diff --git a/examples/tcp_chat_server.c b/examples/tcp_chat_server.c
index 2fe688b04..edfa9b1c7 100644
--- a/examples/tcp_chat_server.c
+++ b/examples/tcp_chat_server.c
@@ -13,6 +13,11 @@
 #include "hbase.h"
 #include "list.h"
 
+// hloop_create_tcp_server
+// on_accept => join
+// on_recv => broadcast
+// on_close => leave
+
 typedef struct chatroom_s {
     hloop_t*            loop;
     hio_t*              listenio;
diff --git a/examples/tcp_echo_server.c b/examples/tcp_echo_server.c
index a497193b9..4c7572de9 100644
--- a/examples/tcp_echo_server.c
+++ b/examples/tcp_echo_server.c
@@ -11,6 +11,8 @@
 #include "hloop.h"
 #include "hsocket.h"
 
+// hloop_create_tcp_server -> on_accept -> hio_read -> on_recv -> hio_write
+
 static void on_close(hio_t* io) {
     printf("on_close fd=%d error=%d\n", hio_fd(io), hio_error(io));
 }
diff --git a/examples/tcp_proxy_server.c b/examples/tcp_proxy_server.c
index d8e93ca23..3f969ae45 100644
--- a/examples/tcp_proxy_server.c
+++ b/examples/tcp_proxy_server.c
@@ -1,7 +1,7 @@
 /*
  * tcp proxy server
  *
- * @test:         make examples
+ * @build:        make examples
  * @http_server:  bin/httpd -d
  * @proxy_server: bin/tcp_proxy_server 1234 127.0.0.1:8080
  *                bin/tcp_proxy_server 1234 www.baidu.com
@@ -18,12 +18,13 @@
 #include "hloop.h"
 #include "hsocket.h"
 
-// hloop_create_tcp_server => on_accept(connio) => proxyio = hloop_create_tcp_client
-// on_proxy_connect => hio_read(connio) hio_read(proxyio)
+// hloop_create_tcp_server
+// on_accept(connio) => proxyio = hloop_create_tcp_client
+// on_proxy_connect(proxyio) => hio_read(connio) hio_read(proxyio)
 // on_recv(connio) => hio_write(proxyio)
 // on_proxy_recv(proxyio) => hio_write(connio)
 // on_close(connio) => hio_close(proxyio)
-// on_proxy(proxyio) => hio_close(connio)
+// on_proxy_close(proxyio) => hio_close(connio)
 
 static char proxy_host[64] = "127.0.0.1";
 static int proxy_port = 80;