VCL IOEvent external API callback

Change-Id: I417357b00c43b27872aa3f681335bdc1ef574eca
Signed-off-by: Keith Burns (alagalah) <alagalah@gmail.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

6 files changed, 367 insertions, 90 deletions

diff --git a/src/vcl/sock_test.h b/src/vcl/sock_test.h
index f9f5c7070b2..26dc3f1e653 100644
--- a/src/vcl/sock_test.h
+++ b/src/vcl/sock_test.h
@@ -65,6 +65,7 @@ typedef enum
 typedef struct  __attribute__ ((packed))
 {
   uint32_t magic;
+  uint32_t seq_num;
   uint32_t test;
   uint32_t ctrl_handle;
   uint32_t num_test_sockets;
@@ -215,6 +216,7 @@ sock_test_cfg_dump (sock_test_cfg_t * cfg, uint8_t is_client)
   printf ("  test config (%p):\n"
           SOCK_TEST_SEPARATOR_STRING
 	  "                 magic:  0x%08x\n"
+	  "               seq_num:  0x%08x\n"
 	  "%-5s             test:  %s (%d)\n"
 	  "           ctrl handle:  %d (0x%x)\n"
 	  "%-5s num test sockets:  %u (0x%08x)\n"
@@ -224,7 +226,7 @@ sock_test_cfg_dump (sock_test_cfg_t * cfg, uint8_t is_client)
 	  "%-5s       num writes:  %lu (0x%08lx)\n"
 	  "       client tx bytes:  %lu (0x%08lx)\n"
           SOCK_TEST_SEPARATOR_STRING,
-	  (void *) cfg, cfg->magic,
+	  (void *) cfg, cfg->magic, cfg->seq_num,
           is_client && (cfg->test == SOCK_TEST_TYPE_UNI) ?
           "'"SOCK_TEST_TOKEN_RUN_UNI"'" :
           is_client && (cfg->test == SOCK_TEST_TYPE_BI) ?
diff --git a/src/vcl/sock_test_client.c b/src/vcl/sock_test_client.c
index 1ed4b89a3b1..e88b2b91b9d 100644
--- a/src/vcl/sock_test_client.c
+++ b/src/vcl/sock_test_client.c
@@ -37,6 +37,7 @@ typedef struct
 #endif
   struct sockaddr_storage server_addr;
   uint32_t server_addr_size;
+  uint32_t cfg_seq_num;
   sock_test_socket_t ctrl_socket;
   sock_test_socket_t *test_socket;
   uint32_t num_test_sockets;
@@ -57,12 +58,18 @@ sock_test_cfg_sync (sock_test_socket_t * socket)
   if (socket->cfg.verbose)
     sock_test_cfg_dump (&socket->cfg, 1 /* is_client */ );
 
+  ctrl->cfg.seq_num = ++scm->cfg_seq_num;
+  if (socket->cfg.verbose)
+    {
+      printf ("CLIENT (fd %d): Sending config sent to server.\n", socket->fd);
+      sock_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+    }
   tx_bytes = sock_test_write (socket->fd, (uint8_t *) & ctrl->cfg,
 			      sizeof (ctrl->cfg), NULL, ctrl->cfg.verbose);
   if (tx_bytes < 0)
     {
-      fprintf (stderr, "CLIENT: ERROR: write test cfg failed (%d)!\n",
-	       tx_bytes);
+      fprintf (stderr, "CLIENT (fd %d): ERROR: write test cfg failed (%d)!\n",
+	       socket->fd, tx_bytes);
       return tx_bytes;
     }
 
@@ -73,22 +80,34 @@ sock_test_cfg_sync (sock_test_socket_t * socket)
 
   if (rl_cfg->magic != SOCK_TEST_CFG_CTRL_MAGIC)
     {
-      fprintf (stderr, "CLIENT: ERROR: Bad server reply cfg -- aborting!\n");
+      fprintf (stderr, "CLIENT (fd %d): ERROR: Bad server reply cfg "
+	       "-- aborting!\n", socket->fd);
       return -1;
     }
-  if (socket->cfg.verbose)
-    {
-      printf ("CLIENT (fd %d): Got config back from server.\n", socket->fd);
-      sock_test_cfg_dump (rl_cfg, 1 /* is_client */ );
-    }
   if ((rx_bytes != sizeof (sock_test_cfg_t))
       || !sock_test_cfg_verify (rl_cfg, &ctrl->cfg))
     {
-      fprintf (stderr, "CLIENT: ERROR: Invalid config received "
-	       "from server -- aborting!\n");
-      sock_test_cfg_dump (rl_cfg, 1 /* is_client */ );
+      fprintf (stderr, "CLIENT (fd %d): ERROR: Invalid config received "
+	       "from server!\n", socket->fd);
+      if (rx_bytes != sizeof (sock_test_cfg_t))
+	{
+	  fprintf (stderr, "\tRx bytes %d != cfg size %lu\n",
+		   rx_bytes, sizeof (sock_test_cfg_t));
+	}
+      else
+	{
+	  sock_test_cfg_dump (rl_cfg, 1 /* is_client */ );
+	  fprintf (stderr, "CLIENT (fd %d): Valid config sent to server.\n",
+		   socket->fd);
+	  sock_test_cfg_dump (&ctrl->cfg, 1 /* is_client */ );
+	}
       return -1;
     }
+  else if (socket->cfg.verbose)
+    {
+      printf ("CLIENT (fd %d): Got config back from server.\n", socket->fd);
+      sock_test_cfg_dump (rl_cfg, 1 /* is_client */ );
+    }
   ctrl->cfg.ctrl_handle = ((ctrl->cfg.ctrl_handle == ~0) ?
 			   rl_cfg->ctrl_handle : ctrl->cfg.ctrl_handle);
 
@@ -118,7 +137,8 @@ echo_test_client ()
       tsock = &scm->test_socket[n];
       tsock->cfg = ctrl->cfg;
       sock_test_socket_buf_alloc (tsock);
-      sock_test_cfg_sync (tsock);
+      if (sock_test_cfg_sync (tsock))
+	return;
 
       memcpy (tsock->txbuf, ctrl->txbuf, nbytes);
       memset (&tsock->stats, 0, sizeof (tsock->stats));
diff --git a/src/vcl/vcl_event.c b/src/vcl/vcl_event.c
index d8bd8c74e36..dafa2500d1d 100644
--- a/src/vcl/vcl_event.c
+++ b/src/vcl/vcl_event.c
@@ -59,10 +59,10 @@ vce_generate_event (vce_event_thread_t *evt, u32 ev_idx)
 }
 
 void
-vce_clear_event (vce_event_thread_t *evt, vce_event_t *ev)
+vce_clear_event (vce_event_thread_t *evt, u32 ev_idx)
 {
   clib_spinlock_lock (&(evt->events_lockp));
-  pool_put (evt->vce_events, ev);
+  pool_put_index (evt->vce_events, ev_idx);
   clib_spinlock_unlock (&(evt->events_lockp));
 }
 
@@ -70,11 +70,10 @@ vce_event_t *
 vce_get_event_from_index(vce_event_thread_t *evt, u32 ev_idx)
 {
   vce_event_t *ev = 0;
+  /* Assumes caller has obtained the spinlock (evt->events_lockp) */
 
-  clib_spinlock_lock (&(evt->events_lockp));
   if ( ! pool_is_free_index (evt->vce_events, ev_idx))
     ev = pool_elt_at_index (evt->vce_events, ev_idx);
-  clib_spinlock_unlock (&(evt->events_lockp));
 
   return ev;
 }
@@ -96,7 +95,7 @@ vce_get_event_handler (vce_event_thread_t *evt, vce_event_key_t *evk)
 
 vce_event_handler_reg_t *
 vce_register_handler (vce_event_thread_t *evt, vce_event_key_t *evk,
-		      vce_event_callback_t cb, void *cb_args)
+                      vce_event_callback_t cb, void *cb_args)
 {
   vce_event_handler_reg_t *handler;
   vce_event_handler_reg_t *old_handler = 0;
@@ -115,25 +114,25 @@ vce_register_handler (vce_event_thread_t *evt, vce_event_key_t *evk,
       /* If we are just re-registering, ignore and move on
        * else store the old handler_fn for unregister to re-instate */
       if (old_handler->handler_fn == cb)
-	{
+        {
 
-	  clib_spinlock_unlock (&evt->handlers_lockp);
+          clib_spinlock_unlock (&evt->handlers_lockp);
 
-	  /* Signal event thread that a handler exists in case any
-	   * recycled events requiring this handler are pending */
-	  pthread_mutex_lock (&(evt->generator_lock));
-	  pthread_cond_signal (&(evt->generator_cond));
-	  pthread_mutex_unlock (&(evt->generator_lock));
-	  return old_handler;
-	}
+          /* Signal event thread that a handler exists in case any
+           * recycled events requiring this handler are pending */
+          pthread_mutex_lock (&(evt->generator_lock));
+          pthread_cond_signal (&(evt->generator_cond));
+          pthread_mutex_unlock (&(evt->generator_lock));
+          return old_handler;
+        }
     }
 
   pool_get (evt->vce_event_handlers, handler);
   handler_index = (u32) (handler - evt->vce_event_handlers);
 
   handler->handler_fn = cb;
-  handler->replaced_handler_idx = (p) ? p[0] : ~0;
-  handler->ev_idx = ~0; //This will be set by the event thread if event happens
+  handler->replaced_handler_idx = (u32) ((p) ? p[0] : ~0);
+  handler->ev_idx = (u32) ~0; //This will be set by the event thread if event happens
   handler->evk = evk->as_u64;
   handler->handler_fn_args = cb_args;
 
@@ -210,61 +209,64 @@ vce_event_thread_fn (void *arg)
   u32 ev_idx;
   vce_event_handler_reg_t *handler;
   uword *p;
+  u32 recycle_count = 0;
 
   pthread_mutex_lock (&(evt->generator_lock));
-  clib_spinlock_lock (&(evt->events_lockp));
-  evt->recycle_event = 1; // Used for recycling events with no handlers
-  clib_spinlock_unlock (&(evt->events_lockp));
-
-  do
+  while (1)
     {
-      while ( (clib_fifo_elts (evt->event_index_fifo) == 0) ||
-	      evt->recycle_event)
-	{
-          clib_spinlock_lock (&(evt->events_lockp));
-	  evt->recycle_event = 0;
-          clib_spinlock_unlock (&(evt->events_lockp));
-	  pthread_cond_wait (&(evt->generator_cond),
-			     &(evt->generator_lock));
-	}
+      uword fifo_depth = clib_fifo_elts (evt->event_index_fifo);
+      while ((fifo_depth == 0) || (recycle_count == fifo_depth))
+        {
+          recycle_count = 0;
+          pthread_cond_wait (&(evt->generator_cond), &(evt->generator_lock));
+          fifo_depth = clib_fifo_elts (evt->event_index_fifo);
+        }
 
       /* Remove event */
       clib_spinlock_lock (&(evt->events_lockp));
-
       clib_fifo_sub1 (evt->event_index_fifo, ev_idx);
-      ev = pool_elt_at_index (evt->vce_events, ev_idx);
-
+      ev = vce_get_event_from_index (evt, ev_idx);
       ASSERT(ev);
-
+      if (recycle_count && ev->recycle)
+        {
+          clib_fifo_add1 (evt->event_index_fifo, ev_idx);
+          clib_spinlock_unlock (&(evt->events_lockp));
+          continue;
+        }
       clib_spinlock_lock (&evt->handlers_lockp);
 
       p = hash_get (evt->handlers_index_by_event_key, ev->evk.as_u64);
       if (!p)
-	{
-	  /* If an event falls in the woods, and there is no handler to hear it,
-	   * does it make any sound?
-	   * I don't know either, so lets try recycling the event */
-	  clib_fifo_add1 (evt->event_index_fifo, ev_idx);
-	  evt->recycle_event = 1;
+        {
+          /* If an event falls in the woods, and there is no handler to hear it,
+           * does it make any sound?
+           * I don't know either, so lets biff the event */
+          pool_put(evt->vce_events, ev);
           clib_spinlock_unlock (&(evt->events_lockp));
-	  clib_spinlock_unlock (&evt->handlers_lockp);
+          clib_spinlock_unlock (&evt->handlers_lockp);
           pthread_mutex_unlock (&(evt->generator_lock));
-	}
+        }
       else
         {
+          u32 evt_recycle = ev->recycle;
           handler = pool_elt_at_index (evt->vce_event_handlers, p[0]);
           handler->ev_idx = ev_idx;
+          ev->recycle = 0;
 
           clib_spinlock_unlock (&(evt->events_lockp));
           clib_spinlock_unlock (&evt->handlers_lockp);
           pthread_mutex_unlock (&(evt->generator_lock));
 
           (handler->handler_fn)(handler);
+
+          clib_spinlock_lock (&(evt->events_lockp));
+          ev = vce_get_event_from_index (evt, ev_idx);
+          recycle_count += (!evt_recycle && ev && ev->recycle) ? 1 : 0;
+          clib_spinlock_unlock(&(evt->events_lockp));
         }
 
       pthread_mutex_lock (&(evt->generator_lock));
     }
-  while (1);
   return NULL;
 }
 
@@ -281,5 +283,6 @@ vce_start_event_thread (vce_event_thread_t *evt, u8 max_events)
   clib_spinlock_init (&(evt->handlers_lockp));
 
   return pthread_create (&(evt->thread), NULL /* attr */ ,
-			 vce_event_thread_fn, evt);
+                         vce_event_thread_fn, evt);
 }
+
diff --git a/src/vcl/vcl_event.h b/src/vcl/vcl_event.h
index f2a85a0f1d2..21884665075 100644
--- a/src/vcl/vcl_event.h
+++ b/src/vcl/vcl_event.h
@@ -39,8 +39,8 @@ typedef union vce_event_key_
 typedef struct vce_event_
 {
   vce_event_key_t evk;
-  u32 refcnt;
-  void *data;
+  u32 recycle;
+  u64 data[2]; // Hard code size to avoid allocator thrashing.
 } vce_event_t;
 
 typedef void (*vce_event_callback_t) (void *reg /*vce_event_handler_reg_t* */);
@@ -87,9 +87,9 @@ int vce_generate_event (vce_event_thread_t *evt, u32 ev_idx);
  * - removes event from event_pool
  *
  * @param evt - vce_event_thread_t - event system state
- * @param ev  - vce_event_t - event to remove
+ * @param ev_idx  - u32 - index of event to remove
  */
-void vce_clear_event (vce_event_thread_t *evt, vce_event_t *ev);
+void vce_clear_event (vce_event_thread_t *evt, u32 ev_idx);
 
 /**
  * @brief vce_get_event_from_index()
@@ -102,6 +102,20 @@ void vce_clear_event (vce_event_thread_t *evt, vce_event_t *ev);
 vce_event_t * vce_get_event_from_index(vce_event_thread_t *evt, u32 ev_idx);
 
 /**
+ * @brief vce_get_event_data()
+ *
+ * @param ev - vce_event_t * - event
+ * @param data_size - u32 - required size of data
+ *
+ * @return vce_event_t *
+ */
+always_inline void * vce_get_event_data(vce_event_t *ev, u32 data_size)
+{
+	ASSERT(sizeof(ev->data) >= data_size);
+	return (&ev->data);
+}
+
+/**
  * @brief vce_get_event_handler()
  * - returns handler if exists or 0
  * @param evt - vce_event_thread_t - event system state
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index cab2f6039e9..a66926d8731 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -195,9 +195,12 @@ typedef enum vcl_event_id_
 {
   VCL_EVENT_INVALID_EVENT,
   VCL_EVENT_CONNECT_REQ_ACCEPTED,
+  VCL_EVENT_IOEVENT_RX_FIFO,
+  VCL_EVENT_IOEVENT_TX_FIFO,
   VCL_EVENT_N_EVENTS
 } vcl_event_id_t;
 
+
 typedef struct vce_event_connect_request_
 {
   u32 accepted_session_index;
@@ -210,6 +213,22 @@ typedef struct vppcom_session_listener
   void *user_cb_data;
 } vppcom_session_listener_t;
 
+typedef struct vppcom_session_ioevent_
+{
+  vppcom_session_ioevent_cb user_cb;
+  void *user_cb_data;
+} vppcom_session_ioevent_t;
+
+typedef struct vppcom_session_io_thread_
+{
+  pthread_t thread;
+  pthread_mutex_t vce_io_lock;
+  pthread_cond_t vce_io_cond;
+  u32 *active_session_indexes;	//pool
+  vppcom_session_ioevent_t *ioevents;	//pool
+  clib_spinlock_t io_sessions_lockp;
+} vppcom_session_io_thread_t;
+
 typedef struct vppcom_main_t_
 {
   u8 init;
@@ -254,6 +273,9 @@ typedef struct vppcom_main_t_
   /* Event thread */
   vce_event_thread_t event_thread;
 
+  /* IO thread */
+  vppcom_session_io_thread_t session_io_thread;
+
   /* VPP Event-logger */
   elog_main_t elog_main;
   elog_track_t elog_track;
@@ -364,6 +386,9 @@ vppcom_session_state_str (session_state_t state)
 /*
  * VPPCOM Utility Functions
  */
+
+
+
 static inline int
 vppcom_session_at_index (u32 session_index, session_t * volatile *sess)
 {
@@ -379,6 +404,81 @@ vppcom_session_at_index (u32 session_index, session_t * volatile *sess)
   return VPPCOM_OK;
 }
 
+void *
+vppcom_session_io_thread_fn (void *arg)
+{
+  vppcom_session_io_thread_t *evt = (vppcom_session_io_thread_t *) arg;
+  u32 *session_indexes = 0, *session_index;
+  int i, rv;
+  u32 bytes = 0;
+  session_t *session;
+
+  while (1)
+    {
+      vec_reset_length (session_indexes);
+      clib_spinlock_lock (&evt->io_sessions_lockp);
+      pool_foreach (session_index, evt->active_session_indexes, (
+								  {
+								  vec_add1
+								  (session_indexes,
+								   *session_index);
+								  }
+		    ));
+      clib_spinlock_unlock (&evt->io_sessions_lockp);
+      if (session_indexes)
+	{
+	  for (i = 0; i < vec_len (session_indexes); ++i)
+	    {
+	      VCL_LOCK_AND_GET_SESSION (session_indexes[i], &session);
+	      bytes = svm_fifo_max_dequeue (session->rx_fifo);
+	      clib_spinlock_unlock (&vcm->sessions_lockp);
+
+	      if (bytes)
+		{
+		  vppcom_ioevent_t *eio;
+		  vce_event_t *ev;
+		  u32 ev_idx;
+
+		  clib_spinlock_lock (&vcm->event_thread.events_lockp);
+
+		  pool_get (vcm->event_thread.vce_events, ev);
+		  ev_idx = (u32) (ev - vcm->event_thread.vce_events);
+		  eio = vce_get_event_data (ev, sizeof (*eio));
+		  ev->evk.eid = VCL_EVENT_IOEVENT_RX_FIFO;
+		  ev->evk.session_index = session_indexes[i];
+		  eio->bytes = bytes;
+		  eio->session_index = session_indexes[i];
+
+		  clib_spinlock_unlock (&vcm->event_thread.events_lockp);
+
+		  rv = vce_generate_event (&vcm->event_thread, ev_idx);
+		}
+	    }
+	}
+      struct timespec ts;
+      ts.tv_sec = 0;
+      ts.tv_nsec = 1000000;	/* 1 millisecond */
+      nanosleep (&ts, NULL);
+    }
+done:
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+  return NULL;
+}
+
+int
+vppcom_start_io_event_thread (vppcom_session_io_thread_t * evt,
+			      u8 max_sessions)
+{
+  pthread_cond_init (&(evt->vce_io_cond), NULL);
+  pthread_mutex_init (&(evt->vce_io_lock), NULL);
+
+  clib_spinlock_init (&(evt->io_sessions_lockp));
+
+  return pthread_create (&(evt->thread), NULL /* attr */ ,
+			 vppcom_session_io_thread_fn, evt);
+}
+
+
 static inline void
 vppcom_session_table_add_listener (u64 listener_handle, u32 value)
 {
@@ -462,6 +562,32 @@ vppcom_send_accept_session_reply (u64 handle, u32 context, int retval)
  */
 
 void
+vce_registered_ioevent_handler_fn (void *arg)
+{
+  vce_event_handler_reg_t *reg = (vce_event_handler_reg_t *) arg;
+  vppcom_ioevent_t *eio;
+  vce_event_t *ev;
+  u32 ioevt_ndx = (u64) (reg->handler_fn_args);
+  vppcom_session_ioevent_t *ioevent, ioevent_;
+
+  clib_spinlock_lock (&(vcm->event_thread.events_lockp));
+  ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
+  eio = vce_get_event_data (ev, sizeof (*eio));
+  clib_spinlock_unlock (&(vcm->event_thread.events_lockp));
+
+  clib_spinlock_lock (&vcm->session_io_thread.io_sessions_lockp);
+  ioevent = pool_elt_at_index (vcm->session_io_thread.ioevents, ioevt_ndx);
+  ioevent_ = *ioevent;
+  clib_spinlock_unlock (&vcm->session_io_thread.io_sessions_lockp);
+  (ioevent_.user_cb) (eio, ioevent_.user_cb_data);
+  vce_clear_event (&vcm->event_thread, reg->ev_idx);
+  return;
+
+  /*TODO - Unregister check in close for this listener */
+
+}
+
+void
 vce_registered_listener_connect_handler_fn (void *arg)
 {
   vce_event_handler_reg_t *reg = (vce_event_handler_reg_t *) arg;
@@ -475,12 +601,12 @@ vce_registered_listener_connect_handler_fn (void *arg)
   vppcom_session_listener_t *session_listener =
     (vppcom_session_listener_t *) reg->handler_fn_args;
 
+  clib_spinlock_lock (&(vcm->event_thread.events_lockp));
   ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
-
-  ecr = (vce_event_connect_request_t *) ev->data;
+  ecr = vce_get_event_data (ev, sizeof (*ecr));
+  clib_spinlock_unlock (&(vcm->event_thread.events_lockp));
   VCL_LOCK_AND_GET_SESSION (ecr->accepted_session_index, &new_session);
 
-
   ep.is_ip4 = new_session->peer_addr.is_ip4;
   ep.port = new_session->peer_port;
   if (new_session->peer_addr.is_ip4)
@@ -498,8 +624,18 @@ vce_registered_listener_connect_handler_fn (void *arg)
   (session_listener->user_cb) (ecr->accepted_session_index, &ep,
 			       session_listener->user_cb_data);
 
-  /*TODO - Unregister check in close for this listener */
+  if (vcm->session_io_thread.io_sessions_lockp)
+    {
+      /* Throw this new accepted session index into the rx poll thread pool */
+      clib_spinlock_lock (&vcm->session_io_thread.io_sessions_lockp);
+      u32 *active_session_index;
+      pool_get (vcm->session_io_thread.active_session_indexes,
+		active_session_index);
+      *active_session_index = ecr->accepted_session_index;
+      clib_spinlock_unlock (&vcm->session_io_thread.io_sessions_lockp);
+    }
 
+  /*TODO - Unregister check in close for this listener */
   return;
 
 done:
@@ -541,7 +677,7 @@ vce_poll_wait_connect_request_handler_fn (void *arg)
   vce_event_t *ev;
   /* Retrieve the VCL_EVENT_CONNECT_REQ_ACCEPTED event */
   ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
-  vce_event_connect_request_t *ecr = (vce_event_connect_request_t *) ev->data;
+  vce_event_connect_request_t *ecr = vce_get_event_data (ev, sizeof (*ecr));
 
   /* Add the accepted_session_index to the FIFO */
   clib_spinlock_lock (&vcm->session_fifo_lockp);
@@ -551,7 +687,7 @@ vce_poll_wait_connect_request_handler_fn (void *arg)
 
   /* Recycling the event. */
   clib_spinlock_lock (&(vcm->event_thread.events_lockp));
-  vcm->event_thread.recycle_event = 1;
+  ev->recycle = 1;
   clib_fifo_add1 (vcm->event_thread.event_index_fifo, reg->ev_idx);
   clib_spinlock_unlock (&(vcm->event_thread.events_lockp));
 }
@@ -811,8 +947,8 @@ vppcom_app_send_attach (void)
     (vcm->cfg.app_scope_global ? APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE : 0) |
     (app_is_proxy ? APP_OPTIONS_FLAGS_IS_PROXY : 0);
   bmp->options[APP_OPTIONS_PROXY_TRANSPORT] =
-    (vcm->cfg.app_proxy_transport_tcp ? 1 << TRANSPORT_PROTO_TCP : 0) |
-    (vcm->cfg.app_proxy_transport_udp ? 1 << TRANSPORT_PROTO_UDP : 0);
+    (u64) ((vcm->cfg.app_proxy_transport_tcp ? 1 << TRANSPORT_PROTO_TCP : 0) |
+	   (vcm->cfg.app_proxy_transport_udp ? 1 << TRANSPORT_PROTO_UDP : 0));
   bmp->options[APP_OPTIONS_SEGMENT_SIZE] = vcm->cfg.segment_size;
   bmp->options[APP_OPTIONS_ADD_SEGMENT_SIZE] = vcm->cfg.add_segment_size;
   bmp->options[APP_OPTIONS_RX_FIFO_SIZE] = vcm->cfg.rx_fifo_size;
@@ -1085,6 +1221,16 @@ done:
   /*
    * Setup session
    */
+  if (vcm->session_io_thread.io_sessions_lockp)
+    {
+      // Add this connection to the active io sessions list
+      clib_spinlock_lock (&vcm->session_io_thread.io_sessions_lockp);
+      u32 *active_session_index;
+      pool_get (vcm->session_io_thread.active_session_indexes,
+		active_session_index);
+      *active_session_index = session_index;
+      clib_spinlock_unlock (&vcm->session_io_thread.io_sessions_lockp);
+    }
   session->vpp_event_queue = uword_to_pointer (mp->vpp_event_queue_address,
 					       svm_queue_t *);
 
@@ -1360,7 +1506,7 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   /* Allocate local session and set it up */
   pool_get (vcm->sessions, session);
   memset (session, 0, sizeof (*session));
-  session_index = session - vcm->sessions;
+  session_index = (u32) (session - vcm->sessions);
 
   rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
   rx_fifo->client_session_index = session_index;
@@ -1388,10 +1534,8 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   clib_spinlock_lock (&vcm->event_thread.events_lockp);
 
   pool_get (vcm->event_thread.vce_events, ev);
-  ev->data = clib_mem_alloc (sizeof (vce_event_connect_request_t));
-  ev->refcnt = 0;
   ev_idx = (u32) (ev - vcm->event_thread.vce_events);
-  ecr = ev->data;
+  ecr = vce_get_event_data (ev, sizeof (*ecr));
   ev->evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
   listen_session = vppcom_session_table_lookup_listener (mp->listener_handle);
   ev->evk.session_index = (u32) (listen_session - vcm->sessions);
@@ -1400,7 +1544,6 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   clib_spinlock_unlock (&vcm->event_thread.events_lockp);
 
   rv = vce_generate_event (&vcm->event_thread, ev_idx);
-
   ASSERT (rv == 0);
 
   if (VPPCOM_DEBUG > 1)
@@ -1454,6 +1597,9 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
 
 }
 
+/* VPP combines bind and listen as one operation. VCL manages the separation
+ * of bind and listen locally via vppcom_session_bind() and
+ * vppcom_session_listen() */
 static void
 vppcom_send_bind_sock (session_t * session, u32 session_index)
 {
@@ -2194,6 +2340,7 @@ vppcom_app_create (char *app_name)
 			  vcm->cfg.listen_queue_size);
       vppcom_cfg_read (conf_fname);
 
+
       env_var_str = getenv (VPPCOM_ENV_API_PREFIX);
       if (env_var_str)
 	{
@@ -2310,7 +2457,6 @@ vppcom_app_create (char *app_name)
 
       rv = vce_start_event_thread (&(vcm->event_thread), 20);
 
-
       if (VPPCOM_DEBUG > 0)
 	clib_warning ("VCL<%d>: sending session enable", getpid ());
 
@@ -2704,7 +2850,7 @@ vppcom_session_listen (uint32_t listen_session_index, uint32_t q_len)
 
   if (VPPCOM_DEBUG > 0)
     clib_warning ("VCL<%d>: vpp handle 0x%llx, "
-		  "sid %u: sending bind request...",
+		  "sid %u: sending VPP bind+listen request...",
 		  getpid (), listen_vpp_handle, listen_session_index);
 
   vppcom_send_bind_sock (listen_session, listen_session_index);
@@ -2717,10 +2863,10 @@ vppcom_session_listen (uint32_t listen_session_index, uint32_t q_len)
   if (PREDICT_FALSE (retval))
     {
       if (VPPCOM_DEBUG > 0)
-	clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: bind failed! "
-		      "returning %d (%s)", getpid (),
-		      listen_session->vpp_handle, listen_session_index,
-		      retval, vppcom_retval_str (retval));
+	clib_warning
+	  ("VCL<%d>: vpp handle 0x%llx, sid %u: bind+listen failed! "
+	   "returning %d (%s)", getpid (), listen_session->vpp_handle,
+	   listen_session_index, retval, vppcom_retval_str (retval));
       clib_spinlock_unlock (&vcm->sessions_lockp);
       rv = retval;
       goto done;
@@ -2746,15 +2892,21 @@ vppcom_session_register_listener (uint32_t session_index,
   vce_event_key_t evk;
   vppcom_session_listener_t *listener_args;
 
+  if (!vcm->session_io_thread.io_sessions_lockp)
+    rv = vppcom_start_io_event_thread (&vcm->session_io_thread, 100	/* DAW_TODO: ??? hard-coded value */
+      );
+  if (rv)
+    {
+      goto done;
+    }
   rv = vppcom_session_listen (session_index, q_len);
   if (rv)
     {
       goto done;
     }
 
-
   /* Register handler for connect_request event on listen_session_index */
-  listener_args = clib_mem_alloc (sizeof (vppcom_session_listener_t));
+  listener_args = clib_mem_alloc (sizeof (vppcom_session_listener_t));	// DAW_TODO: Use a pool instead of thrashing the memory allocator!
   listener_args->user_cb = cb;
   listener_args->user_cb_data = ptr;
   listener_args->user_errcb = errcb;
@@ -2841,23 +2993,25 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
   evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
   reg = vce_register_handler (&vcm->event_thread, &evk,
 			      vce_connect_request_handler_fn, 0);
+  clib_spinlock_lock (&(vcm->event_thread.events_lockp));
   ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
   pthread_mutex_lock (&reg->handler_lock);
   while (!ev)
     {
-      rv =
-	pthread_cond_timedwait (&reg->handler_cond, &reg->handler_lock, &ts);
+      clib_spinlock_unlock (&(vcm->event_thread.events_lockp));
+      rv = pthread_cond_timedwait (&reg->handler_cond,
+				   &reg->handler_lock, &ts);
       if (rv == ETIMEDOUT)
 	{
 	  rv = VPPCOM_EAGAIN;
 	  goto cleanup;
 	}
+      clib_spinlock_lock (&(vcm->event_thread.events_lockp));
       ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
     }
-  result = (vce_event_connect_request_t *) ev->data;
+  result = vce_get_event_data (ev, sizeof (*result));
   client_session_index = result->accepted_session_index;
-
-
+  clib_spinlock_unlock (&(vcm->event_thread.events_lockp));
 
   /* Remove from the FIFO used to service epoll */
   clib_spinlock_lock (&vcm->session_fifo_lockp);
@@ -2982,8 +3136,17 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
   rv = (int) client_session_index;
-  vce_clear_event (&vcm->event_thread, ev);
-
+  vce_clear_event (&vcm->event_thread, reg->ev_idx);
+  if (vcm->session_io_thread.io_sessions_lockp)
+    {
+      /* Throw this new accepted session index into the rx poll thread pool */
+      clib_spinlock_lock (&vcm->session_io_thread.io_sessions_lockp);
+      u32 *active_session_index;
+      pool_get (vcm->session_io_thread.active_session_indexes,
+		active_session_index);
+      *active_session_index = client_session_index;
+      clib_spinlock_unlock (&vcm->session_io_thread.io_sessions_lockp);
+    }
 cleanup:
   vce_unregister_handler (&vcm->event_thread, reg);
   pthread_mutex_unlock (&reg->handler_lock);
@@ -3285,6 +3448,41 @@ done:
 }
 
 int
+vppcom_session_register_ioevent_cb (uint32_t session_index,
+				    vppcom_session_ioevent_cb cb,
+				    uint8_t rx, void *ptr)
+{
+  int rv = VPPCOM_OK;
+  vce_event_key_t evk;
+  vppcom_session_ioevent_t *ioevent;
+
+  if (!vcm->session_io_thread.io_sessions_lockp)
+    rv = vppcom_start_io_event_thread (&vcm->session_io_thread, 100	/* DAW_TODO: ??? hard-coded value */
+      );
+
+  if (rv == VPPCOM_OK)
+    {
+      void *io_evt_ndx;
+
+      /* Register handler for ioevent on session_index */
+      clib_spinlock_lock (&vcm->session_io_thread.io_sessions_lockp);
+      pool_get (vcm->session_io_thread.ioevents, ioevent);
+      io_evt_ndx = (void *) (ioevent - vcm->session_io_thread.ioevents);
+      ioevent->user_cb = cb;
+      ioevent->user_cb_data = ptr;
+      clib_spinlock_unlock (&vcm->session_io_thread.io_sessions_lockp);
+
+      evk.session_index = session_index;
+      evk.eid = rx ? VCL_EVENT_IOEVENT_RX_FIFO : VCL_EVENT_IOEVENT_TX_FIFO;
+
+      (void) vce_register_handler (&vcm->event_thread, &evk,
+				   vce_registered_ioevent_handler_fn,
+				   io_evt_ndx);
+    }
+  return rv;
+}
+
+int
 vppcom_session_write (uint32_t session_index, void *buf, size_t n)
 {
   session_t *session = 0;
@@ -3339,7 +3537,12 @@ vppcom_session_write (uint32_t session_index, void *buf, size_t n)
     }
   while (!is_nonblocking && (n_write <= 0));
 
-  /* If event wasn't set, add one */
+  /* If event wasn't set, add one
+   *
+   * To reduce context switching, can check if an
+   * event is already there for this event_key, but for now
+   * this will suffice. */
+
   if ((n_write > 0) && svm_fifo_set_event (tx_fifo))
     {
       /* Fabricate TX event, send to vpp */
diff --git a/src/vcl/vppcom.h b/src/vcl/vppcom.h
index 34a69b2c2ec..c752e50413b 100644
--- a/src/vcl/vppcom.h
+++ b/src/vcl/vppcom.h
@@ -144,6 +144,13 @@ typedef struct _vcl_poll
   short *revents;
 } vcl_poll_t;
 
+typedef struct vppcom_ioevent_
+{
+  uint32_t session_index;
+  size_t bytes;
+} vppcom_ioevent_t;
+
+
 /*
  * VPPCOM Public API Functions
  */
@@ -221,6 +228,34 @@ typedef void (*vppcom_session_listener_cb) (uint32_t, vppcom_endpt_t *,
 					    void *);
 
 /**
+ * User registered callback for IO events (rx/tx)
+ * @param vppcom_ioevent_t* -
+ * @param void* - user passed arg to pass back
+ */
+typedef void (*vppcom_session_ioevent_cb) (vppcom_ioevent_t *, void *);
+
+/**
+ * @brief vppcom_session_register_listener accepts a bound session_index, and
+ * listens for connections.
+ *
+ * On successful connection, calls registered callback (cb) with new
+ * session_index.
+ *
+ * On error, calls registered error callback (errcb).
+ *
+ * @param session_index - bound session_index to create listener on
+ * @param cb  - on new accepted session callback
+ * @param errcb  - on failure callback
+ * @param flags - placeholder for future use. Must be ZERO
+ * @param q_len - max listener connection backlog
+ * @param ptr - user data
+ * @return
+ */
+extern int vppcom_session_register_ioevent_cb (uint32_t session_index,
+					       vppcom_session_ioevent_cb cb,
+					       uint8_t rx, void *ptr);
+
+/**
  * User registered ERROR callback for any errors associated with
  * handling vppcom_session_register_listener() and connections
  * @param void* - user passed arg to pass back