vcl: fix bidirectional tests (VPP-1455)

- add epoll dequeued events beyond maxevents to unhandled
- filter multiple epoll rx events

Change-Id: I618f5f02b19581473de891b3b59bb6a0faad10b5
Signed-off-by: Florin Coras <fcoras@cisco.com>
(cherry picked from commit aa27eb95b7ee3bb69b62166d5e418e973cbbdcfa)

3 files changed, 17 insertions, 13 deletions

diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 5975f15ac4f..d1a40b933a7 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -153,6 +153,7 @@ typedef struct
   /* Socket configuration state */
   u8 is_vep;
   u8 is_vep_session;
+  u8 has_rx_evt;
   u32 attr;
   u32 wait_cont_idx;
   vppcom_epoll_t vep;
diff --git a/src/vcl/vcl_test.h b/src/vcl/vcl_test.h
index 927110f55d2..9d28b262e3a 100644
--- a/src/vcl/vcl_test.h
+++ b/src/vcl/vcl_test.h
@@ -438,7 +438,7 @@ vcl_test_write (int fd, uint8_t * buf, uint32_t nbytes,
 	    {
 	      if (stats)
 		stats->tx_eagain++;
-	      continue;
+	      break;
 	    }
 	  else
 	    break;
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index df4ebde72eb..fad2ac98538 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -1293,13 +1293,14 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
   is_ct = vcl_session_is_ct (s);
   mq = is_ct ? s->our_evt_q : wrk->app_event_queue;
   rx_fifo = s->rx_fifo;
+  s->has_rx_evt = 0;
 
   if (svm_fifo_is_empty (rx_fifo))
     {
       if (is_nonblocking)
 	{
 	  svm_fifo_unset_event (rx_fifo);
-	  return VPPCOM_OK;
+	  return VPPCOM_EWOULDBLOCK;
 	}
       while (svm_fifo_is_empty (rx_fifo))
 	{
@@ -1385,13 +1386,14 @@ vppcom_session_read_segments (uint32_t session_handle,
   is_ct = vcl_session_is_ct (s);
   mq = is_ct ? s->our_evt_q : wrk->app_event_queue;
   rx_fifo = s->rx_fifo;
+  s->has_rx_evt = 0;
 
   if (svm_fifo_is_empty (rx_fifo))
     {
       if (is_nonblocking)
 	{
 	  svm_fifo_unset_event (rx_fifo);
-	  return VPPCOM_OK;
+	  return VPPCOM_EWOULDBLOCK;
 	}
       while (svm_fifo_is_empty (rx_fifo))
 	{
@@ -1551,7 +1553,8 @@ vppcom_session_write (uint32_t session_handle, void *buf, size_t n)
 	{
 	  svm_fifo_set_want_tx_evt (tx_fifo, 1);
 	  svm_msg_q_lock (mq);
-	  svm_msg_q_wait (mq);
+	  if (svm_msg_q_is_empty (mq))
+	    svm_msg_q_wait (mq);
 
 	  svm_msg_q_sub_w_lock (mq, &msg);
 	  e = svm_msg_q_msg_data (mq, &msg);
@@ -2303,11 +2306,12 @@ vcl_epoll_wait_handle_mq_event (vcl_worker_t * wrk, session_event_t * e,
       sid = e->fifo->client_session_index;
       session = vcl_session_get (wrk, sid);
       session_events = session->vep.ev.events;
-      if (!(EPOLLIN & session->vep.ev.events))
+      if (!(EPOLLIN & session->vep.ev.events) || session->has_rx_evt)
 	break;
       add_event = 1;
       events[*num_ev].events |= EPOLLIN;
       session_evt_data = session->vep.ev.data.u64;
+      session->has_rx_evt = 1;
       break;
     case FIFO_EVENT_APP_TX:
       sid = e->fifo->client_session_index;
@@ -2324,11 +2328,12 @@ vcl_epoll_wait_handle_mq_event (vcl_worker_t * wrk, session_event_t * e,
       session = vcl_ct_session_get_from_fifo (wrk, e->fifo, 0);
       sid = session->session_index;
       session_events = session->vep.ev.events;
-      if (!(EPOLLIN & session->vep.ev.events))
+      if (!(EPOLLIN & session->vep.ev.events) || session->has_rx_evt)
 	break;
       add_event = 1;
       events[*num_ev].events |= EPOLLIN;
       session_evt_data = session->vep.ev.data.u64;
+      session->has_rx_evt = 1;
       break;
     case SESSION_IO_EVT_CT_RX:
       session = vcl_ct_session_get_from_fifo (wrk, e->fifo, 1);
@@ -2452,15 +2457,13 @@ handle_dequeued:
     {
       msg = vec_elt_at_index (wrk->mq_msg_vector, i);
       e = svm_msg_q_msg_data (mq, msg);
-      vcl_epoll_wait_handle_mq_event (wrk, e, events, num_ev);
+      if (*num_ev < maxevents)
+	vcl_epoll_wait_handle_mq_event (wrk, e, events, num_ev);
+      else
+	vec_add1 (wrk->unhandled_evts_vector, *e);
       svm_msg_q_free_msg (mq, msg);
-      if (*num_ev == maxevents)
-	{
-	  i += 1;
-	  break;
-	}
     }
-  vec_delete (wrk->mq_msg_vector, i, 0);
+  vec_reset_length (wrk->mq_msg_vector);
 
   return *num_ev;
 }