session: force session cleanups on app detach

Force transport and session cleanup on session detach if transport is
already closing. This should also avoid races between transport
initiated session cleanups and pending session control events.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I83a947a0c01f5af8ac70aa31fee660276f1d1c60

1 files changed, 23 insertions, 6 deletions

diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index e1a93a6e250..67e7ee39001 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -273,7 +273,7 @@ session_cleanup_notify (session_t * s, session_cleanup_ntf_t ntf)
   app_worker_t *app_wrk;
 
   app_wrk = app_worker_get_if_valid (s->app_wrk_index);
-  if (!app_wrk)
+  if (PREDICT_FALSE (!app_wrk))
     {
       if (ntf == SESSION_CLEANUP_TRANSPORT)
 	return;
@@ -1600,11 +1600,28 @@ void
 session_detach_app (session_t *s)
 {
   if (s->session_state < SESSION_STATE_TRANSPORT_CLOSING)
-    session_close (s);
-  else if (s->session_state < SESSION_STATE_TRANSPORT_CLOSED)
-    session_set_state (s, SESSION_STATE_APP_CLOSED);
-  else if (s->session_state < SESSION_STATE_CLOSED)
-    session_set_state (s, SESSION_STATE_CLOSED);
+    {
+      session_close (s);
+    }
+  else if (s->session_state < SESSION_STATE_TRANSPORT_DELETED)
+    {
+      transport_connection_t *tc;
+
+      /* Transport is closing but it's not yet deleted. Confirm close and
+       * subsequently detach transport from session and enqueue a session
+       * cleanup notification. Transport closed and cleanup notifications are
+       * going to be dropped by session layer apis */
+      transport_close (session_get_transport_proto (s), s->connection_index,
+		       s->thread_index);
+      tc = session_get_transport (s);
+      tc->s_index = SESSION_INVALID_INDEX;
+      session_set_state (s, SESSION_STATE_TRANSPORT_DELETED);
+      session_cleanup_notify (s, SESSION_CLEANUP_SESSION);
+    }
+  else
+    {
+      session_cleanup_notify (s, SESSION_CLEANUP_SESSION);
+    }
 
   s->flags |= SESSION_F_APP_CLOSED;
   s->app_wrk_index = APP_INVALID_INDEX;