session: make app listener pool global

One less pointer chase when accepting sessions.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I20dbb21d15d4a703f76e3b12f04a6f5b5d2a3cd8
diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 5c8efe1..2c69138 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -31,10 +31,12 @@
 static app_listener_t *
 app_listener_alloc (application_t * app)
 {
+  app_main_t *am = &app_main;
   app_listener_t *app_listener;
-  pool_get (app->listeners, app_listener);
+
+  pool_get (am->listeners, app_listener);
   clib_memset (app_listener, 0, sizeof (*app_listener));
-  app_listener->al_index = app_listener - app->listeners;
+  app_listener->al_index = app_listener - am->listeners;
   app_listener->app_index = app->app_index;
   app_listener->session_index = SESSION_INVALID_INDEX;
   app_listener->local_index = SESSION_INVALID_INDEX;
@@ -43,19 +45,23 @@
 }
 
 app_listener_t *
-app_listener_get (application_t * app, u32 app_listener_index)
+app_listener_get (u32 app_listener_index)
 {
-  return pool_elt_at_index (app->listeners, app_listener_index);
+  app_main_t *am = &app_main;
+
+  return pool_elt_at_index (am->listeners, app_listener_index);
 }
 
 static void
 app_listener_free (application_t * app, app_listener_t * app_listener)
 {
+  app_main_t *am = &app_main;
+
   clib_bitmap_free (app_listener->workers);
   vec_free (app_listener->cl_listeners);
   if (CLIB_DEBUG)
     clib_memset (app_listener, 0xfa, sizeof (*app_listener));
-  pool_put (app->listeners, app_listener);
+  pool_put (am->listeners, app_listener);
 }
 
 session_handle_t
@@ -64,24 +70,14 @@
   return al->ls_handle;
 }
 
-app_listener_t *
-app_listener_get_w_session (session_t * ls)
-{
-  application_t *app;
-
-  app = application_get_if_valid (ls->app_index);
-  if (!app)
-    return 0;
-  return app_listener_get (app, ls->al_index);
-}
-
 session_handle_t
 app_listen_session_handle (session_t * ls)
 {
   app_listener_t *al;
-  al = app_listener_get_w_session (ls);
-  if (!al)
+  /* TODO(fcoras): quic session handles */
+  if (ls->al_index == SESSION_INVALID_INDEX)
     return listen_session_get_handle (ls);
+  al = app_listener_get (ls->al_index);
   return al->ls_handle;
 }
 
@@ -92,7 +88,7 @@
   ls = session_get_from_handle_if_valid (handle);
   if (!ls)
     return 0;
-  return app_listener_get_w_session (ls);
+  return app_listener_get (ls->al_index);
 }
 
 app_listener_t *
@@ -113,7 +109,7 @@
       if (handle != SESSION_INVALID_HANDLE)
 	{
 	  ls = listen_session_get_from_handle (handle);
-	  return app_listener_get_w_session (ls);
+	  return app_listener_get (ls->al_index);
 	}
     }
 
@@ -123,7 +119,7 @@
   if (handle != SESSION_INVALID_HANDLE)
     {
       ls = listen_session_get_from_handle (handle);
-      return app_listener_get_w_session ((session_t *) ls);
+      return app_listener_get (ls->al_index);
     }
 
   /*
@@ -145,7 +141,7 @@
 	  if (handle != SESSION_INVALID_HANDLE)
 	    {
 	      ls = listen_session_get_from_handle (handle);
-	      return app_listener_get_w_session ((session_t *) ls);
+	      return app_listener_get (ls->al_index);
 	    }
 	}
     }
@@ -182,7 +178,6 @@
       local_st = session_type_from_proto_and_ip (TRANSPORT_PROTO_NONE,
 						 sep->is_ip4);
       ls = listen_session_alloc (0, local_st);
-      ls->app_index = app->app_index;
       ls->app_wrk_index = sep->app_wrk_index;
       lh = session_handle (ls);
 
@@ -195,7 +190,7 @@
 	}
 
       ls = session_get_from_handle (lh);
-      app_listener = app_listener_get (app, al_index);
+      app_listener = app_listener_get (al_index);
       app_listener->local_index = ls->session_index;
       app_listener->ls_handle = lh;
       ls->al_index = al_index;
@@ -214,7 +209,6 @@
        * build it's own specific listening connection.
        */
       ls = listen_session_alloc (0, st);
-      ls->app_index = app->app_index;
       ls->app_wrk_index = sep->app_wrk_index;
 
       /* Listen pool can be reallocated if the transport is
@@ -229,7 +223,7 @@
 	  return rv;
 	}
       ls = listen_session_get_from_handle (lh);
-      app_listener = app_listener_get (app, al_index);
+      app_listener = app_listener_get (al_index);
       app_listener->session_index = ls->session_index;
       app_listener->ls_handle = lh;
       ls->al_index = al_index;
@@ -291,8 +285,9 @@
 }
 
 static app_worker_t *
-app_listener_select_worker (application_t * app, app_listener_t * al)
+app_listener_select_worker (app_listener_t *al)
 {
+  application_t *app;
   u32 wrk_index;
 
   app = application_get (al->app_index);
@@ -1017,12 +1012,10 @@
 app_worker_t *
 application_listener_select_worker (session_t * ls)
 {
-  application_t *app;
   app_listener_t *al;
 
-  app = application_get (ls->app_index);
-  al = app_listener_get (app, ls->al_index);
-  return app_listener_select_worker (app, al);
+  al = app_listener_get (ls->al_index);
+  return app_listener_select_worker (al);
 }
 
 always_inline u32
@@ -1054,11 +1047,9 @@
 app_listener_select_wrk_cl_session (session_t *ls, session_dgram_hdr_t *hdr)
 {
   u32 wrk_map_index = 0;
-  application_t *app;
   app_listener_t *al;
 
-  app = application_get (ls->app_index);
-  al = app_listener_get (app, ls->al_index);
+  al = app_listener_get (ls->al_index);
   /* Crude test to check if only worker 0 is set */
   if (al->workers[0] != 1)
     {
@@ -1548,7 +1539,7 @@
   if (!app)
     return SESSION_E_NOAPP;
 
-  app_listener = app_listener_get (app, s->al_index);
+  app_listener = app_listener_get (s->al_index);
 
   /* Only remove from lb for now */
   app_listener->workers = clib_bitmap_set (app_listener->workers,
diff --git a/src/vnet/session/application.h b/src/vnet/session/application.h
index 7c63b90..22896b1 100644
--- a/src/vnet/session/application.h
+++ b/src/vnet/session/application.h
@@ -151,9 +151,6 @@
 
   u16 proxied_transports;
 
-  /** Pool of listeners for the app */
-  app_listener_t *listeners;
-
   /** Preferred tls engine */
   u8 tls_engine;
 
@@ -200,6 +197,9 @@
    */
   application_t *app_pool;
 
+  /** Pool of app listeners */
+  app_listener_t *listeners;
+
   /**
    * Hash table of apps by api client index
    */
@@ -248,7 +248,7 @@
 #define APP_NS_INVALID_INDEX ((u32)~0)
 #define APP_INVALID_SEGMENT_MANAGER_INDEX ((u32) ~0)
 
-app_listener_t *app_listener_get (application_t * app, u32 al_index);
+app_listener_t *app_listener_get (u32 al_index);
 int app_listener_alloc_and_init (application_t * app,
 				 session_endpoint_cfg_t * sep,
 				 app_listener_t ** listener);
@@ -281,7 +281,6 @@
  * @return		pointer to app listener or 0
  */
 app_listener_t *app_listener_get_w_handle (session_handle_t handle);
-app_listener_t *app_listener_get_w_session (session_t * ls);
 session_t *app_listener_get_session (app_listener_t * al);
 session_t *app_listener_get_local_session (app_listener_t * al);
 session_t *app_listener_get_wrk_cl_session (app_listener_t *al, u32 wrk_index);
diff --git a/src/vnet/session/application_local.c b/src/vnet/session/application_local.c
index 8fd3d44..8c6cf8a 100644
--- a/src/vnet/session/application_local.c
+++ b/src/vnet/session/application_local.c
@@ -995,7 +995,7 @@
     goto global_scope;
 
   ll = listen_session_get_from_handle (lh);
-  al = app_listener_get_w_session (ll);
+  al = app_listener_get (ll->al_index);
 
   /*
    * Break loop if rule in local table points to connecting app. This
@@ -1024,8 +1024,12 @@
   ll = session_lookup_listener_wildcard (table_index, sep);
 
   /* Avoid connecting app to own listener */
-  if (ll && ll->app_index != app->app_index)
-    return ct_connect (app_wrk, ll, sep_ext);
+  if (ll)
+    {
+      al = app_listener_get (ll->al_index);
+      if (al->app_index != app->app_index)
+	return ct_connect (app_wrk, ll, sep_ext);
+    }
 
   /* Failed to connect but no error */
   return SESSION_E_LOCAL_CONNECT;
diff --git a/src/vnet/session/application_worker.c b/src/vnet/session/application_worker.c
index ea5a4db..5a74028 100644
--- a/src/vnet/session/application_worker.c
+++ b/src/vnet/session/application_worker.c
@@ -194,7 +194,7 @@
   app_listener_t *al;
   session_t *s;
 
-  al = app_listener_get_w_session (ls);
+  al = app_listener_get (ls->al_index);
   sm = app_worker_get_listen_segment_manager (app_wrk, ls);
   lsh = session_handle (ls);
 
@@ -230,7 +230,7 @@
   app_listener_t *al;
   session_t *s;
 
-  al = app_listener_get_w_session (ls);
+  al = app_listener_get (ls->al_index);
 
   s = app_listener_get_wrk_cl_session (al, app_wrk->wrk_map_index);
   segment_manager_dealloc_fifos (s->rx_fifo, s->tx_fifo);
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index 0d2e1b1..7968182 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -209,7 +209,7 @@
   clib_memset (s, 0, sizeof (*s));
   s->session_index = s - wrk->sessions;
   s->thread_index = thread_index;
-  s->app_index = APP_INVALID_INDEX;
+  s->al_index = APP_INVALID_INDEX;
 
   return s;
 }
@@ -318,7 +318,7 @@
 	}
       /* Migrated transports are no longer half-opens */
       transport_cleanup (session_get_transport_proto (ho),
-			 ho->connection_index, ho->app_index /* overloaded */);
+			 ho->connection_index, ho->al_index /* overloaded */);
     }
   else if (ho->session_state != SESSION_STATE_TRANSPORT_DELETED)
     {
@@ -410,8 +410,8 @@
       return -1;
     }
   ho->connection_index = tc->c_index;
-  /* Overload app index for half-open with new thread */
-  ho->app_index = tc->thread_index;
+  /* Overload al_index for half-open with new thread */
+  ho->al_index = tc->thread_index;
   return 0;
 }
 
diff --git a/src/vnet/session/session_types.h b/src/vnet/session/session_types.h
index be3f9ff..8ec972d 100644
--- a/src/vnet/session/session_types.h
+++ b/src/vnet/session/session_types.h
@@ -219,17 +219,14 @@
   /** Index of the transport connection associated to the session */
   u32 connection_index;
 
-  /** Index of application that owns the listener. Set only if a listener */
-  u32 app_index;
+  /** App listener index in app's listener pool if a listener */
+  u32 al_index;
 
   union
   {
     /** Parent listener session index if the result of an accept */
     session_handle_t listener_handle;
 
-    /** App listener index in app's listener pool if a listener */
-    u32 al_index;
-
     /** Index in app worker's half-open table if a half-open */
     u32 ho_index;
   };