lib/dns/ecdb.c: use isc_refcount_t

diff --git a/lib/dns/ecdb.c b/lib/dns/ecdb.c
index 97711956b83cd7241c1b0842a8670bfe9c8df0ef..fc349e82c67cf58cf00bddc163dd994fb2ff3c04 100644 (file)
--- a/lib/dns/ecdb.c
+++ b/lib/dns/ecdb.c
@@ -11,6 +11,7 @@
 
 #include <stdbool.h>
 
+#include <isc/refcount.h>
 #include <isc/result.h>
 #include <isc/util.h>
 #include <isc/mutex.h>
@@ -43,8 +44,10 @@ typedef struct dns_ecdb {
        dns_db_t                        common;
        isc_mutex_t                     lock;
 
+       /* Protected by atomics */
+       isc_refcount_t                  references;
+
        /* Locked */
-       unsigned int                    references;
        ISC_LIST(struct dns_ecdbnode)   nodes;
 } dns_ecdb_t;
 
@@ -58,7 +61,9 @@ typedef struct dns_ecdbnode {
 
        /* Locked */
        ISC_LIST(struct rdatasetheader) rdatasets;
-       unsigned int                    references;
+
+       /* Protected by atomics */
+       isc_refcount_t                  references;
 } dns_ecdbnode_t;
 
 typedef struct rdatasetheader {
@@ -156,9 +161,7 @@ attach(dns_db_t *source, dns_db_t **targetp) {
        REQUIRE(VALID_ECDB(ecdb));
        REQUIRE(targetp != NULL && *targetp == NULL);
 
-       LOCK(&ecdb->lock);
-       ecdb->references++;
-       UNLOCK(&ecdb->lock);
+       isc_refcount_increment(&ecdb->references);
 
        *targetp = source;
 }
@@ -172,6 +175,7 @@ destroy_ecdb(dns_ecdb_t **ecdbp) {
                dns_name_free(&ecdb->common.origin, mctx);
 
        isc_mutex_destroy(&ecdb->lock);
+       isc_refcount_destroy(&ecdb->references);
 
        ecdb->common.impmagic = 0;
        ecdb->common.magic = 0;
@@ -191,9 +195,10 @@ detach(dns_db_t **dbp) {
        REQUIRE(VALID_ECDB(ecdb));
 
        LOCK(&ecdb->lock);
-       ecdb->references--;
-       if (ecdb->references == 0 && ISC_LIST_EMPTY(ecdb->nodes))
+       if (isc_refcount_decrement(&ecdb->references) == 1 &&
+           ISC_LIST_EMPTY(ecdb->nodes)) {
                need_destroy = true;
+       }
        UNLOCK(&ecdb->lock);
 
        if (need_destroy)
@@ -211,11 +216,7 @@ attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) {
        REQUIRE(VALID_ECDBNODE(node));
        REQUIRE(targetp != NULL && *targetp == NULL);
 
-       LOCK(&node->lock);
-       INSIST(node->references > 0);
-       node->references++;
-       INSIST(node->references != 0);          /* Catch overflow. */
-       UNLOCK(&node->lock);
+       isc_refcount_increment(&node->references);
 
        *targetp = node;
 }
@@ -231,8 +232,10 @@ destroynode(dns_ecdbnode_t *node) {
 
        LOCK(&ecdb->lock);
        ISC_LIST_UNLINK(ecdb->nodes, node, link);
-       if (ecdb->references == 0 && ISC_LIST_EMPTY(ecdb->nodes))
+       if (isc_refcount_current(&ecdb->references) == 0 &&
+           ISC_LIST_EMPTY(ecdb->nodes)) {
                need_destroydb = true;
+       }
        UNLOCK(&ecdb->lock);
 
        dns_name_free(&node->name, mctx);
@@ -248,6 +251,7 @@ destroynode(dns_ecdbnode_t *node) {
        }
 
        isc_mutex_destroy(&node->lock);
+       isc_refcount_destroy(&node->references);
 
        node->magic = 0;
        isc_mem_put(mctx, node, sizeof(*node));
@@ -260,26 +264,16 @@ static void
 detachnode(dns_db_t *db, dns_dbnode_t **nodep) {
        dns_ecdb_t *ecdb = (dns_ecdb_t *)db;
        dns_ecdbnode_t *node;
-       bool need_destroy = false;
 
        REQUIRE(VALID_ECDB(ecdb));
        REQUIRE(nodep != NULL);
        node = (dns_ecdbnode_t *)*nodep;
        REQUIRE(VALID_ECDBNODE(node));
+       *nodep = NULL;
 
-       UNUSED(ecdb);           /* in case REQUIRE() is empty */
-
-       LOCK(&node->lock);
-       INSIST(node->references > 0);
-       node->references--;
-       if (node->references == 0)
-               need_destroy = true;
-       UNLOCK(&node->lock);
-
-       if (need_destroy)
+       if (isc_refcount_decrement(&node->references) == 1) {
                destroynode(node);
-
-       *nodep = NULL;
+       }
 }
 
 static isc_result_t
@@ -362,7 +356,7 @@ findnode(dns_db_t *db, const dns_name_t *name, bool create,
                return (result);
        }
        node->ecdb= ecdb;
-       node->references = 1;
+       isc_refcount_init(&node->references, 1);
        ISC_LIST_INIT(node->rdatasets);
 
        ISC_LINK_INIT(node, link);
@@ -413,8 +407,7 @@ bind_rdataset(dns_ecdb_t *ecdb, dns_ecdbnode_t *node,
        rdataset->privateuint4 = 0;
        rdataset->private5 = NULL;
 
-       INSIST(node->references > 0);
-       node->references++;
+       isc_refcount_increment(&node->references);
 }
 
 static isc_result_t
@@ -618,7 +611,7 @@ dns_ecdb_create(isc_mem_t *mctx, const dns_name_t *origin, dns_dbtype_t type,
 
        isc_mutex_init(&ecdb->lock);
 
-       ecdb->references = 1;
+       isc_refcount_init(&ecdb->references, 1);
        ISC_LIST_INIT(ecdb->nodes);
 
        ecdb->common.mctx = NULL;