diff --git a/trunk/research/st/event.c b/trunk/research/st/event.c
index b824bc364..9747ee876 100644
--- a/trunk/research/st/event.c
+++ b/trunk/research/st/event.c
@@ -308,6 +308,8 @@ ST_HIDDEN void _st_epoll_dispatch(void)
         timeout = (int) (min_timeout / 1000);
     }
 
+    // TODO: WINLIN: remove it for bug introduced.
+    // @see: https://github.com/winlinvip/simple-rtmp-server/issues/193
     if (_st_epoll_data->pid != getpid()) {
         /* We probably forked, reinitialize epoll set */
         close(_st_epoll_data->epfd);
diff --git a/trunk/research/st/srs.c b/trunk/research/st/srs.c
index 6b9cb9346..fea655509 100644
--- a/trunk/research/st/srs.c
+++ b/trunk/research/st/srs.c
@@ -52,8 +52,8 @@ int sleep_test()
     srs_trace("sleep test: start");
     
     srs_trace("1. sleep...");
-    
     st_usleep(sleep_ms * 1000);
+    
     srs_trace("2. sleep ok");
     
     srs_trace("sleep test: end");