Merge pull request #305 from H-ZeX/fix-mem-leak

fix memory leak in os/linux/src/os.c::taosInitTimer #304 

src/os/linux/src/os.c

@@ -223,6 +223,7 @@ int taosOpenUDServerSocket(char *ip, short port) {
   return sockFd;
 }
 
+// The callback functions MUST free the param pass to it after finishing use it.
 int taosInitTimer(void *(*callback)(void *), int ms) {
   /********************************************************
    * Create SIGALRM loop thread
@@ -237,9 +238,10 @@ int taosInitTimer(void *(*callback)(void *), int ms) {
       return -1;
   }
 
-  int *tms = (int *)malloc(sizeof(int));
+  int *tms = (int *) malloc(sizeof(int));
   *tms = ms;
-  if (pthread_create(&thread, &tattr, callback, (void *)tms)) {
+  if (pthread_create(&thread, &tattr, callback, (void *) tms)) {
+      free(tms);
       return -1;
   }