Use dns_keytable_attachkeynode() and switch to C11 atomics for .active_nodes

diff --git a/lib/dns/keytable.c b/lib/dns/keytable.c
index cdc54071e71127e48356e02c63a5113612800109..60c3275f50aaa0e0c5dc9ad94e2748f0c3d6b8ca 100644 (file)
--- a/lib/dns/keytable.c
+++ b/lib/dns/keytable.c
@@ -40,7 +40,7 @@ struct dns_keytable {
        /* Unlocked. */
        unsigned int            magic;
        isc_mem_t               *mctx;
-       isc_refcount_t          active_nodes;
+       atomic_uint_fast32_t    active_nodes;
        isc_refcount_t          references;
        isc_rwlock_t            rwlock;
        /* Locked by rwlock. */
@@ -90,7 +90,7 @@ dns_keytable_create(isc_mem_t *mctx, dns_keytable_t **keytablep) {
                goto cleanup_rbt;
        }
 
-       isc_refcount_init(&keytable->active_nodes, 0);
+       atomic_init(&keytable->active_nodes, 0);
        isc_refcount_init(&keytable->references, 1);
 
        keytable->mctx = NULL;
@@ -132,7 +132,7 @@ dns_keytable_detach(dns_keytable_t **keytablep) {
 
        if (isc_refcount_decrement(&keytable->references) == 1) {
                isc_refcount_destroy(&keytable->references);
-               isc_refcount_destroy(&keytable->active_nodes);
+               REQUIRE(atomic_load_acquire(&keytable->active_nodes) == 0);
                dns_rbt_destroy(&keytable->table);
                isc_rwlock_destroy(&keytable->rwlock);
                keytable->magic = 0;
@@ -481,12 +481,14 @@ dns_keytable_find(dns_keytable_t *keytable, const dns_name_t *keyname,
                                  DNS_RBTFIND_NOOPTIONS, NULL, NULL);
        if (result == ISC_R_SUCCESS) {
                if (node->data != NULL) {
-                       isc_refcount_increment0(&keytable->active_nodes);
-                       dns_keynode_attach(node->data, keynodep);
-               } else
+                       dns_keytable_attachkeynode(keytable, node->data,
+                                                  keynodep);
+               } else {
                        result = ISC_R_NOTFOUND;
-       } else if (result == DNS_R_PARTIALMATCH)
+               }
+       } else if (result == DNS_R_PARTIALMATCH) {
                result = ISC_R_NOTFOUND;
+       }
        RWUNLOCK(&keytable->rwlock, isc_rwlocktype_read);
 
        return (result);
@@ -509,8 +511,7 @@ dns_keytable_nextkeynode(dns_keytable_t *keytable, dns_keynode_t *keynode,
                return (ISC_R_NOTFOUND);
        }
 
-       dns_keynode_attach(keynode->next, nextnodep);
-       isc_refcount_increment(&keytable->active_nodes);
+       dns_keytable_attachkeynode(keytable, keynode->next, nextnodep);
 
        return (ISC_R_SUCCESS);
 }
@@ -560,8 +561,7 @@ dns_keytable_findkeynode(dns_keytable_t *keytable, const dns_name_t *name,
                        }
                }
                if (knode != NULL) {
-                       isc_refcount_increment0(&keytable->active_nodes);
-                       dns_keynode_attach(knode, keynodep);
+                       dns_keytable_attachkeynode(keytable, knode, keynodep);
                } else {
                        result = DNS_R_PARTIALMATCH;
                }
@@ -602,9 +602,8 @@ dns_keytable_findnextkeynode(dns_keytable_t *keytable, dns_keynode_t *keynode,
                }
        }
        if (knode != NULL) {
-               isc_refcount_increment(&keytable->active_nodes);
+               dns_keytable_attachkeynode(keytable, knode, nextnodep);
                result = ISC_R_SUCCESS;
-               dns_keynode_attach(knode, nextnodep);
        } else {
                result = ISC_R_NOTFOUND;
        }
@@ -653,7 +652,7 @@ dns_keytable_attachkeynode(dns_keytable_t *keytable, dns_keynode_t *source,
        REQUIRE(VALID_KEYNODE(source));
        REQUIRE(target != NULL && *target == NULL);
 
-       isc_refcount_increment(&keytable->active_nodes);
+       REQUIRE(atomic_fetch_add_relaxed(&keytable->active_nodes, 1) < UINT32_MAX);
 
        dns_keynode_attach(source, target);
 }
@@ -668,7 +667,8 @@ dns_keytable_detachkeynode(dns_keytable_t *keytable, dns_keynode_t **keynodep)
        REQUIRE(VALID_KEYTABLE(keytable));
        REQUIRE(keynodep != NULL && VALID_KEYNODE(*keynodep));
 
-       INSIST(isc_refcount_decrement(&keytable->active_nodes) > 0);
+       REQUIRE(atomic_fetch_sub_release(&keytable->active_nodes, 1) > 0);
+
        dns_keynode_detach(keytable->mctx, keynodep);
 }
 
@@ -891,7 +891,8 @@ dns_keytable_forall(dns_keytable_t *keytable,
                }
                goto cleanup;
        }
-       isc_refcount_increment0(&keytable->active_nodes);
+       REQUIRE(atomic_fetch_add_relaxed(&keytable->active_nodes, 1)
+               < UINT32_MAX);
        for (;;) {
                dns_rbtnodechain_current(&chain, foundname, origin, &node);
                if (node->data != NULL) {
@@ -908,7 +909,7 @@ dns_keytable_forall(dns_keytable_t *keytable,
                        break;
                }
        }
-       INSIST(isc_refcount_decrement(&keytable->active_nodes) > 0);
+       REQUIRE(atomic_fetch_sub_release(&keytable->active_nodes, 1) > 0);
 
    cleanup:
        dns_rbtnodechain_invalidate(&chain);