[TD-6169]<fix>: windows dll client can not quit.

src/util/src/tcache.c

@@ -71,6 +71,7 @@ static pthread_once_t cacheThreadInit = PTHREAD_ONCE_INIT;
 static pthread_mutex_t guard          = PTHREAD_MUTEX_INITIALIZER;
 static SArray* pCacheArrayList        = NULL;
 static bool    stopRefreshWorker      = false;
+static bool    refreshWorkerStopped   = false;
 
 static void doInitRefreshThread(void) {
   pCacheArrayList = taosArrayInit(4, POINTER_BYTES);
@@ -538,6 +539,8 @@ void taosCacheCleanup(SCacheObj *pCacheObj) {
 
   // wait for the refresh thread quit before destroying the cache object.
   while(atomic_load_8(&pCacheObj->deleting) != 0) {
+    if (refreshWorkerUnexpectedStopped) return;    
+    if (refreshWorkerNormalStopped) break;    
     taosMsleep(50);
   }
 
@@ -676,6 +679,12 @@ static void doCacheRefresh(SCacheObj* pCacheObj, int64_t time, __cache_free_fn_t
   taosHashCondTraverse(pCacheObj->pHashTable, travHashTableFn, &sup);
 }
 
+void taosCacheRefreshWorkerUnexpectedStopped(void) {
+  if(!refreshWorkerNormalStopped) {
+    refreshWorkerUnexpectedStopped=true;
+  }
+}
+
 void* taosCacheTimedRefresh(void *handle) {
   assert(pCacheArrayList != NULL);
   uDebug("cache refresh thread starts");
@@ -685,6 +694,8 @@ void* taosCacheTimedRefresh(void *handle) {
   const int32_t SLEEP_DURATION = 500; //500 ms
   int64_t count = 0;
 
+  atexit(taosCacheRefreshWorkerUnexpectedStopped);
+
   while(1) {
     taosMsleep(SLEEP_DURATION);
     if (stopRefreshWorker) {
@@ -748,6 +759,7 @@ void* taosCacheTimedRefresh(void *handle) {
 
   pCacheArrayList = NULL;
   pthread_mutex_destroy(&guard);
+  refreshWorkerNormalStopped=true;
 
   uDebug("cache refresh thread quits");
   return NULL;