Session layer improvements

Among others:
- Moved app event queue to shared memory segment
- Use private memory segment for builtin apps
- Remove pid from svm fifo
- Protect session fifo (de)allocation
- Use fifo event for session disconnects
- Have session queue node poll in all wk threads

Change-Id: I89dbf7fdfebef12f5ef2b34ba3ef3c2c07f49ff2
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/udp/udp_input.c b/src/vnet/udp/udp_input.c
index 810278e..e6b4f8f 100644
--- a/src/vnet/udp/udp_input.c
+++ b/src/vnet/udp/udp_input.c
@@ -145,8 +145,7 @@
 		  goto trace0;
 		}
 
-	      svm_fifo_enqueue_nowait (f0, 0 /* pid */ ,
-				       udp_len0 - sizeof (*udp0),
+	      svm_fifo_enqueue_nowait (f0, udp_len0 - sizeof (*udp0),
 				       (u8 *) (udp0 + 1));
 
 	      b0->error = node->errors[SESSION_ERROR_ENQUEUED];
@@ -255,7 +254,7 @@
 	{
 	  /* Fabricate event */
 	  evt.fifo = s0->server_rx_fifo;
-	  evt.event_type = FIFO_EVENT_SERVER_RX;
+	  evt.event_type = FIFO_EVENT_APP_RX;
 	  evt.event_id = serial_number++;
 
 	  /* Add event to server's event queue */