session tcp: handle rxt and acks as custom events

Type: feature

Control ack generation and retransmissions with session layer scheduler.

Change-Id: Iacdf9f84ab81f44851980aa45a83e75f29be2b7b
Signed-off-by: Florin Coras <fcoras@cisco.com>

6 files changed, 71 insertions, 8 deletions

diff --git a/src/vnet/session/application_local.c b/src/vnet/session/application_local.c
index 4a268c7d30b..7d8fb468f5a 100644
--- a/src/vnet/session/application_local.c
+++ b/src/vnet/session/application_local.c
@@ -467,7 +467,7 @@ format_ct_connection_id (u8 * s, va_list * args)
 }
 
 static int
-ct_custom_tx (void *session)
+ct_custom_tx (void *session, u32 max_burst_size)
 {
   session_t *s = (session_t *) session;
   if (session_has_transport (s))
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index 477215e3d34..1c8b7fb4be4 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -118,6 +118,31 @@ session_send_rpc_evt_to_thread (u32 thread_index, void *fp, void *rpc_args)
     }
 }
 
+void
+session_add_self_custom_tx_evt (transport_connection_t * tc, u8 has_prio)
+{
+  session_t *s;
+
+  s = session_get (tc->s_index, tc->thread_index);
+  ASSERT (s->thread_index == vlib_get_thread_index ());
+  if (!(s->flags & SESSION_F_CUSTOM_TX))
+    {
+      s->flags |= SESSION_F_CUSTOM_TX;
+      if (svm_fifo_set_event (s->tx_fifo))
+	{
+	  session_worker_t *wrk;
+	  session_evt_elt_t *elt;
+	  wrk = session_main_get_worker (tc->thread_index);
+	  if (has_prio)
+	    elt = session_evt_alloc_new (wrk);
+	  else
+	    elt = session_evt_alloc_old (wrk);
+	  elt->evt.session_index = tc->s_index;
+	  elt->evt.event_type = SESSION_IO_EVT_TX;
+	}
+    }
+}
+
 static void
 session_program_transport_close (session_t * s)
 {
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index a3f2a01929b..8f7bd6c999c 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -243,6 +243,26 @@ session_evt_add_pending_disconnects (session_worker_t * wrk,
 		       session_evt_pending_disconnects_head (wrk));
 }
 
+static inline session_evt_elt_t *
+session_evt_alloc_new (session_worker_t * wrk)
+{
+  session_evt_elt_t *elt;
+  elt = session_evt_elt_alloc (wrk);
+  clib_llist_add_tail (wrk->event_elts, evt_list, elt,
+		       pool_elt_at_index (wrk->event_elts, wrk->new_head));
+  return elt;
+}
+
+static inline session_evt_elt_t *
+session_evt_alloc_old (session_worker_t * wrk)
+{
+  session_evt_elt_t *elt;
+  elt = session_evt_elt_alloc (wrk);
+  clib_llist_add_tail (wrk->event_elts, evt_list, elt,
+		       pool_elt_at_index (wrk->event_elts, wrk->old_head));
+  return elt;
+}
+
 always_inline u8
 session_is_valid (u32 si, u8 thread_index)
 {
@@ -394,6 +414,8 @@ void session_send_rpc_evt_to_thread (u32 thread_index, void *fp,
 				     void *rpc_args);
 void session_send_rpc_evt_to_thread_force (u32 thread_index, void *fp,
 					   void *rpc_args);
+void session_add_self_custom_tx_evt (transport_connection_t * tc,
+				     u8 has_prio);
 transport_connection_t *session_get_transport (session_t * s);
 void session_get_endpoint (session_t * s, transport_endpoint_t * tep,
 			   u8 is_lcl);
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index 999776f02bd..1bb5cb2717f 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -618,7 +618,7 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
 				session_evt_elt_t * elt,
 				int *n_tx_packets, u8 peek_data)
 {
-  u32 next_index, next0, next1, *to_next, n_left_to_next;
+  u32 next_index, next0, next1, *to_next, n_left_to_next, max_burst;
   u32 n_trace, n_bufs_needed = 0, n_left, pbi;
   session_tx_context_t *ctx = &wrk->ctx;
   session_main_t *smm = &session_main;
@@ -637,6 +637,7 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
 
   next_index = smm->session_type_to_next[ctx->s->session_type];
   next0 = next1 = next_index;
+  max_burst = VLIB_FRAME_SIZE - *n_tx_packets;
 
   tp = session_get_transport_proto (ctx->s);
   ctx->transport_vft = transport_protocol_get_vft (tp);
@@ -649,6 +650,20 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
 	ctx->transport_vft->flush_data (ctx->tc);
     }
 
+  if (ctx->s->flags & SESSION_F_CUSTOM_TX)
+    {
+      u32 n_custom_tx;
+      ctx->s->flags &= ~SESSION_F_CUSTOM_TX;
+      n_custom_tx = ctx->transport_vft->custom_tx (ctx->tc, max_burst);
+      *n_tx_packets += n_custom_tx;
+      max_burst -= n_custom_tx;
+      if (!max_burst)
+	{
+	  session_evt_add_old (wrk, elt);
+	  return SESSION_TX_OK;
+	}
+    }
+
   ctx->snd_space = transport_connection_snd_space (ctx->tc,
 						   wrk->vm->clib_time.
 						   last_cpu_time,
@@ -664,8 +679,7 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
   svm_fifo_unset_event (ctx->s->tx_fifo);
 
   /* Check how much we can pull. */
-  session_tx_set_dequeue_params (vm, ctx, VLIB_FRAME_SIZE - *n_tx_packets,
-				 peek_data);
+  session_tx_set_dequeue_params (vm, ctx, max_burst, peek_data);
 
   if (PREDICT_FALSE (!ctx->max_len_to_snd))
     return SESSION_TX_NO_DATA;
@@ -823,7 +837,8 @@ session_tx_fifo_dequeue_internal (session_worker_t * wrk,
   if (PREDICT_FALSE (s->session_state >= SESSION_STATE_TRANSPORT_CLOSED))
     return 0;
   svm_fifo_unset_event (s->tx_fifo);
-  return transport_custom_tx (session_get_transport_proto (s), s);
+  return transport_custom_tx (session_get_transport_proto (s), s,
+			      VLIB_FRAME_SIZE - *n_tx_packets);
 }
 
 always_inline session_t *
diff --git a/src/vnet/session/session_types.h b/src/vnet/session/session_types.h
index 25b61166b11..9a5bc768808 100644
--- a/src/vnet/session/session_types.h
+++ b/src/vnet/session/session_types.h
@@ -142,6 +142,7 @@ typedef enum session_flags_
 {
   SESSION_F_RX_EVT = 1,
   SESSION_F_PROXY = (1 << 1),
+  SESSION_F_CUSTOM_TX = (1 << 2),
 } session_flags_t;
 
 typedef struct session_
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index 6e2feb02ba4..058a9aee34c 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -52,7 +52,7 @@ typedef struct _transport_proto_vft
   u32 (*tx_fifo_offset) (transport_connection_t * tc);
   void (*update_time) (f64 time_now, u8 thread_index);
   void (*flush_data) (transport_connection_t *tconn);
-  int (*custom_tx) (void *session);
+  int (*custom_tx) (void *session, u32 max_burst_size);
   int (*app_rx_evt) (transport_connection_t *tconn);
 
   /*
@@ -127,9 +127,9 @@ transport_get_half_open (transport_proto_t tp, u32 conn_index)
 }
 
 static inline int
-transport_custom_tx (transport_proto_t tp, void *s)
+transport_custom_tx (transport_proto_t tp, void *s, u32 max_burst_size)
 {
-  return tp_vfts[tp].custom_tx (s);
+  return tp_vfts[tp].custom_tx (s, max_burst_size);
 }
 
 static inline int