diff mbox series

[ovs-dev,v3,1/5] lflow: Factor out the lflow reference handling code into a new module.

Message ID 166912645948.709554.11102663151784344867.stgit@dceara.remote.csb
State Accepted
Headers show
Series Add OVN component templates. | expand

Checks

Context Check Description
ovsrobot/apply-robot warning apply and check: warning
ovsrobot/github-robot-_Build_and_Test success github build: passed
ovsrobot/github-robot-_ovn-kubernetes fail github build: failed

Commit Message

Dumitru Ceara Nov. 22, 2022, 2:14 p.m. UTC
This makes it easier to have an overview of what the code does and at the
same time it allows multiple users to define and manage
"resource <-> object" dependencies.

Acked-by: Han Zhou <hzhou@ovn.org>
Acked-by: Mark Michelson <mmichels@redhat.com>
Signed-off-by: Dumitru Ceara <dceara@redhat.com>
---
V3:
- Added Mark's ack.
V2:
- Addressed Mark's comments:
  - Fixed typos in comments in objdep.h.
  - Made objdep_change_handler return bool (handled successfully or not).
  - Reverted some unrelated style changes.
- Fixed cast style.
- Addressed Han's comments:
  - Removed superfluous 'type' argument name in prototypes.
- Added Han's ack.
---
 controller/lflow.c          |  330 ++++++++++---------------------------------
 controller/lflow.h          |   67 +--------
 controller/ovn-controller.c |   55 +++++--
 lib/automake.mk             |    2 
 lib/objdep.c                |  260 ++++++++++++++++++++++++++++++++++
 lib/objdep.h                |  122 ++++++++++++++++
 6 files changed, 508 insertions(+), 328 deletions(-)
 create mode 100644 lib/objdep.c
 create mode 100644 lib/objdep.h

Comments

0-day Robot Nov. 22, 2022, 2:21 p.m. UTC | #1
Bleep bloop.  Greetings Dumitru Ceara, I am a robot and I have tried out your patch.
Thanks for your contribution.

I encountered some error that I wasn't expecting.  See the details below.


checkpatch:
ERROR: Inappropriate bracing around statement
#1188 FILE: lib/objdep.h:52:
    HMAP_FOR_EACH (NODE, hmap_node, &(MAP)->objs)

Lines checked: 1262, Warnings: 0, Errors: 1


Please check this out.  If you feel there has been an error, please email aconole@redhat.com

Thanks,
0-day Robot
diff mbox series

Patch

diff --git a/controller/lflow.c b/controller/lflow.c
index cc0f31db06..d4434bdee8 100644
--- a/controller/lflow.c
+++ b/controller/lflow.c
@@ -61,7 +61,7 @@  struct lookup_port_aux {
     struct ovsdb_idl_index *sbrec_port_binding_by_name;
     const struct sbrec_datapath_binding *dp;
     const struct sbrec_logical_flow *lflow;
-    struct lflow_resource_ref *lfrr;
+    struct objdep_mgr *deps_mgr;
     const struct hmap *chassis_tunnels;
 };
 
@@ -72,8 +72,8 @@  struct condition_aux {
     const struct sset *active_tunnels;
     const struct sbrec_logical_flow *lflow;
     /* Resource reference to store the port name referenced
-     * in is_chassis_resident() to the logical flow. */
-    struct lflow_resource_ref *lfrr;
+     * in is_chassis_resident() to the object (logical flow). */
+    struct objdep_mgr *deps_mgr;
 };
 
 static struct expr *
@@ -81,7 +81,7 @@  convert_match_to_expr(const struct sbrec_logical_flow *,
                       const struct local_datapath *ldp,
                       struct expr **prereqs, const struct shash *addr_sets,
                       const struct shash *port_groups,
-                      struct lflow_resource_ref *, bool *pg_addr_set_ref);
+                      struct objdep_mgr *, bool *pg_addr_set_ref);
 static void
 add_matches_to_flow_table(const struct sbrec_logical_flow *,
                           const struct local_datapath *,
@@ -94,17 +94,6 @@  consider_logical_flow(const struct sbrec_logical_flow *lflow,
                       bool is_recompute,
                       struct lflow_ctx_in *l_ctx_in,
                       struct lflow_ctx_out *l_ctx_out);
-static void lflow_resource_add(struct lflow_resource_ref *, enum ref_type,
-                               const char *ref_name, const struct uuid *,
-                               size_t ref_count);
-static struct ref_lflow_node *ref_lflow_lookup(struct hmap *ref_lflow_table,
-                                               enum ref_type,
-                                               const char *ref_name);
-static struct lflow_ref_node *lflow_ref_lookup(struct hmap *lflow_ref_table,
-                                               const struct uuid *lflow_uuid);
-static void ref_lflow_node_destroy(struct ref_lflow_node *);
-static void lflow_resource_destroy_lflow(struct lflow_resource_ref *,
-                                         const struct uuid *lflow_uuid);
 
 static void add_port_sec_flows(const struct shash *binding_lports,
                                const struct sbrec_chassis *,
@@ -125,8 +114,8 @@  lookup_port_cb(const void *aux_, const char *port_name, unsigned int *portp)
     /* Store the name that used to lookup the lport to lflow reference, so that
      * in the future when the lport's port binding changes, the logical flow
      * that references this lport can be reprocessed. */
-    lflow_resource_add(aux->lfrr, REF_TYPE_PORTBINDING, port_name,
-                       &aux->lflow->header_.uuid, 0);
+    objdep_mgr_add(aux->deps_mgr, OBJDEP_TYPE_PORTBINDING, port_name,
+                   &aux->lflow->header_.uuid);
 
     const struct sbrec_port_binding *pb
         = lport_lookup_by_name(aux->sbrec_port_binding_by_name, port_name);
@@ -141,8 +130,8 @@  lookup_port_cb(const void *aux_, const char *port_name, unsigned int *portp)
      * this multicast group can be reprocessed. */
     struct ds mg_key = DS_EMPTY_INITIALIZER;
     get_mc_group_key(port_name, aux->dp->tunnel_key, &mg_key);
-    lflow_resource_add(aux->lfrr, REF_TYPE_MC_GROUP, ds_cstr(&mg_key),
-                       &aux->lflow->header_.uuid, 0);
+    objdep_mgr_add(aux->deps_mgr, OBJDEP_TYPE_MC_GROUP, ds_cstr(&mg_key),
+                   &aux->lflow->header_.uuid);
     ds_destroy(&mg_key);
 
     const struct sbrec_multicast_group *mg = mcgroup_lookup_by_dp_name(
@@ -180,11 +169,11 @@  is_chassis_resident_cb(const void *c_aux_, const char *port_name)
 {
     const struct condition_aux *c_aux = c_aux_;
 
-    /* Store the port name that used to lookup the lport to lflow reference, so
-     * that in the future when the lport's port-binding changes the logical
+    /* Store the port name that used to lookup the lport to object reference,
+     * so that in the future when the lport's port-binding changes the logical
      * flow that references this lport can be reprocessed. */
-    lflow_resource_add(c_aux->lfrr, REF_TYPE_PORTBINDING, port_name,
-                       &c_aux->lflow->header_.uuid, 0);
+    objdep_mgr_add(c_aux->deps_mgr, OBJDEP_TYPE_PORTBINDING, port_name,
+                   &c_aux->lflow->header_.uuid);
 
     const struct sbrec_port_binding *pb
         = lport_lookup_by_name(c_aux->sbrec_port_binding_by_name, port_name);
@@ -207,155 +196,6 @@  is_chassis_resident_cb(const void *c_aux_, const char *port_name)
     }
 }
 
-void
-lflow_resource_init(struct lflow_resource_ref *lfrr)
-{
-    hmap_init(&lfrr->ref_lflow_table);
-    hmap_init(&lfrr->lflow_ref_table);
-}
-
-void
-lflow_resource_destroy(struct lflow_resource_ref *lfrr)
-{
-    struct ref_lflow_node *rlfn;
-    HMAP_FOR_EACH_SAFE (rlfn, node, &lfrr->ref_lflow_table) {
-        struct lflow_ref_list_node *lrln;
-        HMAP_FOR_EACH_SAFE (lrln, hmap_node, &rlfn->lflow_uuids) {
-            ovs_list_remove(&lrln->list_node);
-            hmap_remove(&rlfn->lflow_uuids, &lrln->hmap_node);
-            free(lrln);
-        }
-        hmap_remove(&lfrr->ref_lflow_table, &rlfn->node);
-        ref_lflow_node_destroy(rlfn);
-    }
-    hmap_destroy(&lfrr->ref_lflow_table);
-
-    struct lflow_ref_node *lfrn;
-    HMAP_FOR_EACH_SAFE (lfrn, node, &lfrr->lflow_ref_table) {
-        hmap_remove(&lfrr->lflow_ref_table, &lfrn->node);
-        free(lfrn);
-    }
-    hmap_destroy(&lfrr->lflow_ref_table);
-}
-
-void
-lflow_resource_clear(struct lflow_resource_ref *lfrr)
-{
-    lflow_resource_destroy(lfrr);
-    lflow_resource_init(lfrr);
-}
-
-static struct ref_lflow_node*
-ref_lflow_lookup(struct hmap *ref_lflow_table,
-                 enum ref_type type, const char *ref_name)
-{
-    struct ref_lflow_node *rlfn;
-
-    HMAP_FOR_EACH_WITH_HASH (rlfn, node, hash_string(ref_name, type),
-                             ref_lflow_table) {
-        if (rlfn->type == type && !strcmp(rlfn->ref_name, ref_name)) {
-            return rlfn;
-        }
-    }
-    return NULL;
-}
-
-static struct lflow_ref_node*
-lflow_ref_lookup(struct hmap *lflow_ref_table,
-                 const struct uuid *lflow_uuid)
-{
-    struct lflow_ref_node *lfrn;
-
-    HMAP_FOR_EACH_WITH_HASH (lfrn, node, uuid_hash(lflow_uuid),
-                             lflow_ref_table) {
-        if (uuid_equals(&lfrn->lflow_uuid, lflow_uuid)) {
-            return lfrn;
-        }
-    }
-    return NULL;
-}
-
-static void
-lflow_resource_add(struct lflow_resource_ref *lfrr, enum ref_type type,
-                   const char *ref_name, const struct uuid *lflow_uuid,
-                   size_t ref_count)
-{
-    struct ref_lflow_node *rlfn = ref_lflow_lookup(&lfrr->ref_lflow_table,
-                                                   type, ref_name);
-    struct lflow_ref_node *lfrn = lflow_ref_lookup(&lfrr->lflow_ref_table,
-                                                   lflow_uuid);
-    if (rlfn && lfrn) {
-        /* Check if the mapping already existed before adding a new one. */
-        struct lflow_ref_list_node *n;
-        HMAP_FOR_EACH_WITH_HASH (n, hmap_node, uuid_hash(lflow_uuid),
-                                 &rlfn->lflow_uuids) {
-            if (uuid_equals(&n->lflow_uuid, lflow_uuid)) {
-                return;
-            }
-        }
-    }
-
-    if (!rlfn) {
-        rlfn = xzalloc(sizeof *rlfn);
-        rlfn->node.hash = hash_string(ref_name, type);
-        rlfn->type = type;
-        rlfn->ref_name = xstrdup(ref_name);
-        hmap_init(&rlfn->lflow_uuids);
-        hmap_insert(&lfrr->ref_lflow_table, &rlfn->node, rlfn->node.hash);
-    }
-
-    if (!lfrn) {
-        lfrn = xzalloc(sizeof *lfrn);
-        lfrn->node.hash = uuid_hash(lflow_uuid);
-        lfrn->lflow_uuid = *lflow_uuid;
-        ovs_list_init(&lfrn->lflow_ref_head);
-        hmap_insert(&lfrr->lflow_ref_table, &lfrn->node, lfrn->node.hash);
-    }
-
-    struct lflow_ref_list_node *lrln = xzalloc(sizeof *lrln);
-    lrln->lflow_uuid = *lflow_uuid;
-    lrln->ref_count = ref_count;
-    lrln->rlfn = rlfn;
-    hmap_insert(&rlfn->lflow_uuids, &lrln->hmap_node, uuid_hash(lflow_uuid));
-    ovs_list_push_back(&lfrn->lflow_ref_head, &lrln->list_node);
-}
-
-static void
-ref_lflow_node_destroy(struct ref_lflow_node *rlfn)
-{
-    free(rlfn->ref_name);
-    hmap_destroy(&rlfn->lflow_uuids);
-    free(rlfn);
-}
-
-static void
-lflow_resource_destroy_lflow(struct lflow_resource_ref *lfrr,
-                            const struct uuid *lflow_uuid)
-{
-    struct lflow_ref_node *lfrn = lflow_ref_lookup(&lfrr->lflow_ref_table,
-                                                   lflow_uuid);
-    if (!lfrn) {
-        return;
-    }
-
-    hmap_remove(&lfrr->lflow_ref_table, &lfrn->node);
-    struct lflow_ref_list_node *lrln;
-    LIST_FOR_EACH_SAFE (lrln, list_node, &lfrn->lflow_ref_head) {
-        ovs_list_remove(&lrln->list_node);
-        hmap_remove(&lrln->rlfn->lflow_uuids, &lrln->hmap_node);
-
-        /* Clean up the node in ref_lflow_table if the resource is not
-         * referred by any logical flows. */
-        if (hmap_is_empty(&lrln->rlfn->lflow_uuids)) {
-            hmap_remove(&lfrr->ref_lflow_table, &lrln->rlfn->node);
-            ref_lflow_node_destroy(lrln->rlfn);
-        }
-
-        free(lrln);
-    }
-    free(lfrn);
-}
-
 /* Adds the logical flows from the Logical_Flow table to flow tables. */
 static void
 add_logical_flows(struct lflow_ctx_in *l_ctx_in,
@@ -400,7 +240,7 @@  lflow_handle_changed_flows(struct lflow_ctx_in *l_ctx_in,
     struct uuidset_node *ofrn;
     UUIDSET_FOR_EACH (ofrn, &flood_remove_nodes) {
         /* Delete entries from lflow resource reference. */
-        lflow_resource_destroy_lflow(l_ctx_out->lfrr, &ofrn->uuid);
+        objdep_mgr_remove_obj(l_ctx_out->lflow_deps_mgr, &ofrn->uuid);
         /* Delete conj_ids owned by the lflow. */
         lflow_conj_ids_free(l_ctx_out->conj_ids, &ofrn->uuid);
         /* Reprocessing the lflow if the sb record is not deleted. */
@@ -537,7 +377,7 @@  consider_lflow_for_added_as_ips__(
         .sbrec_port_binding_by_name = l_ctx_in->sbrec_port_binding_by_name,
         .dp = dp,
         .lflow = lflow,
-        .lfrr = l_ctx_out->lfrr,
+        .deps_mgr = l_ctx_out->lflow_deps_mgr,
     };
     struct condition_aux cond_aux = {
         .sbrec_port_binding_by_name = l_ctx_in->sbrec_port_binding_by_name,
@@ -545,7 +385,7 @@  consider_lflow_for_added_as_ips__(
         .chassis = l_ctx_in->chassis,
         .active_tunnels = l_ctx_in->active_tunnels,
         .lflow = lflow,
-        .lfrr = l_ctx_out->lfrr,
+        .deps_mgr = l_ctx_out->lflow_deps_mgr,
     };
 
     struct hmap matches = HMAP_INITIALIZER(&matches);
@@ -591,7 +431,7 @@  consider_lflow_for_added_as_ips__(
     struct expr *expr = convert_match_to_expr(lflow, ldp, &prereqs,
                                               l_ctx_in->addr_sets,
                                               l_ctx_in->port_groups,
-                                              l_ctx_out->lfrr, NULL);
+                                              l_ctx_out->lflow_deps_mgr, NULL);
     shash_replace((struct shash *)l_ctx_in->addr_sets, as_name, real_as);
     if (new_fake_as) {
         expr_constant_set_destroy(new_fake_as);
@@ -787,10 +627,10 @@  lflow_handle_addr_set_update(const char *as_name,
         return false;
     }
 
-    struct ref_lflow_node *rlfn =
-        ref_lflow_lookup(&l_ctx_out->lfrr->ref_lflow_table, REF_TYPE_ADDRSET,
-                         as_name);
-    if (!rlfn) {
+    struct resource_to_objects_node *resource_node =
+        objdep_mgr_find_objs(l_ctx_out->lflow_deps_mgr, OBJDEP_TYPE_ADDRSET,
+                             as_name);
+    if (!resource_node) {
         *changed = false;
         return true;
     }
@@ -798,22 +638,23 @@  lflow_handle_addr_set_update(const char *as_name,
     *changed = false;
 
     bool ret = true;
-    struct lflow_ref_list_node *lrln;
-    HMAP_FOR_EACH (lrln, hmap_node, &rlfn->lflow_uuids) {
-        if (uuidset_find(l_ctx_out->lflows_processed, &lrln->lflow_uuid)) {
+    struct object_to_resources_list_node *resource_list_node;
+    RESOURCE_FOR_EACH_OBJ (resource_list_node, resource_node) {
+        const struct uuid *obj_uuid = &resource_list_node->obj_uuid;
+        if (uuidset_find(l_ctx_out->lflows_processed, obj_uuid)) {
             VLOG_DBG("lflow "UUID_FMT"has been processed, skip.",
-                     UUID_ARGS(&lrln->lflow_uuid));
+                     UUID_ARGS(obj_uuid));
             continue;
         }
         const struct sbrec_logical_flow *lflow =
             sbrec_logical_flow_table_get_for_uuid(l_ctx_in->logical_flow_table,
-                                                  &lrln->lflow_uuid);
+                                                  obj_uuid);
         if (!lflow) {
             /* lflow deletion should be handled in the corresponding input
              * handler, so we can skip here. */
             VLOG_DBG("lflow "UUID_FMT" not found while handling updates of "
                      "address set %s, skip.",
-                     UUID_ARGS(&lrln->lflow_uuid), as_name);
+                     UUID_ARGS(obj_uuid), as_name);
             continue;
         }
         *changed = true;
@@ -825,9 +666,9 @@  lflow_handle_addr_set_update(const char *as_name,
                 if (!as_info_from_expr_const(as_name, c, &as_info)) {
                     continue;
                 }
-                if (!ofctrl_remove_flows_for_as_ip(l_ctx_out->flow_table,
-                                                   &lrln->lflow_uuid, &as_info,
-                                                   lrln->ref_count)) {
+                if (!ofctrl_remove_flows_for_as_ip(
+                        l_ctx_out->flow_table, obj_uuid, &as_info,
+                        resource_list_node->ref_count)) {
                     ret = false;
                     goto done;
                 }
@@ -836,7 +677,7 @@  lflow_handle_addr_set_update(const char *as_name,
 
         if (as_diff->added) {
             if (!consider_lflow_for_added_as_ips(lflow, as_name,
-                                                 lrln->ref_count,
+                                                 resource_list_node->ref_count,
                                                  as_diff->added,
                                                  l_ctx_in, l_ctx_out)) {
                 ret = false;
@@ -850,59 +691,32 @@  done:
 }
 
 bool
-lflow_handle_changed_ref(enum ref_type ref_type, const char *ref_name,
-                         struct lflow_ctx_in *l_ctx_in,
-                         struct lflow_ctx_out *l_ctx_out,
-                         bool *changed)
+lflow_handle_changed_ref(enum objdep_type type, const char *res_name,
+                         struct ovs_list *objs_todo,
+                         const void *in_arg, void *out_arg)
 {
-    struct ref_lflow_node *rlfn =
-        ref_lflow_lookup(&l_ctx_out->lfrr->ref_lflow_table, ref_type,
-                         ref_name);
-    if (!rlfn) {
-        *changed = false;
-        return true;
-    }
-    VLOG_DBG("Handle changed lflow reference for resource type: %d,"
-             " name: %s.", ref_type, ref_name);
-    *changed = false;
-    bool ret = true;
-
-    struct ovs_list lflows_todo = OVS_LIST_INITIALIZER(&lflows_todo);
-
-    struct lflow_ref_list_node *lrln, *lrln_uuid;
-    HMAP_FOR_EACH (lrln, hmap_node, &rlfn->lflow_uuids) {
-        if (uuidset_find(l_ctx_out->lflows_processed, &lrln->lflow_uuid)) {
-            continue;
-        }
-        /* Use lflow_ref_list_node as list node to store the uuid.
-         * Other fields are not used here. */
-        lrln_uuid = xmalloc(sizeof *lrln_uuid);
-        lrln_uuid->lflow_uuid = lrln->lflow_uuid;
-        ovs_list_push_back(&lflows_todo, &lrln_uuid->list_node);
-    }
-    if (ovs_list_is_empty(&lflows_todo)) {
-        return true;
-    }
-    *changed = true;
+    struct lflow_ctx_in *l_ctx_in = CONST_CAST(struct lflow_ctx_in *, in_arg);
+    struct lflow_ctx_out *l_ctx_out = out_arg;
 
     /* Re-parse the related lflows. */
     /* Firstly, flood remove the flows from desired flow table. */
+    struct object_to_resources_list_node *resource_list_node_uuid;
     struct uuidset flood_remove_nodes =
         UUIDSET_INITIALIZER(&flood_remove_nodes);
-    LIST_FOR_EACH_SAFE (lrln_uuid, list_node, &lflows_todo) {
-        VLOG_DBG("Reprocess lflow "UUID_FMT" for resource type: %d,"
+    LIST_FOR_EACH_SAFE (resource_list_node_uuid, list_node, objs_todo) {
+        const struct uuid *obj_uuid = &resource_list_node_uuid->obj_uuid;
+        VLOG_DBG("Reprocess lflow "UUID_FMT" for resource type: %s,"
                  " name: %s.",
-                 UUID_ARGS(&lrln_uuid->lflow_uuid),
-                 ref_type, ref_name);
-        uuidset_insert(&flood_remove_nodes, &lrln_uuid->lflow_uuid);
-        free(lrln_uuid);
+                 UUID_ARGS(obj_uuid), objdep_type_name(type), res_name);
+        uuidset_insert(&flood_remove_nodes, obj_uuid);
+        free(resource_list_node_uuid);
     }
     ofctrl_flood_remove_flows(l_ctx_out->flow_table, &flood_remove_nodes);
 
     /* Secondly, for each lflow that is actually removed, reprocessing it. */
     struct uuidset_node *ofrn;
     UUIDSET_FOR_EACH (ofrn, &flood_remove_nodes) {
-        lflow_resource_destroy_lflow(l_ctx_out->lfrr, &ofrn->uuid);
+        objdep_mgr_remove_obj(l_ctx_out->lflow_deps_mgr, &ofrn->uuid);
         lflow_conj_ids_free(l_ctx_out->conj_ids, &ofrn->uuid);
 
         const struct sbrec_logical_flow *lflow =
@@ -910,9 +724,9 @@  lflow_handle_changed_ref(enum ref_type ref_type, const char *ref_name,
                                                   &ofrn->uuid);
         if (!lflow) {
             VLOG_DBG("lflow "UUID_FMT" not found while reprocessing for"
-                     " resource type: %d, name: %s.",
+                     " resource type: %s, name: %s.",
                      UUID_ARGS(&ofrn->uuid),
-                     ref_type, ref_name);
+                     objdep_type_name(type), res_name);
             continue;
         }
 
@@ -929,8 +743,7 @@  lflow_handle_changed_ref(enum ref_type ref_type, const char *ref_name,
         consider_logical_flow(lflow, false, l_ctx_in, l_ctx_out);
     }
     uuidset_destroy(&flood_remove_nodes);
-
-    return ret;
+    return true;
 }
 
 static void
@@ -985,7 +798,7 @@  add_matches_to_flow_table(const struct sbrec_logical_flow *lflow,
         .sbrec_port_binding_by_name = l_ctx_in->sbrec_port_binding_by_name,
         .dp = ldp->datapath,
         .lflow = lflow,
-        .lfrr = l_ctx_out->lfrr,
+        .deps_mgr = l_ctx_out->lflow_deps_mgr,
         .chassis_tunnels = l_ctx_in->chassis_tunnels,
     };
 
@@ -1100,7 +913,7 @@  convert_match_to_expr(const struct sbrec_logical_flow *lflow,
                       struct expr **prereqs,
                       const struct shash *addr_sets,
                       const struct shash *port_groups,
-                      struct lflow_resource_ref *lfrr,
+                      struct objdep_mgr *mgr,
                       bool *pg_addr_set_ref)
 {
     struct shash addr_sets_ref = SHASH_INITIALIZER(&addr_sets_ref);
@@ -1114,14 +927,15 @@  convert_match_to_expr(const struct sbrec_logical_flow *lflow,
                                        &error);
     struct shash_node *addr_sets_ref_node;
     SHASH_FOR_EACH (addr_sets_ref_node, &addr_sets_ref) {
-        lflow_resource_add(lfrr, REF_TYPE_ADDRSET, addr_sets_ref_node->name,
-                           &lflow->header_.uuid,
-                           *(size_t *)addr_sets_ref_node->data);
+        objdep_mgr_add_with_refcount(mgr, OBJDEP_TYPE_ADDRSET,
+                                     addr_sets_ref_node->name,
+                                     &lflow->header_.uuid,
+                                     *(size_t *) addr_sets_ref_node->data);
     }
     const char *port_group_name;
     SSET_FOR_EACH (port_group_name, &port_groups_ref) {
-        lflow_resource_add(lfrr, REF_TYPE_PORTGROUP, port_group_name,
-                           &lflow->header_.uuid, 0);
+        objdep_mgr_add(mgr, OBJDEP_TYPE_PORTGROUP, port_group_name,
+                       &lflow->header_.uuid);
     }
 
     if (pg_addr_set_ref) {
@@ -1165,8 +979,8 @@  consider_logical_flow__(const struct sbrec_logical_flow *lflow,
 
     const char *io_port = smap_get(&lflow->tags, "in_out_port");
     if (io_port) {
-        lflow_resource_add(l_ctx_out->lfrr, REF_TYPE_PORTBINDING, io_port,
-                           &lflow->header_.uuid, 0);
+        objdep_mgr_add(l_ctx_out->lflow_deps_mgr, OBJDEP_TYPE_PORTBINDING,
+                       io_port, &lflow->header_.uuid);
         const struct sbrec_port_binding *pb
             = lport_lookup_by_name(l_ctx_in->sbrec_port_binding_by_name,
                                    io_port);
@@ -1232,7 +1046,7 @@  consider_logical_flow__(const struct sbrec_logical_flow *lflow,
         .sbrec_port_binding_by_name = l_ctx_in->sbrec_port_binding_by_name,
         .dp = dp,
         .lflow = lflow,
-        .lfrr = l_ctx_out->lfrr,
+        .deps_mgr = l_ctx_out->lflow_deps_mgr,
     };
     struct condition_aux cond_aux = {
         .sbrec_port_binding_by_name = l_ctx_in->sbrec_port_binding_by_name,
@@ -1240,7 +1054,7 @@  consider_logical_flow__(const struct sbrec_logical_flow *lflow,
         .chassis = l_ctx_in->chassis,
         .active_tunnels = l_ctx_in->active_tunnels,
         .lflow = lflow,
-        .lfrr = l_ctx_out->lfrr,
+        .deps_mgr = l_ctx_out->lflow_deps_mgr,
     };
 
     struct lflow_cache_value *lcv =
@@ -1272,7 +1086,8 @@  consider_logical_flow__(const struct sbrec_logical_flow *lflow,
     switch (lcv_type) {
     case LCACHE_T_NONE:
         expr = convert_match_to_expr(lflow, ldp, &prereqs, l_ctx_in->addr_sets,
-                                     l_ctx_in->port_groups, l_ctx_out->lfrr,
+                                     l_ctx_in->port_groups,
+                                     l_ctx_out->lflow_deps_mgr,
                                      &pg_addr_set_ref);
         if (!expr) {
             goto done;
@@ -1345,8 +1160,8 @@  consider_logical_flow__(const struct sbrec_logical_flow *lflow,
         /* Cache new entry if caching is enabled. */
         if (lflow_cache_is_enabled(l_ctx_out->lflow_cache)) {
             if (cached_expr
-                && !lflow_ref_lookup(&l_ctx_out->lfrr->lflow_ref_table,
-                                     &lflow->header_.uuid)) {
+                && !objdep_mgr_contains_obj(l_ctx_out->lflow_deps_mgr,
+                                            &lflow->header_.uuid)) {
                 lflow_cache_add_matches(l_ctx_out->lflow_cache,
                                         &lflow->header_.uuid, start_conj_id,
                                         n_conjs, matches, matches_size);
@@ -2448,7 +2263,7 @@  lflow_add_flows_for_datapath(const struct sbrec_datapath_binding *dp,
                              &lflow->header_.uuid)) {
                 continue;
             }
-            /* Don't call lflows_processed_add() because here we process the
+            /* Don't call uuidset_insert() because here we process the
              * lflow only for one of the DPs in the DP group, which may be
              * incomplete. */
             consider_logical_flow__(lflow, dp, l_ctx_in, l_ctx_out);
@@ -2514,7 +2329,11 @@  lflow_handle_flows_for_lport(const struct sbrec_port_binding *pb,
 {
     bool changed;
 
-    if (!lflow_handle_changed_ref(REF_TYPE_PORTBINDING, pb->logical_port,
+    if (!objdep_mgr_handle_change(l_ctx_out->lflow_deps_mgr,
+                                  OBJDEP_TYPE_PORTBINDING,
+                                  pb->logical_port,
+                                  lflow_handle_changed_ref,
+                                  l_ctx_out->lflows_processed,
                                   l_ctx_in, l_ctx_out, &changed)) {
         return false;
     }
@@ -2549,7 +2368,11 @@  lflow_handle_changed_port_bindings(struct lflow_ctx_in *l_ctx_in,
             && !sbrec_port_binding_is_deleted(pb)) {
             continue;
         }
-        if (!lflow_handle_changed_ref(REF_TYPE_PORTBINDING, pb->logical_port,
+        if (!objdep_mgr_handle_change(l_ctx_out->lflow_deps_mgr,
+                                      OBJDEP_TYPE_PORTBINDING,
+                                      pb->logical_port,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out->lflows_processed,
                                       l_ctx_in, l_ctx_out, &changed)) {
             ret = false;
             break;
@@ -2573,7 +2396,10 @@  lflow_handle_changed_mc_groups(struct lflow_ctx_in *l_ctx_in,
             && !sbrec_multicast_group_is_deleted(mg)) {
             continue;
         }
-        if (!lflow_handle_changed_ref(REF_TYPE_MC_GROUP, ds_cstr(&mg_key),
+        if (!objdep_mgr_handle_change(l_ctx_out->lflow_deps_mgr,
+                                      OBJDEP_TYPE_MC_GROUP, ds_cstr(&mg_key),
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out->lflows_processed,
                                       l_ctx_in, l_ctx_out, &changed)) {
             ret = false;
             break;
diff --git a/controller/lflow.h b/controller/lflow.h
index 4be079555f..a7025eb23c 100644
--- a/controller/lflow.h
+++ b/controller/lflow.h
@@ -16,6 +16,9 @@ 
 #ifndef OVN_LFLOW_H
 #define OVN_LFLOW_H 1
 
+#include "lib/ovn-util.h"
+#include "lib/objdep.h"
+#include "lib/uuidset.h"
 #include "ovn/logical-fields.h"
 
 /* Logical_Flow table translation to OpenFlow
@@ -81,59 +84,6 @@  struct uuid;
 #define OFTABLE_ECMP_NH              77
 #define OFTABLE_CHK_LB_AFFINITY      78
 
-enum ref_type {
-    REF_TYPE_ADDRSET,
-    REF_TYPE_PORTGROUP,
-    REF_TYPE_PORTBINDING,
-    REF_TYPE_MC_GROUP
-};
-
-struct ref_lflow_node {
-    struct hmap_node node; /* node in lflow_resource_ref.ref_lflow_table. */
-    enum ref_type type; /* key */
-    char *ref_name; /* key */
-    struct hmap lflow_uuids; /* Contains lflow_ref_list_node. Use hmap instead
-                                of list so that lflow_resource_add() can check
-                                and avoid adding redundant entires in O(1). */
-};
-
-struct lflow_ref_node {
-    struct hmap_node node; /* node in lflow_resource_ref.lflow_ref_table. */
-    struct uuid lflow_uuid; /* key */
-    struct ovs_list lflow_ref_head; /* Contains lflow_ref_list_node. */
-};
-
-/* Maintains the relationship for a pair of named resource and
- * a lflow, indexed by both ref_lflow_table and lflow_ref_table. */
-struct lflow_ref_list_node {
-    struct ovs_list list_node; /* node in lflow_ref_node.lflow_ref_head. */
-    struct hmap_node hmap_node; /* node in ref_lflow_node.lflow_uuids. */
-    struct uuid lflow_uuid;
-    size_t ref_count; /* Reference count of the resource by this lflow.
-                         Currently used for the resource type REF_TYPE_ADDRSET
-                         only, and for other types it is always 0. */
-    struct ref_lflow_node *rlfn;
-};
-
-struct lflow_resource_ref {
-    /* A map from a referenced resource type & name (e.g. address_set AS1)
-     * to a list of lflows that are referencing the named resource. Data
-     * type of each node in this hmap is struct ref_lflow_node. The
-     * ref_lflow_head in each node points to a list of
-     * lflow_ref_list_node.ref_list. */
-    struct hmap ref_lflow_table;
-
-    /* A map from a lflow uuid to a list of named resources that are
-     * referenced by the lflow. Data type of each node in this hmap is
-     * struct lflow_ref_node. The lflow_ref_head in each node points to
-     * a list of lflow_ref_list_node.lflow_list. */
-    struct hmap lflow_ref_table;
-};
-
-void lflow_resource_init(struct lflow_resource_ref *);
-void lflow_resource_destroy(struct lflow_resource_ref *);
-void lflow_resource_clear(struct lflow_resource_ref *);
-
 struct lflow_ctx_in {
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath;
     struct ovsdb_idl_index *sbrec_logical_flow_by_logical_datapath;
@@ -170,7 +120,7 @@  struct lflow_ctx_out {
     struct ovn_desired_flow_table *flow_table;
     struct ovn_extend_table *group_table;
     struct ovn_extend_table *meter_table;
-    struct lflow_resource_ref *lfrr;
+    struct objdep_mgr *lflow_deps_mgr;
     struct lflow_cache *lflow_cache;
     struct conj_ids *conj_ids;
     struct uuidset *lflows_processed;
@@ -182,10 +132,8 @@  void lflow_init(void);
 void lflow_run(struct lflow_ctx_in *, struct lflow_ctx_out *);
 void lflow_handle_cached_flows(struct lflow_cache *,
                                const struct sbrec_logical_flow_table *);
-bool lflow_handle_changed_flows(struct lflow_ctx_in *, struct lflow_ctx_out *);
-bool lflow_handle_changed_ref(enum ref_type, const char *ref_name,
-                              struct lflow_ctx_in *, struct lflow_ctx_out *,
-                              bool *changed);
+bool lflow_handle_changed_flows(struct lflow_ctx_in *,
+                                struct lflow_ctx_out *);
 
 struct addr_set_diff {
     struct expr_constant_set *added;
@@ -195,6 +143,9 @@  bool lflow_handle_addr_set_update(const char *as_name, struct addr_set_diff *,
                                   struct lflow_ctx_in *,
                                   struct lflow_ctx_out *,
                                   bool *changed);
+bool lflow_handle_changed_ref(enum objdep_type, const char *res_name,
+                              struct ovs_list *objs_todo,
+                              const void *in_arg, void *out_arg);
 
 void lflow_handle_changed_mac_bindings(
     struct ovsdb_idl_index *sbrec_port_binding_by_name,
diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c
index 7dd83e7f47..09028d1452 100644
--- a/controller/ovn-controller.c
+++ b/controller/ovn-controller.c
@@ -2600,8 +2600,8 @@  struct ed_type_lflow_output {
     struct ovn_extend_table group_table;
     /* meter ids for QoS */
     struct ovn_extend_table meter_table;
-    /* lflow resource cross reference */
-    struct lflow_resource_ref lflow_resource_ref;
+    /* lflow <-> resource cross reference */
+    struct objdep_mgr lflow_deps_mgr;;
     /* conjunciton ID usage information of lflows */
     struct conj_ids conj_ids;
 
@@ -2760,7 +2760,7 @@  init_lflow_ctx(struct engine_node *node,
     l_ctx_out->flow_table = &fo->flow_table;
     l_ctx_out->group_table = &fo->group_table;
     l_ctx_out->meter_table = &fo->meter_table;
-    l_ctx_out->lfrr = &fo->lflow_resource_ref;
+    l_ctx_out->lflow_deps_mgr = &fo->lflow_deps_mgr;
     l_ctx_out->conj_ids = &fo->conj_ids;
     l_ctx_out->lflows_processed = &fo->lflows_processed;
     l_ctx_out->lflow_cache = fo->pd.lflow_cache;
@@ -2776,7 +2776,7 @@  en_lflow_output_init(struct engine_node *node OVS_UNUSED,
     ovn_desired_flow_table_init(&data->flow_table);
     ovn_extend_table_init(&data->group_table);
     ovn_extend_table_init(&data->meter_table);
-    lflow_resource_init(&data->lflow_resource_ref);
+    objdep_mgr_init(&data->lflow_deps_mgr);
     lflow_conj_ids_init(&data->conj_ids);
     uuidset_init(&data->lflows_processed);
     simap_init(&data->hd.ids);
@@ -2800,7 +2800,7 @@  en_lflow_output_cleanup(void *data)
     ovn_desired_flow_table_destroy(&flow_output_data->flow_table);
     ovn_extend_table_destroy(&flow_output_data->group_table);
     ovn_extend_table_destroy(&flow_output_data->meter_table);
-    lflow_resource_destroy(&flow_output_data->lflow_resource_ref);
+    objdep_mgr_destroy(&flow_output_data->lflow_deps_mgr);
     lflow_conj_ids_destroy(&flow_output_data->conj_ids);
     uuidset_destroy(&flow_output_data->lflows_processed);
     lflow_cache_destroy(flow_output_data->pd.lflow_cache);
@@ -2836,7 +2836,7 @@  en_lflow_output_run(struct engine_node *node, void *data)
     struct ovn_desired_flow_table *lflow_table = &fo->flow_table;
     struct ovn_extend_table *group_table = &fo->group_table;
     struct ovn_extend_table *meter_table = &fo->meter_table;
-    struct lflow_resource_ref *lfrr = &fo->lflow_resource_ref;
+    struct objdep_mgr *lflow_deps_mgr = &fo->lflow_deps_mgr;
 
     static bool first_run = true;
     if (first_run) {
@@ -2845,7 +2845,7 @@  en_lflow_output_run(struct engine_node *node, void *data)
         ovn_desired_flow_table_clear(lflow_table);
         ovn_extend_table_clear(group_table, false /* desired */);
         ovn_extend_table_clear(meter_table, false /* desired */);
-        lflow_resource_clear(lfrr);
+        objdep_mgr_clear(lflow_deps_mgr);
         lflow_conj_ids_clear(&fo->conj_ids);
     }
 
@@ -2976,8 +2976,11 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
     }
 
     SSET_FOR_EACH (ref_name, &as_data->deleted) {
-        if (!lflow_handle_changed_ref(REF_TYPE_ADDRSET, ref_name, &l_ctx_in,
-                                      &l_ctx_out, &changed)) {
+        if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                      OBJDEP_TYPE_ADDRSET, ref_name,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out.lflows_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
         if (changed) {
@@ -2991,7 +2994,11 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
                                           &l_ctx_out, &changed)) {
             VLOG_DBG("Can't incrementally handle the change of address set %s."
                      " Reprocess related lflows.", shash_node->name);
-            if (!lflow_handle_changed_ref(REF_TYPE_ADDRSET, shash_node->name,
+            if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                          OBJDEP_TYPE_ADDRSET,
+                                          shash_node->name,
+                                          lflow_handle_changed_ref,
+                                          l_ctx_out.lflows_processed,
                                           &l_ctx_in, &l_ctx_out, &changed)) {
                 return false;
             }
@@ -3001,8 +3008,11 @@  lflow_output_addr_sets_handler(struct engine_node *node, void *data)
         }
     }
     SSET_FOR_EACH (ref_name, &as_data->new) {
-        if (!lflow_handle_changed_ref(REF_TYPE_ADDRSET, ref_name, &l_ctx_in,
-                                      &l_ctx_out, &changed)) {
+        if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                      OBJDEP_TYPE_ADDRSET, ref_name,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out.lflows_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
         if (changed) {
@@ -3033,8 +3043,11 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
     }
 
     SSET_FOR_EACH (ref_name, &pg_data->deleted) {
-        if (!lflow_handle_changed_ref(REF_TYPE_PORTGROUP, ref_name, &l_ctx_in,
-                                      &l_ctx_out, &changed)) {
+        if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                      OBJDEP_TYPE_PORTGROUP, ref_name,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out.lflows_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
         if (changed) {
@@ -3042,8 +3055,11 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
         }
     }
     SSET_FOR_EACH (ref_name, &pg_data->updated) {
-        if (!lflow_handle_changed_ref(REF_TYPE_PORTGROUP, ref_name, &l_ctx_in,
-                                      &l_ctx_out, &changed)) {
+        if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                      OBJDEP_TYPE_PORTGROUP, ref_name,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out.lflows_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
         if (changed) {
@@ -3051,8 +3067,11 @@  lflow_output_port_groups_handler(struct engine_node *node, void *data)
         }
     }
     SSET_FOR_EACH (ref_name, &pg_data->new) {
-        if (!lflow_handle_changed_ref(REF_TYPE_PORTGROUP, ref_name, &l_ctx_in,
-                                      &l_ctx_out, &changed)) {
+        if (!objdep_mgr_handle_change(l_ctx_out.lflow_deps_mgr,
+                                      OBJDEP_TYPE_PORTGROUP, ref_name,
+                                      lflow_handle_changed_ref,
+                                      l_ctx_out.lflows_processed,
+                                      &l_ctx_in, &l_ctx_out, &changed)) {
             return false;
         }
         if (changed) {
diff --git a/lib/automake.mk b/lib/automake.mk
index 60bead6a6a..15d4f84bbb 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -31,6 +31,8 @@  lib_libovn_la_SOURCES = \
 	lib/mcast-group-index.c \
 	lib/mcast-group-index.h \
 	lib/lex.c \
+	lib/objdep.c \
+	lib/objdep.h \
 	lib/ovn-l7.h \
 	lib/ovn-l7.c \
 	lib/ovn-util.c \
diff --git a/lib/objdep.c b/lib/objdep.c
new file mode 100644
index 0000000000..092d4af261
--- /dev/null
+++ b/lib/objdep.c
@@ -0,0 +1,260 @@ 
+/* Copyright (c) 2015, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2022, Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include "lib/objdep.h"
+#include "lib/hash.h"
+#include "lib/util.h"
+#include "openvswitch/vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(resource_dep);
+
+static void resource_node_destroy(struct resource_to_objects_node *);
+
+void
+objdep_mgr_init(struct objdep_mgr *mgr)
+{
+    hmap_init(&mgr->resource_to_objects_table);
+    hmap_init(&mgr->object_to_resources_table);
+}
+
+void
+objdep_mgr_destroy(struct objdep_mgr *mgr)
+{
+    objdep_mgr_clear(mgr);
+
+    hmap_destroy(&mgr->resource_to_objects_table);
+    hmap_destroy(&mgr->object_to_resources_table);
+}
+
+void
+objdep_mgr_clear(struct objdep_mgr *mgr)
+{
+    struct resource_to_objects_node *resource_node;
+    HMAP_FOR_EACH_SAFE (resource_node, node, &mgr->resource_to_objects_table) {
+        struct object_to_resources_list_node *object_list_node;
+        HMAP_FOR_EACH_SAFE (object_list_node, hmap_node,
+                            &resource_node->objs) {
+            ovs_list_remove(&object_list_node->list_node);
+            hmap_remove(&resource_node->objs, &object_list_node->hmap_node);
+            free(object_list_node);
+        }
+        hmap_remove(&mgr->resource_to_objects_table, &resource_node->node);
+        resource_node_destroy(resource_node);
+    }
+
+    struct object_to_resources_node *object_node;
+    HMAP_FOR_EACH_SAFE (object_node, node, &mgr->object_to_resources_table) {
+        hmap_remove(&mgr->object_to_resources_table, &object_node->node);
+        free(object_node);
+    }
+}
+
+void
+objdep_mgr_add(struct objdep_mgr *mgr, enum objdep_type type,
+               const char *res_name, const struct uuid *obj_uuid)
+{
+    objdep_mgr_add_with_refcount(mgr, type, res_name, obj_uuid, 0);
+}
+
+void
+objdep_mgr_add_with_refcount(struct objdep_mgr *mgr, enum objdep_type type,
+                             const char *res_name, const struct uuid *obj_uuid,
+                             size_t ref_count)
+{
+    struct resource_to_objects_node *resource_node =
+        objdep_mgr_find_objs(mgr, type, res_name);
+    struct object_to_resources_node *object_node =
+        objdep_mgr_find_resources(mgr, obj_uuid);
+    if (resource_node && object_node) {
+        /* Check if the mapping already existed before adding a new one. */
+        struct object_to_resources_list_node *n;
+        HMAP_FOR_EACH_WITH_HASH (n, hmap_node, uuid_hash(obj_uuid),
+                                 &resource_node->objs) {
+            if (uuid_equals(&n->obj_uuid, obj_uuid)) {
+                return;
+            }
+        }
+    }
+
+    /* Create the resource node if we didn't have one already (for a
+     * different object). */
+    if (!resource_node) {
+        resource_node = xzalloc(sizeof *resource_node);
+        resource_node->node.hash = hash_string(res_name, type);
+        resource_node->type = type;
+        resource_node->res_name = xstrdup(res_name);
+        hmap_init(&resource_node->objs);
+        hmap_insert(&mgr->resource_to_objects_table,
+                    &resource_node->node,
+                    resource_node->node.hash);
+    }
+
+    /* Create the object node if we didn't have one already (for a
+     * different resource). */
+    if (!object_node) {
+        object_node = xzalloc(sizeof *object_node);
+        object_node->node.hash = uuid_hash(obj_uuid);
+        object_node->obj_uuid = *obj_uuid;
+        ovs_list_init(&object_node->resources_head);
+        hmap_insert(&mgr->object_to_resources_table,
+                    &object_node->node,
+                    object_node->node.hash);
+    }
+
+    struct object_to_resources_list_node *resource_list_node =
+        xzalloc(sizeof *resource_list_node);
+    resource_list_node->obj_uuid = *obj_uuid;
+    resource_list_node->ref_count = ref_count;
+    resource_list_node->resource_node = resource_node;
+    hmap_insert(&resource_node->objs, &resource_list_node->hmap_node,
+                uuid_hash(obj_uuid));
+    ovs_list_push_back(&object_node->resources_head,
+                       &resource_list_node->list_node);
+}
+
+void
+objdep_mgr_remove_obj(struct objdep_mgr *mgr, const struct uuid *obj_uuid)
+{
+    struct object_to_resources_node *object_node =
+        objdep_mgr_find_resources(mgr, obj_uuid);
+    if (!object_node) {
+        return;
+    }
+
+    hmap_remove(&mgr->object_to_resources_table, &object_node->node);
+
+    struct object_to_resources_list_node *resource_list_node;
+    LIST_FOR_EACH_SAFE (resource_list_node, list_node,
+                        &object_node->resources_head) {
+        struct resource_to_objects_node *resource_node =
+            resource_list_node->resource_node;
+        ovs_list_remove(&resource_list_node->list_node);
+        hmap_remove(&resource_node->objs, &resource_list_node->hmap_node);
+
+        /* Clean up the node in ref_obj_table if the resource is not
+         * referred by any logical flows. */
+        if (hmap_is_empty(&resource_node->objs)) {
+            hmap_remove(&mgr->resource_to_objects_table, &resource_node->node);
+            resource_node_destroy(resource_list_node->resource_node);
+        }
+
+        free(resource_list_node);
+    }
+    free(object_node);
+}
+
+struct resource_to_objects_node *
+objdep_mgr_find_objs(struct objdep_mgr *mgr, enum objdep_type type,
+                     const char *res_name)
+{
+    struct resource_to_objects_node *resource_node;
+
+    HMAP_FOR_EACH_WITH_HASH (resource_node, node, hash_string(res_name, type),
+                             &mgr->resource_to_objects_table) {
+        if (resource_node->type == type &&
+                !strcmp(resource_node->res_name, res_name)) {
+            return resource_node;
+        }
+    }
+    return NULL;
+}
+
+struct object_to_resources_node *
+objdep_mgr_find_resources(struct objdep_mgr *mgr,
+                          const struct uuid *obj_uuid)
+{
+    struct object_to_resources_node *object_node;
+
+    HMAP_FOR_EACH_WITH_HASH (object_node, node, uuid_hash(obj_uuid),
+                             &mgr->object_to_resources_table) {
+        if (uuid_equals(&object_node->obj_uuid, obj_uuid)) {
+            return object_node;
+        }
+    }
+    return NULL;
+}
+
+bool
+objdep_mgr_contains_obj(struct objdep_mgr *mgr, const struct uuid *obj_uuid)
+{
+    return !!objdep_mgr_find_resources(mgr, obj_uuid);
+}
+
+bool
+objdep_mgr_handle_change(struct objdep_mgr *mgr,
+                         enum objdep_type type,
+                         const char *res_name,
+                         objdep_change_handler handler,
+                         struct uuidset *objs_processed,
+                         const void *in_arg, void *out_arg,
+                         bool *changed)
+{
+    struct resource_to_objects_node *resource_node =
+        objdep_mgr_find_objs(mgr, type, res_name);
+    if (!resource_node) {
+        *changed = false;
+        return true;
+    }
+    VLOG_DBG("Handle changed object reference for resource type: %s,"
+             " name: %s.", objdep_type_name(type), res_name);
+    *changed = false;
+
+    struct ovs_list objs_todo = OVS_LIST_INITIALIZER(&objs_todo);
+
+    struct object_to_resources_list_node *resource_list_node;
+    HMAP_FOR_EACH (resource_list_node, hmap_node, &resource_node->objs) {
+        if (uuidset_find(objs_processed, &resource_list_node->obj_uuid)) {
+            continue;
+        }
+        /* Use object_to_resources_list_node as list node to store the uuid.
+         * Other fields are not used here. */
+        struct object_to_resources_list_node *resource_list_node_uuid =
+            xmalloc(sizeof *resource_list_node_uuid);
+        resource_list_node_uuid->obj_uuid = resource_list_node->obj_uuid;
+        ovs_list_push_back(&objs_todo, &resource_list_node_uuid->list_node);
+    }
+    if (ovs_list_is_empty(&objs_todo)) {
+        return true;
+    }
+    *changed = true;
+
+    /* This takes ownership of objs_todo. */
+    return handler(type, res_name, &objs_todo, in_arg, out_arg);
+}
+
+const char *
+objdep_type_name(enum objdep_type type)
+{
+    static const char *type_names[OBJDEP_TYPE_MAX] = {
+        [OBJDEP_TYPE_ADDRSET] = "Address_Set",
+        [OBJDEP_TYPE_PORTGROUP] = "Port_Group",
+        [OBJDEP_TYPE_PORTBINDING] = "Port_Binding",
+        [OBJDEP_TYPE_MC_GROUP] = "Multicast_Group",
+    };
+
+    ovs_assert(type < OBJDEP_TYPE_MAX);
+    return type_names[type];
+}
+
+static void
+resource_node_destroy(struct resource_to_objects_node *resource_node)
+{
+    free(resource_node->res_name);
+    hmap_destroy(&resource_node->objs);
+    free(resource_node);
+}
diff --git a/lib/objdep.h b/lib/objdep.h
new file mode 100644
index 0000000000..50c7b01ef1
--- /dev/null
+++ b/lib/objdep.h
@@ -0,0 +1,122 @@ 
+/* Copyright (c) 2015, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2022, Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef OVN_OBJDEP_H
+#define OVN_OBJDEP_H 1
+
+#include "lib/uuidset.h"
+#include "openvswitch/hmap.h"
+#include "openvswitch/list.h"
+
+enum objdep_type {
+    OBJDEP_TYPE_ADDRSET,
+    OBJDEP_TYPE_PORTGROUP,
+    OBJDEP_TYPE_PORTBINDING,
+    OBJDEP_TYPE_MC_GROUP,
+    OBJDEP_TYPE_MAX,
+};
+
+/* Callbacks provided by users to process changes to resources referred by
+ * various objects.  They should return true if the change has been
+ * handled successfully. */
+typedef bool (*objdep_change_handler)(enum objdep_type,
+                                      const char *res_name,
+                                      struct ovs_list *ref_nodes,
+                                      const void *in_arg, void *out_arg);
+
+/* A node pointing to all objects that refer to a given resource. */
+struct resource_to_objects_node {
+    struct hmap_node node; /* node in objdep_mgr.resource_to_objects_table. */
+    enum objdep_type type; /* key */
+    char *res_name;        /* key */
+    struct hmap objs;      /* Contains object_to_resources_list_node.
+                            * Use hmap instead of list so
+                            * that obj_resource_add() can check and avoid
+                            * and redundant entries in O(1). */
+};
+
+#define RESOURCE_FOR_EACH_OBJ(NODE, MAP) \
+    HMAP_FOR_EACH (NODE, hmap_node, &(MAP)->objs)
+
+/* A node pointing to all resources used by a given object (specified by
+ * uuid).
+ */
+struct object_to_resources_node {
+    struct hmap_node node; /* node in objdep_mgr.object_to_resources_table. */
+    struct uuid obj_uuid;  /* key */
+    struct ovs_list resources_head; /* Contains elements of type
+                                     * object_to_resources_list_node. */
+};
+
+/* Maintains the relationship for a pair of named resource and
+ * an object, indexed by both resource_to_object_table and
+ * object_to_resources_table. */
+struct object_to_resources_list_node {
+    /* node in object_to_resources_node.resources_head. */
+    struct ovs_list list_node;
+    struct hmap_node hmap_node; /* node in resource_to_objects_node.objs. */
+    struct uuid obj_uuid;
+    size_t ref_count; /* Reference count of the resource by this object.
+                       * Currently only used for the resource type
+                       * OBJDEP_TYPE_ADDRSET and for other types always
+                       * set to 0. */
+    struct resource_to_objects_node *resource_node;
+};
+
+struct objdep_mgr {
+    /* A map from a referenced resource type & name (e.g. address_set AS1)
+     * to a list of object UUIDs (e.g., lflow) that are referencing the named
+     * resource. Data type of each node in this hmap is struct
+     * resource_to_objects_node.  The objs in each node point
+     * to a map of object_to_resources_list_node.ref_list. */
+    struct hmap resource_to_objects_table;
+
+    /* A map from a obj uuid to a list of named resources that are
+     * referenced by the object. Data type of each node in this hmap is
+     * struct object_to_resources_node. The resources_head in each node
+     * points to a list of object_to_resources_list_node.obj_list. */
+    struct hmap object_to_resources_table;
+};
+
+void objdep_mgr_init(struct objdep_mgr *);
+void objdep_mgr_destroy(struct objdep_mgr *);
+void objdep_mgr_clear(struct objdep_mgr *);
+
+void objdep_mgr_add(struct objdep_mgr *, enum objdep_type,
+                    const char *res_name, const struct uuid *);
+void objdep_mgr_add_with_refcount(struct objdep_mgr *,
+                                  enum objdep_type,
+                                  const char *res_name,
+                                  const struct uuid *,
+                                  size_t ref_count);
+void objdep_mgr_remove_obj(struct objdep_mgr *, const struct uuid *);
+
+struct resource_to_objects_node *objdep_mgr_find_objs(
+    struct objdep_mgr *, enum objdep_type, const char *res_name);
+struct object_to_resources_node *objdep_mgr_find_resources(
+    struct objdep_mgr *, const struct uuid *);
+bool objdep_mgr_contains_obj(struct objdep_mgr *, const struct uuid *);
+
+bool objdep_mgr_handle_change(struct objdep_mgr *, enum objdep_type,
+                              const char *res_name,
+                              objdep_change_handler handler,
+                              struct uuidset *objs_processed,
+                              const void *in_arg, void *out_arg,
+                              bool *changed);
+
+const char *objdep_type_name(enum objdep_type);
+
+#endif /* lib/objdep.h */