session: async rx event notifications

Move from synchronous flushing of io and ctrl events from transports to
applications to an async model via a new session_input input node that
runs in interrupt mode. Events are coalesced per application worker.

On the one hand, this helps by minimizing message queue locking churn.
And on the other, it opens the possibility for further optimizations of
event message generation, obviates need for rx rescheduling rpcs and is
a first step towards a fully async data/io rx path.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Id6bebcb65fc9feef8aa02ddf1af6d9ba6f6745ce

1 files changed, 5 insertions, 4 deletions

diff --git a/src/plugins/http/http.c b/src/plugins/http/http.c
index d25123a757d..503752c377e 100644
--- a/src/plugins/http/http.c
+++ b/src/plugins/http/http.c
@@ -503,7 +503,7 @@ state_srv_wait_method (http_conn_t *hc, transport_send_params_t *sp)
   hc->http_state = HTTP_STATE_WAIT_APP;
 
   app_wrk = app_worker_get_if_valid (as->app_wrk_index);
-  app_worker_lock_and_send_event (app_wrk, as, SESSION_IO_EVT_RX);
+  app_worker_rx_notify (app_wrk, as);
 
   return HTTP_SM_STOP;
 
@@ -777,7 +777,7 @@ state_cln_wait_method (http_conn_t *hc, transport_send_params_t *sp)
     }
 
   app_wrk = app_worker_get_if_valid (as->app_wrk_index);
-  app_worker_lock_and_send_event (app_wrk, as, SESSION_IO_EVT_RX);
+  app_worker_rx_notify (app_wrk, as);
   return HTTP_SM_STOP;
 }
 
@@ -808,7 +808,7 @@ cln_drain_rx_buf (http_conn_t *hc, session_t *ts, session_t *as)
   app_wrk = app_worker_get_if_valid (as->app_wrk_index);
   ASSERT (app_wrk);
 
-  app_worker_lock_and_send_event (app_wrk, as, SESSION_IO_EVT_RX);
+  app_worker_rx_notify (app_wrk, as);
   return 1;
 }
 
@@ -864,8 +864,9 @@ maybe_reschedule:
   if (hc->rx_buf_offset < vec_len (hc->rx_buf) ||
       svm_fifo_max_dequeue_cons (ts->rx_fifo))
     {
+      /* TODO is the flag really needed? */
       if (svm_fifo_set_event (ts->rx_fifo))
-	session_send_io_evt_to_thread (ts->rx_fifo, SESSION_IO_EVT_BUILTIN_RX);
+	session_enqueue_notify (ts);
     }
   return HTTP_SM_CONTINUE;
 }