tcache cleanup [1/n]

Fix a memory leak in strdup in error path.

* testing
taosdemo
Spent 97.5608 seconds to insert rows: 100000000, affected rows: 100000000 with 8 thread(s) into test.meters. 1025002.08 records/second

insert delay, avg:      77.49ms, max:     344.74ms, min:      27.19ms

src/util/src/tcache.c

@@ -85,7 +85,7 @@ static void doInitRefreshThread(void) {
   pthread_attr_destroy(&thattr);
 }
 
-pthread_t doRegisterCacheObj(SCacheObj* pCacheObj) {
+static pthread_t doRegisterCacheObj(SCacheObj* pCacheObj) {
   pthread_once(&cacheThreadInit, doInitRefreshThread);
 
   pthread_mutex_lock(&guard);
@@ -184,7 +184,7 @@ static FORCE_INLINE void doDestroyTrashcanElem(SCacheObj* pCacheObj, STrashElem
 }
 
 SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool extendLifespan, __cache_free_fn_t fn, const char* cacheName) {
-  const int32_t SLEEP_DURATION = 500; //500 ms
+  const int32_t SLEEP_DURATION_IN_MS = 500;
 
   if (refreshTimeInSeconds <= 0) {
     return NULL;
@@ -197,21 +197,29 @@ SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool ext
   }
 
   pCacheObj->pHashTable = taosHashInit(4096, taosGetDefaultHashFunction(keyType), false, HASH_ENTRY_LOCK);
-  pCacheObj->name = strdup(cacheName);
   if (pCacheObj->pHashTable == NULL) {
     free(pCacheObj);
     uError("failed to allocate memory, reason:%s", strerror(errno));
     return NULL;
   }
 
+  pCacheObj->name = strdup(cacheName);
+  if (pCacheObj->name == NULL) {
+    taosHashCleanup(pCacheObj->pHashTable);
+    free(pCacheObj);
+    uError("failed to allocate memory, reason:%s", strerror(errno));
+    return NULL;
+  }
+
   // set free cache node callback function
   pCacheObj->freeFp      = fn;
   pCacheObj->refreshTime = refreshTimeInSeconds * 1000;
-  pCacheObj->checkTick   = pCacheObj->refreshTime / SLEEP_DURATION;
+  pCacheObj->checkTick   = pCacheObj->refreshTime / SLEEP_DURATION_IN_MS;
   pCacheObj->extendLifespan = extendLifespan;  // the TTL after the last access
 
   if (__cache_lock_init(pCacheObj) != 0) {
     taosHashCleanup(pCacheObj->pHashTable);
+    free(pCacheObj->name);
     free(pCacheObj);
 
     uError("failed to init lock, reason:%s", strerror(errno));
@@ -694,12 +702,12 @@ void* taosCacheTimedRefresh(void *handle) {
 
   setThreadName("cacheRefresh");
 
-  const int32_t SLEEP_DURATION = 500; //500 ms
+  const int32_t SLEEP_DURATION_IN_MS = 500;
   int64_t count = 0;
   atexit(taosCacheRefreshWorkerUnexpectedStopped);
 
   while(1) {
-    taosMsleep(SLEEP_DURATION);
+    taosMsleep(SLEEP_DURATION_IN_MS);
     if (stopRefreshWorker) {
       goto _end;
     }