VCL IOEvent external API callback
[vpp.git] / src / vcl / vppcom.c
index bb24869..a66926d 100644 (file)
@@ -161,6 +161,7 @@ typedef struct
   u64 client_queue_address;
   u64 options[16];
   elog_track_t elog_track;
+  vce_event_handler_reg_t *poll_reg;
 } session_t;
 
 typedef struct vppcom_cfg_t_
@@ -192,30 +193,57 @@ typedef struct vppcom_cfg_t_
 /* VPPCOM Event typedefs */
 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_
 {
-  u8 size;
-  u8 handled;
   u32 accepted_session_index;
 } vce_event_connect_request_t;
 
+typedef struct vppcom_session_listener
+{
+  vppcom_session_listener_cb user_cb;
+  vppcom_session_listener_errcb user_errcb;
+  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;
   u32 debug;
-  u32 *client_session_index_fifo;
   int main_cpu;
 
+  /* FIFO for accepted connections - used in epoll/select */
+  clib_spinlock_t session_fifo_lockp;
+  u32 *client_session_index_fifo;
+
   /* vpp input queue */
   svm_queue_t *vl_input_queue;
 
   /* API client handle */
   u32 my_client_index;
-
   /* Session pool */
   clib_spinlock_t sessions_lockp;
   session_t *sessions;
@@ -245,6 +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;
@@ -355,6 +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)
 {
@@ -370,6 +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)
 {
@@ -434,10 +543,105 @@ write_elog (void)
 
 }
 
+static inline void
+vppcom_send_accept_session_reply (u64 handle, u32 context, int retval)
+{
+  vl_api_accept_session_reply_t *rmp;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  memset (rmp, 0, sizeof (*rmp));
+  rmp->_vl_msg_id = ntohs (VL_API_ACCEPT_SESSION_REPLY);
+  rmp->retval = htonl (retval);
+  rmp->context = context;
+  rmp->handle = handle;
+  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
+}
+
 /*
  * VPPCOM Event Functions
  */
 
+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;
+  vce_event_connect_request_t *ecr;
+  vce_event_t *ev;
+  vppcom_endpt_t ep;
+
+  session_t *new_session;
+  int rv;
+
+  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_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)
+    clib_memcpy (&ep.ip, &new_session->peer_addr.ip46.ip4,
+                sizeof (ip4_address_t));
+  else
+    clib_memcpy (&ep.ip, &new_session->peer_addr.ip46.ip6,
+                sizeof (ip6_address_t));
+
+  vppcom_send_accept_session_reply (new_session->vpp_handle,
+                                   new_session->client_context,
+                                   0 /* retval OK */ );
+  clib_spinlock_unlock (&vcm->sessions_lockp);
+
+  (session_listener->user_cb) (ecr->accepted_session_index, &ep,
+                              session_listener->user_cb_data);
+
+  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:
+  ASSERT (0);                  // If we can't get a lock or accepted session fails, lets blow up.
+}
+
 /**
  *  * @brief vce_connect_request_handler_fn
  * - used for listener sessions
@@ -452,21 +656,13 @@ vce_connect_request_handler_fn (void *arg)
 {
   vce_event_handler_reg_t *reg = (vce_event_handler_reg_t *) arg;
 
-  vce_event_connect_request_t *ecr;
-  vce_event_t *ev;
-
-  ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
-
-  ecr = (vce_event_connect_request_t *) ev->data;
-
   pthread_mutex_lock (&reg->handler_lock);
-  ecr->handled = 1;
   pthread_cond_signal (&reg->handler_cond);
   pthread_mutex_unlock (&reg->handler_lock);
 }
 
 /**
- * @brief vce_epoll_wait_connect_request_handler_fn
+ * @brief vce_poll_wait_connect_request_handler_fn
  * - used by vppcom_epoll_xxxx() for listener sessions
  * - when a vl_api_accept_session_t_handler() generates an event
  *   this callback is alerted and sets the fields that vppcom_epoll_wait()
@@ -475,23 +671,23 @@ vce_connect_request_handler_fn (void *arg)
  * @param arg - void* to be cast to vce_event_handler_reg_t*
  */
 void
-vce_epoll_wait_connect_request_handler_fn (void *arg)
+vce_poll_wait_connect_request_handler_fn (void *arg)
 {
   vce_event_handler_reg_t *reg = (vce_event_handler_reg_t *) 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->sessions_lockp);
+  clib_spinlock_lock (&vcm->session_fifo_lockp);
   clib_fifo_add1 (vcm->client_session_index_fifo,
                  ecr->accepted_session_index);
-  clib_spinlock_unlock (&vcm->sessions_lockp);
+  clib_spinlock_unlock (&vcm->session_fifo_lockp);
 
   /* 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));
 }
@@ -751,8 +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;
@@ -1025,6 +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 *);
 
@@ -1147,8 +1353,7 @@ done:
 
   session->vpp_handle = mp->handle;
   session->lcl_addr.is_ip4 = mp->lcl_is_ip4;
-  clib_memcpy (&session->lcl_addr.ip46, mp->lcl_ip,
-              sizeof (session->peer_addr.ip46));
+  session->lcl_addr.ip46 = to_ip46 (!mp->lcl_is_ip4, mp->lcl_ip);
   session->lcl_port = mp->lcl_port;
   vppcom_session_table_add_listener (mp->handle, session_index);
   session->state = STATE_LISTEN;
@@ -1256,20 +1461,6 @@ format_ip46_address (u8 * s, va_list * args)
     format (s, "%U", format_ip6_address, &ip46->ip6);
 }
 
-static inline void
-vppcom_send_accept_session_reply (u64 handle, u32 context, int retval)
-{
-  vl_api_accept_session_reply_t *rmp;
-
-  rmp = vl_msg_api_alloc (sizeof (*rmp));
-  memset (rmp, 0, sizeof (*rmp));
-  rmp->_vl_msg_id = ntohs (VL_API_ACCEPT_SESSION_REPLY);
-  rmp->retval = htonl (retval);
-  rmp->context = context;
-  rmp->handle = handle;
-  vl_msg_api_send_shmem (vcm->vl_input_queue, (u8 *) & rmp);
-}
-
 static void
 vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
 {
@@ -1280,10 +1471,15 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   vce_event_t *ev;
   int rv;
   u32 ev_idx;
-
+  uword elts = 0;
 
   clib_spinlock_lock (&vcm->sessions_lockp);
-  if (!clib_fifo_free_elts (vcm->client_session_index_fifo))
+
+  clib_spinlock_lock (&vcm->session_fifo_lockp);
+  elts = clib_fifo_free_elts (vcm->client_session_index_fifo);
+  clib_spinlock_unlock (&vcm->session_fifo_lockp);
+
+  if (!elts)
     {
       clib_warning ("VCL<%d>: client session queue is full!", getpid ());
       vppcom_send_accept_session_reply (mp->handle, mp->context,
@@ -1310,7 +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;
@@ -1326,8 +1522,7 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
   session->state = STATE_ACCEPT;
   session->peer_port = mp->port;
   session->peer_addr.is_ip4 = mp->is_ip4;
-  clib_memcpy (&session->peer_addr.ip46, mp->ip,
-              sizeof (session->peer_addr.ip46));
+  session->peer_addr.ip46 = to_ip46 (!mp->is_ip4, mp->ip);
 
   /* Add it to lookup table */
   hash_set (vcm->session_index_by_vpp_handles, mp->handle, session_index);
@@ -1339,27 +1534,24 @@ 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);
-  ecr->handled = 0;
   ecr->accepted_session_index = session_index;
 
   clib_spinlock_unlock (&vcm->event_thread.events_lockp);
 
   rv = vce_generate_event (&vcm->event_thread, ev_idx);
-
   ASSERT (rv == 0);
 
   if (VPPCOM_DEBUG > 1)
     clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: client accept "
                  "request from %s address %U port %d queue %p!", getpid (),
                  mp->handle, session_index, mp->is_ip4 ? "IPv4" : "IPv6",
-                 format_ip46_address, &mp->ip, mp->is_ip4,
+                 format_ip46_address, &mp->ip,
+                 mp->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
                  clib_net_to_host_u16 (mp->port), session->vpp_event_queue);
 
   if (VPPCOM_DEBUG > 0)
@@ -1400,10 +1592,14 @@ vl_api_accept_session_t_handler (vl_api_accept_session_t * mp)
          clib_warning ("ip6");
        }
     }
+
   clib_spinlock_unlock (&vcm->sessions_lockp);
 
 }
 
+/* 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)
 {
@@ -2139,10 +2335,12 @@ vppcom_app_create (char *app_name)
        conf_fname = VPPCOM_CONF_DEFAULT;
       vppcom_cfg_heapsize (conf_fname);
       vcl_cfg = &vcm->cfg;
+      clib_spinlock_init (&vcm->session_fifo_lockp);
       clib_fifo_validate (vcm->client_session_index_fifo,
                          vcm->cfg.listen_queue_size);
       vppcom_cfg_read (conf_fname);
 
+
       env_var_str = getenv (VPPCOM_ENV_API_PREFIX);
       if (env_var_str)
        {
@@ -2157,25 +2355,6 @@ vppcom_app_create (char *app_name)
                          "filename (%s) from " VPPCOM_ENV_API_PREFIX "!",
                          getpid (), env_var_str, vcl_cfg->vpp_api_filename);
        }
-
-      env_var_str = getenv (VPPCOM_ENV_APP_NAMESPACE_SECRET);
-      if (env_var_str)
-       {
-         u64 tmp;
-         if (sscanf (env_var_str, "%lu", &tmp) != 1)
-           clib_warning ("VCL<%d>: WARNING: Invalid namespace secret "
-                         "specified in the environment variable "
-                         VPPCOM_ENV_APP_NAMESPACE_SECRET
-                         " (%s)!\n", getpid (), env_var_str);
-         else
-           {
-             vcm->cfg.namespace_secret = tmp;
-             if (VPPCOM_DEBUG > 0)
-               clib_warning ("VCL<%d>: configured namespace secret "
-                             "(%lu) from " VPPCOM_ENV_APP_NAMESPACE_ID "!",
-                             getpid (), vcm->cfg.namespace_secret);
-           }
-       }
       env_var_str = getenv (VPPCOM_ENV_APP_NAMESPACE_ID);
       if (env_var_str)
        {
@@ -2205,7 +2384,7 @@ vppcom_app_create (char *app_name)
              if (VPPCOM_DEBUG > 0)
                clib_warning ("VCL<%d>: configured namespace secret "
                              "(%lu) from "
-                             VPPCOM_ENV_APP_NAMESPACE_ID
+                             VPPCOM_ENV_APP_NAMESPACE_SECRET
                              "!", getpid (), vcm->cfg.namespace_secret);
            }
        }
@@ -2278,7 +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 ());
 
@@ -2314,6 +2492,7 @@ void
 vppcom_app_destroy (void)
 {
   int rv;
+  f64 orig_app_timeout;
 
   if (vcm->my_client_index == ~0)
     return;
@@ -2341,7 +2520,10 @@ vppcom_app_destroy (void)
     }
 
   vppcom_app_detach ();
+  orig_app_timeout = vcm->cfg.app_timeout;
+  vcm->cfg.app_timeout = 2.0;
   rv = vppcom_wait_for_app_state_change (STATE_APP_ENABLED);
+  vcm->cfg.app_timeout = orig_app_timeout;
   if (PREDICT_FALSE (rv))
     {
       if (VPPCOM_DEBUG > 0)
@@ -2594,7 +2776,7 @@ vppcom_session_bind (uint32_t session_index, vppcom_endpt_t * ep)
                  "port %u, proto %s", getpid (), session_index,
                  session->lcl_addr.is_ip4 ? "IPv4" : "IPv6",
                  format_ip46_address, &session->lcl_addr.ip46,
-                 session->lcl_addr.is_ip4,
+                 session->lcl_addr.is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
                  clib_net_to_host_u16 (session->lcl_port),
                  session->proto ? "UDP" : "TCP");
 
@@ -2668,7 +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);
@@ -2681,17 +2863,60 @@ 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;
     }
 
+  clib_spinlock_lock (&vcm->session_fifo_lockp);
   clib_fifo_validate (vcm->client_session_index_fifo, q_len);
+  clib_spinlock_unlock (&vcm->session_fifo_lockp);
+
   clib_spinlock_unlock (&vcm->sessions_lockp);
+
+done:
+  return rv;
+}
+
+int
+vppcom_session_register_listener (uint32_t session_index,
+                                 vppcom_session_listener_cb cb,
+                                 vppcom_session_listener_errcb
+                                 errcb, uint8_t flags, int q_len, void *ptr)
+{
+  int rv = VPPCOM_OK;
+  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)); // 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;
+
+  evk.session_index = session_index;
+  evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
+  (void) vce_register_handler (&vcm->event_thread, &evk,
+                              vce_registered_listener_connect_handler_fn,
+                              listener_args);
+
 done:
   return rv;
 }
@@ -2767,37 +2992,42 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
   evk.session_index = listen_session_index;
   evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
   reg = vce_register_handler (&vcm->event_thread, &evk,
-                             vce_connect_request_handler_fn);
+                             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);
-
-  result = (vce_event_connect_request_t *) ev->data;
   pthread_mutex_lock (&reg->handler_lock);
-  while (!result->handled)
+  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_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->sessions_lockp);
+  clib_spinlock_lock (&vcm->session_fifo_lockp);
   if (clib_fifo_elts (vcm->client_session_index_fifo))
     {
       u32 tmp_client_session_index;
       clib_fifo_sub1 (vcm->client_session_index_fifo,
                      tmp_client_session_index);
+      /* It wasn't ours... put it back ... */
       if (tmp_client_session_index != client_session_index)
        clib_fifo_add1 (vcm->client_session_index_fifo,
                        tmp_client_session_index);
     }
-  clib_spinlock_unlock (&vcm->sessions_lockp);
+  clib_spinlock_unlock (&vcm->session_fifo_lockp);
+
+  clib_spinlock_lock (&vcm->sessions_lockp);
 
   rv = vppcom_session_at_index (client_session_index, &client_session);
   if (PREDICT_FALSE (rv))
@@ -2807,7 +3037,7 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
                    "lookup failed! returning %d (%s)", getpid (),
                    listen_vpp_handle, listen_session_index,
                    client_session_index, rv, vppcom_retval_str (rv));
-      goto done;
+      goto cleanup;
     }
 
   if (flags & O_NONBLOCK)
@@ -2847,7 +3077,8 @@ vppcom_session_accept (uint32_t listen_session_index, vppcom_endpt_t * ep,
                  client_session_index,
                  client_session->lcl_addr.is_ip4 ? "IPv4" : "IPv6",
                  format_ip46_address, &client_session->lcl_addr.ip46,
-                 client_session->lcl_addr.is_ip4,
+                 client_session->lcl_addr.is_ip4 ?
+                 IP46_TYPE_IP4 : IP46_TYPE_IP6,
                  clib_net_to_host_u16 (client_session->lcl_port));
 
   if (VPPCOM_DEBUG > 0)
@@ -2903,12 +3134,23 @@ 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);
+  rv = (int) client_session_index;
+  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, ev);
+  vce_unregister_handler (&vcm->event_thread, reg);
   pthread_mutex_unlock (&reg->handler_lock);
+
 done:
   return rv;
 }
@@ -2939,7 +3181,8 @@ vppcom_session_connect (uint32_t session_index, vppcom_endpt_t * server_ep)
                      getpid (), session->vpp_handle, session_index,
                      session->peer_addr.is_ip4 ? "IPv4" : "IPv6",
                      format_ip46_address,
-                     &session->peer_addr.ip46, session->peer_addr.is_ip4,
+                     &session->peer_addr.ip46, session->peer_addr.is_ip4 ?
+                     IP46_TYPE_IP4 : IP46_TYPE_IP6,
                      clib_net_to_host_u16 (session->peer_port),
                      session->proto ? "UDP" : "TCP", session->state,
                      vppcom_session_state_str (session->state));
@@ -2958,7 +3201,8 @@ vppcom_session_connect (uint32_t session_index, vppcom_endpt_t * server_ep)
                  getpid (), session->vpp_handle, session_index,
                  session->peer_addr.is_ip4 ? "IPv4" : "IPv6",
                  format_ip46_address,
-                 &session->peer_addr.ip46, session->peer_addr.is_ip4,
+                 &session->peer_addr.ip46, session->peer_addr.is_ip4 ?
+                 IP46_TYPE_IP4 : IP46_TYPE_IP6,
                  clib_net_to_host_u16 (session->peer_port),
                  session->proto ? "UDP" : "TCP");
 
@@ -3136,7 +3380,9 @@ vppcom_session_read_ready (session_t * session, u32 session_index)
 
   if (session->state & STATE_LISTEN)
     {
+      clib_spinlock_lock (&vcm->session_fifo_lockp);
       ready = clib_fifo_elts (vcm->client_session_index_fifo);
+      clib_spinlock_unlock (&vcm->session_fifo_lockp);
     }
   else
     {
@@ -3201,6 +3447,41 @@ done:
   return rv;
 }
 
+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)
 {
@@ -3256,7 +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 */
@@ -3468,8 +3754,31 @@ vppcom_select (unsigned long n_bits, unsigned long *read_map,
                       bits_set = VPPCOM_EBADFD;
                       goto select_done;
                     }
-
-                  rv = vppcom_session_read_ready (session, session_index);
+                  if (session->state & STATE_LISTEN)
+                    {
+                      vce_event_handler_reg_t *reg = 0;
+                      vce_event_key_t evk;
+
+                      /* Check if handler already registered for this
+                       * event.
+                       * If not, register handler for connect_request event
+                       * on listen_session_index
+                       */
+                      evk.session_index = session_index;
+                      evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
+                      reg = vce_get_event_handler (&vcm->event_thread, &evk);
+                      if (!reg)
+                        reg = vce_register_handler (&vcm->event_thread, &evk,
+                                    vce_poll_wait_connect_request_handler_fn,
+                                                   0 /* No callback args */);
+                      rv = vppcom_session_read_ready (session, session_index);
+                      if (rv > 0)
+                        {
+                          vce_unregister_handler (&vcm->event_thread, reg);
+                        }
+                    }
+                  else
+                    rv = vppcom_session_read_ready (session, session_index);
                   clib_spinlock_unlock (&vcm->sessions_lockp);
                   if (except_map && vcm->ex_bitmap &&
                       clib_bitmap_get (vcm->ex_bitmap, session_index) &&
@@ -3649,6 +3958,7 @@ vppcom_epoll_create (void)
   vep_session->vep.prev_sid = ~0;
   vep_session->wait_cont_idx = ~0;
   vep_session->vpp_handle = ~0;
+  vep_session->poll_reg = 0;
 
   if (VPPCOM_DEBUG > 0)
     {
@@ -3694,8 +4004,6 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
 {
   session_t *vep_session;
   session_t *session;
-  vce_event_handler_reg_t *reg = 0;
-  vce_event_t *ev = 0;
   int rv;
 
   if (vep_idx == session_index)
@@ -3779,8 +4087,10 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
          vce_event_key_t evk;
          evk.session_index = session_index;
          evk.eid = VCL_EVENT_CONNECT_REQ_ACCEPTED;
-         reg = vce_register_handler (&vcm->event_thread, &evk,
-                                     vce_epoll_wait_connect_request_handler_fn);
+         vep_session->poll_reg =
+           vce_register_handler (&vcm->event_thread, &evk,
+                                 vce_poll_wait_connect_request_handler_fn,
+                                 0 /* No callback args */ );
        }
       if (VPPCOM_DEBUG > 1)
        clib_warning ("VCL<%d>: EPOLL_CTL_ADD: vep_idx %u, "
@@ -3861,10 +4171,10 @@ vppcom_epoll_ctl (uint32_t vep_idx, int op, uint32_t session_index,
        }
 
       /* VCL Event Un-register handler */
-      if ((session->state & STATE_LISTEN) && reg)
+      if ((session->state & STATE_LISTEN) && vep_session->poll_reg)
        {
-         ev = vce_get_event_from_index (&vcm->event_thread, reg->ev_idx);
-         vce_unregister_handler (&vcm->event_thread, ev);
+         (void) vce_unregister_handler (&vcm->event_thread,
+                                        vep_session->poll_reg);
        }
 
       vep_session->wait_cont_idx =
@@ -4358,7 +4668,8 @@ vppcom_session_attr (uint32_t session_index, uint32_t op,
            clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_PEER_ADDR: sid %u, "
                          "is_ip4 = %u, addr = %U, port %u", getpid (),
                          session_index, ep->is_ip4, format_ip46_address,
-                         &session->peer_addr.ip46, ep->is_ip4,
+                         &session->peer_addr.ip46,
+                         ep->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
                          clib_net_to_host_u16 (ep->port));
          if (VPPCOM_DEBUG > 0)
            {
@@ -4424,7 +4735,8 @@ vppcom_session_attr (uint32_t session_index, uint32_t op,
            clib_warning ("VCL<%d>: VPPCOM_ATTR_GET_LCL_ADDR: sid %u, "
                          "is_ip4 = %u, addr = %U port %d", getpid (),
                          session_index, ep->is_ip4, format_ip46_address,
-                         &session->lcl_addr.ip46, ep->is_ip4,
+                         &session->lcl_addr.ip46,
+                         ep->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
                          clib_net_to_host_u16 (ep->port));
          if (VPPCOM_DEBUG > 0)
            {