fix #304

Signed-off-by: NH-ZeX <hzx20112012@gmail.com>

src/os/linux/src/os.c

@@ -223,29 +223,31 @@ 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
-   ********************************************************/
-  pthread_t      thread;
-  pthread_attr_t tattr;
-  if (pthread_attr_init(&tattr)) {
-    return -1;
-  }
+    /********************************************************
+     * Create SIGALRM loop thread
+     ********************************************************/
+    pthread_t thread;
+    pthread_attr_t tattr;
+    if (pthread_attr_init(&tattr)) {
+        return -1;
+    }
 
-  if (pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED)) {
-    return -1;
-  }
+    if (pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED)) {
+        return -1;
+    }
 
-  int *tms = (int *)malloc(sizeof(int));
-  *tms = ms;
-  if (pthread_create(&thread, &tattr, callback, (void *)tms)) {
-    return -1;
-  }
+    int *tms = (int *) malloc(sizeof(int));
+    *tms = ms;
+    if (pthread_create(&thread, &tattr, callback, (void *) tms)) {
+        free(tms);
+        return -1;
+    }
 
-  if (pthread_attr_destroy(&tattr)) {
-    return -1;
-  }
+    if (pthread_attr_destroy(&tattr)) {
+        return -1;
+    }
 
-  return 0;
+    return 0;
 }