session: add session process node

Add a session process node that handles main thread tx and retransmit in
order to avoid having a polling input node.

Change-Id: I3357e987c023a84b533b32793e37ab4204420f64
Signed-off-by: Florin Coras <fcoras@cisco.com>

3 files changed, 81 insertions, 0 deletions

diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index 66cad2acff3..2697c26381e 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -1272,6 +1272,14 @@ listen_session_get_local_session_endpoint (stream_session_t * listener,
   return 0;
 }
 
+void
+session_flush_frames_main_thread (vlib_main_t * vm)
+{
+  ASSERT (vlib_get_thread_index () == 0);
+  vlib_process_signal_event_mt (vm, session_queue_process_node.index,
+				SESSION_Q_PROCESS_FLUSH_FRAMES, 0);
+}
+
 static clib_error_t *
 session_manager_main_enable (vlib_main_t * vm)
 {
@@ -1366,8 +1374,30 @@ void
 session_node_enable_disable (u8 is_en)
 {
   u8 state = is_en ? VLIB_NODE_STATE_POLLING : VLIB_NODE_STATE_DISABLED;
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  u8 have_workers = vtm->n_threads != 0;
+
   /* *INDENT-OFF* */
   foreach_vlib_main (({
+    if (have_workers && ii == 0)
+      {
+	vlib_node_set_state (this_vlib_main, session_queue_process_node.index,
+	                     state);
+	if (is_en)
+	  {
+	    vlib_node_t *n = vlib_get_node (this_vlib_main,
+	                                    session_queue_process_node.index);
+	    vlib_start_process (this_vlib_main, n->runtime_index);
+	  }
+	else
+	  {
+	    vlib_process_signal_event_mt (this_vlib_main,
+	                                  session_queue_process_node.index,
+	                                  SESSION_Q_PROCESS_STOP, 0);
+	  }
+
+	continue;
+      }
     vlib_node_set_state (this_vlib_main, session_queue_node.index,
                          state);
   }));
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index d6cc2cb3327..b24e22923f1 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -254,6 +254,10 @@ struct _session_manager_main
 
 extern session_manager_main_t session_manager_main;
 extern vlib_node_registration_t session_queue_node;
+extern vlib_node_registration_t session_queue_process_node;
+
+#define SESSION_Q_PROCESS_FLUSH_FRAMES	1
+#define SESSION_Q_PROCESS_STOP		2
 
 /*
  * Session manager function
@@ -594,6 +598,8 @@ int
 listen_session_get_local_session_endpoint (stream_session_t * listener,
 					   session_endpoint_t * sep);
 
+void session_flush_frames_main_thread (vlib_main_t * vm);
+
 always_inline u8
 session_manager_is_enabled ()
 {
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index 07cca6d46e7..46fc4dc8745 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -869,6 +869,51 @@ session_queue_exit (vlib_main_t * vm)
 
 VLIB_MAIN_LOOP_EXIT_FUNCTION (session_queue_exit);
 
+static uword
+session_queue_process (vlib_main_t * vm, vlib_node_runtime_t * rt,
+		       vlib_frame_t * f)
+{
+  f64 now, timeout = 1.0;
+  uword *event_data = 0;
+  uword event_type;
+
+  while (1)
+    {
+      vlib_process_wait_for_event_or_clock (vm, timeout);
+      now = vlib_time_now (vm);
+      event_type = vlib_process_get_events (vm, (uword **) & event_data);
+
+      switch (event_type)
+	{
+	case SESSION_Q_PROCESS_FLUSH_FRAMES:
+	  /* Flush the frames by updating all transports times */
+	  transport_update_time (now, 0);
+	  break;
+	case SESSION_Q_PROCESS_STOP:
+	  timeout = 100000.0;
+	  break;
+	case ~0:
+	  /* Timed out. Update time for all transports to trigger all
+	   * outstanding retransmits. */
+	  transport_update_time (now, 0);
+	  break;
+	}
+      vec_reset_length (event_data);
+    }
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (session_queue_process_node) =
+{
+  .function = session_queue_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "session-queue-process",
+  .state = VLIB_NODE_STATE_DISABLED,
+};
+/* *INDENT-ON* */
+
+
 /*
  * fd.io coding-style-patch-verification: ON
  *