ -190,7 +190,7 @@ SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool ext
 }
 
 void *taosCachePut(SCacheObj *pCacheObj, const void *key, size_t keyLen, const void *pData, size_t dataSize, int duration) {
-  if (pCacheObj == NULL || pCacheObj->pHashTable == NULL) {
+  if (pCacheObj == NULL || pCacheObj->pHashTable == NULL || pCacheObj->deleting == 1) {
     return NULL;
   }
 
@@ -261,7 +261,7 @@ static void incRefFn(void* ptNode) {
 }
 
 void *taosCacheAcquireByKey(SCacheObj *pCacheObj, const void *key, size_t keyLen) {
-  if (pCacheObj == NULL || taosHashGetSize(pCacheObj->pHashTable) == 0) {
+  if (pCacheObj == NULL || taosHashGetSize(pCacheObj->pHashTable) == 0 || pCacheObj->deleting == 1) {
     return NULL;
   }