lib/dns/masterdump.c: use isc_refcount_t and atomics

diff --git a/lib/dns/masterdump.c b/lib/dns/masterdump.c
index 64e7ee494fb6c4a25de13d2144dc2cdd92f85bb5..4177adff752918ccfee33f40189d47192e053c91 100644 (file)
--- a/lib/dns/masterdump.c
+++ b/lib/dns/masterdump.c
@@ -15,11 +15,13 @@
 #include <stdbool.h>
 #include <stdlib.h>
 
+#include <isc/atomic.h>
 #include <isc/buffer.h>
 #include <isc/event.h>
 #include <isc/file.h>
 #include <isc/magic.h>
 #include <isc/mem.h>
+#include <isc/refcount.h>
 #include <isc/print.h>
 #include <isc/stdio.h>
 #include <isc/string.h>
@@ -221,10 +223,10 @@ struct dns_dumpctx {
        unsigned int            magic;
        isc_mem_t               *mctx;
        isc_mutex_t             lock;
-       unsigned int            references;
-       bool            canceled;
-       bool            first;
-       bool            do_date;
+       isc_refcount_t          references;
+       atomic_bool             canceled;
+       bool                    first;
+       bool                    do_date;
        isc_stdtime_t           now;
        FILE                    *f;
        dns_db_t                *db;
@@ -1291,11 +1293,7 @@ dns_dumpctx_attach(dns_dumpctx_t *source, dns_dumpctx_t **target) {
        REQUIRE(DNS_DCTX_VALID(source));
        REQUIRE(target != NULL && *target == NULL);
 
-       LOCK(&source->lock);
-       INSIST(source->references > 0);
-       source->references++;
-       INSIST(source->references != 0);        /* Overflow? */
-       UNLOCK(&source->lock);
+       isc_refcount_increment(&source->references);
 
        *target = source;
 }
@@ -1303,7 +1301,6 @@ dns_dumpctx_attach(dns_dumpctx_t *source, dns_dumpctx_t **target) {
 void
 dns_dumpctx_detach(dns_dumpctx_t **dctxp) {
        dns_dumpctx_t *dctx;
-       bool need_destroy = false;
 
        REQUIRE(dctxp != NULL);
        dctx = *dctxp;
@@ -1311,14 +1308,9 @@ dns_dumpctx_detach(dns_dumpctx_t **dctxp) {
 
        *dctxp = NULL;
 
-       LOCK(&dctx->lock);
-       INSIST(dctx->references != 0);
-       dctx->references--;
-       if (dctx->references == 0)
-               need_destroy = true;
-       UNLOCK(&dctx->lock);
-       if (need_destroy)
+       if (isc_refcount_decrement(&dctx->references) == 1) {
                dumpctx_destroy(dctx);
+       }
 }
 
 dns_dbversion_t *
@@ -1337,9 +1329,7 @@ void
 dns_dumpctx_cancel(dns_dumpctx_t *dctx) {
        REQUIRE(DNS_DCTX_VALID(dctx));
 
-       LOCK(&dctx->lock);
-       dctx->canceled = true;
-       UNLOCK(&dctx->lock);
+       atomic_store_release(&dctx->canceled, true);
 }
 
 static isc_result_t
@@ -1421,10 +1411,11 @@ dump_quantum(isc_task_t *task, isc_event_t *event) {
        REQUIRE(event != NULL);
        dctx = event->ev_arg;
        REQUIRE(DNS_DCTX_VALID(dctx));
-       if (dctx->canceled)
+       if (atomic_load_acquire(&dctx->canceled)) {
                result = ISC_R_CANCELED;
-       else
+       } else {
                result = dumptostreaminc(dctx);
+       }
        if (result == DNS_R_CONTINUE) {
                event->ev_arg = dctx;
                isc_task_send(task, &event);
@@ -1478,7 +1469,7 @@ dumpctx_create(isc_mem_t *mctx, dns_db_t *db, dns_dbversion_t *version,
        dctx->task = NULL;
        dctx->nodes = 0;
        dctx->first = true;
-       dctx->canceled = false;
+       atomic_init(&dctx->canceled, false);
        dctx->file = NULL;
        dctx->tmpfile = NULL;
        dctx->format = format;
@@ -1540,7 +1531,8 @@ dumpctx_create(isc_mem_t *mctx, dns_db_t *db, dns_dbversion_t *version,
        else if (!dns_db_iscache(db))
                dns_db_currentversion(dctx->db, &dctx->version);
        isc_mem_attach(mctx, &dctx->mctx);
-       dctx->references = 1;
+
+       isc_refcount_init(&dctx->references, 1);
        dctx->magic = DNS_DCTX_MAGIC;
        *dctxp = dctx;
        return (ISC_R_SUCCESS);