Avoid read_cb after calling hio_close during hio_unpack

Author: ithewei

event/hevent.c

@@ -400,7 +400,7 @@ void hio_read_cb(hio_t* io, void* buf, int len) {
         hio_read_stop(io);
     }
 
-    if (io->read_cb) {
+    if (io->read_cb && !io->closed) {
         // printd("read_cb------\n");
         io->read_cb(io, buf, len);
         // printd("read_cb======\n");
@@ -418,7 +418,7 @@ void hio_read_cb(hio_t* io, void* buf, int len) {
 }
 
 void hio_write_cb(hio_t* io, const void* buf, int len) {
-    if (io->write_cb) {
+    if (io->write_cb  && !io->closed) {
         // printd("write_cb------\n");
         io->write_cb(io, buf, len);
         // printd("write_cb======\n");