[HICN-342] No need to take a lock on the hash entry if the lookup for

a data hit the CS. Data packets coming from the network are dropped,
data packets coming from an application face are either dropped or
sent to the push node (which does not require a lock on the hash
entry)

Change-Id: Icf662dffa33b9dda2e2a69fc2104a69a82ef19fd
Signed-off-by: Alberto Compagno <acompagn+fdio@cisco.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/hicn-plugin/src/pcs.h b/hicn-plugin/src/pcs.h
index c7e8a4b59..d9c48954e 100644
--- a/hicn-plugin/src/pcs.h
+++ b/hicn-plugin/src/pcs.h
@@ -499,8 +499,16 @@ hicn_pcs_cs_update (vlib_main_t * vm, hicn_pit_cs_t * pitcs,
           policy_vft->hicn_cs_delete_get (pitcs, policy_state,
                                           &node, &pcs_entry, &hash_entry);
 
-          hicn_pcs_cs_delete (vm, pitcs, &pcs_entry, &node, hash_entry, NULL,
-                              NULL);
+          /*
+           * We don't have to decrease the lock (therefore we cannot
+           * use hicn_pcs_cs_delete function)
+           */
+          policy_vft->hicn_cs_dequeue (pitcs, node, pcs_entry, policy_state);
+
+          hicn_cs_delete_trimmed (pitcs, &pcs_entry, hash_entry, &node, vm);
+
+          /* Update the global CS counter */
+          pitcs->pcs_cs_count--;
         }
     }
   else
@@ -541,14 +549,14 @@ hicn_pcs_cs_delete (vlib_main_t * vm, hicn_pit_cs_t * pitcs,
     }
 
   /* A data could have been inserted in the CS through a push. In this case locks == 0 */
-  if (hash_entry->locks == 0 || hash_entry->locks == 1)
+  hash_entry->locks--;
+  if (hash_entry->locks == 0)
     {
       hicn_pcs_delete_internal
 	(pitcs, pcs_entryp, hash_entry, nodep, vm, dpo_vft, hicn_dpo_id);
     }
   else
     {
-      hash_entry->locks--;
       hash_entry->he_flags |= HICN_HASH_ENTRY_FLAG_DELETED;
     }
 }
@@ -603,8 +611,16 @@ hicn_pcs_cs_insert (vlib_main_t * vm, hicn_pit_cs_t * pitcs,
 	  policy_vft->hicn_cs_delete_get (pitcs, policy_state,
 					  &node, &pcs_entry, &hash_entry);
 
-	  hicn_pcs_cs_delete (vm, pitcs, &pcs_entry, &node, hash_entry, NULL,
-			      NULL);
+          /*
+           * We don't have to decrease the lock (therefore we cannot
+           * use hicn_pcs_cs_delete function)
+           */
+          policy_vft->hicn_cs_dequeue (pitcs, node, pcs_entry, policy_state);
+
+          hicn_cs_delete_trimmed (pitcs, &pcs_entry, hash_entry, &node, vm);
+
+          /* Update the global CS counter */
+          pitcs->pcs_cs_count--;
 	}
     }
   return ret;