From 2a57d0b00cfbad53a1e0157073d059cba724e0a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@sury.org>
Date: Mon, 20 May 2019 16:54:46 +0200
Subject: [PATCH] lib/dns/ssu.c: use isc_refcount_t

---
 lib/dns/ssu.c | 31 +++++++------------------------
 1 file changed, 7 insertions(+), 24 deletions(-)

diff --git a/lib/dns/ssu.c b/lib/dns/ssu.c
index 73e8da4e2a..0e93a657dc 100644
--- a/lib/dns/ssu.c
+++ b/lib/dns/ssu.c
@@ -17,6 +17,7 @@
 #include <isc/mem.h>
 #include <isc/netaddr.h>
 #include <isc/print.h>
+#include <isc/refcount.h>
 #include <isc/result.h>
 #include <isc/string.h>
 #include <isc/util.h>
@@ -51,8 +52,7 @@ struct dns_ssurule {
 struct dns_ssutable {
 	unsigned int magic;
 	isc_mem_t *mctx;
-	unsigned int references;
-	isc_mutex_t lock;
+	isc_refcount_t references;
 	dns_dlzdb_t *dlzdatabase;
 	ISC_LIST(dns_ssurule_t) rules;
 };
@@ -65,10 +65,7 @@ dns_ssutable_create(isc_mem_t *mctx, dns_ssutable_t **tablep) {
 	REQUIRE(mctx != NULL);
 
 	table = isc_mem_get(mctx, sizeof(dns_ssutable_t));
-	if (table == NULL)
-		return (ISC_R_NOMEMORY);
-	isc_mutex_init(&table->lock);
-	table->references = 1;
+	isc_refcount_init(&table->references, 1);
 	table->mctx = NULL;
 	isc_mem_attach(mctx, &table->mctx);
 	ISC_LIST_INIT(table->rules);
@@ -101,7 +98,7 @@ destroy(dns_ssutable_t *table) {
 		rule->magic = 0;
 		isc_mem_put(mctx, rule, sizeof(dns_ssurule_t));
 	}
-	isc_mutex_destroy(&table->lock);
+	isc_refcount_destroy(&table->references);
 	table->magic = 0;
 	isc_mem_putanddetach(&table->mctx, table, sizeof(dns_ssutable_t));
 }
@@ -111,13 +108,7 @@ dns_ssutable_attach(dns_ssutable_t *source, dns_ssutable_t **targetp) {
 	REQUIRE(VALID_SSUTABLE(source));
 	REQUIRE(targetp != NULL && *targetp == NULL);
 
-	LOCK(&source->lock);
-
-	INSIST(source->references > 0);
-	source->references++;
-	INSIST(source->references != 0);
-
-	UNLOCK(&source->lock);
+	isc_refcount_increment(&source->references);
 
 	*targetp = source;
 }
@@ -125,23 +116,15 @@ dns_ssutable_attach(dns_ssutable_t *source, dns_ssutable_t **targetp) {
 void
 dns_ssutable_detach(dns_ssutable_t **tablep) {
 	dns_ssutable_t *table;
-	bool done = false;
 
 	REQUIRE(tablep != NULL);
 	table = *tablep;
 	REQUIRE(VALID_SSUTABLE(table));
-
-	LOCK(&table->lock);
-
-	INSIST(table->references > 0);
-	if (--table->references == 0)
-		done = true;
-	UNLOCK(&table->lock);
-
 	*tablep = NULL;
 
-	if (done)
+	if (isc_refcount_decrement(&table->references) == 1) {
 		destroy(table);
+	}
 }
 
 isc_result_t