Use regular reference counting macro for isc_nm_t structure

Instead of having hand crafted attach/detach/destroy functions, replace
them with the standard ISC_REFCOUNT macro.  This also have advantage
that delayed netmgr detach (from dns_dispatch) now doesn't cause
assertion failure.  This can happen with delayed (call_rcu) shutdown of
dns_adb.

lib/isc/include/isc/netmgr.h

@@ -123,16 +123,17 @@ isc_netmgr_create(isc_mem_t *mctx, isc_loopmgr_t *loopmgr, isc_nm_t **netgmrp);
  * Creates a new network manager and starts it running when loopmgr is started.
  */
 
-void
+#if ISC_NETMGR_TRACE
-isc_netmgr_destroy(isc_nm_t **netmgrp);
+#define isc_nm_ref(ptr)	  isc_nm__ref(ptr, __func__, __FILE__, __LINE__)
-/*%<
+#define isc_nm_unref(ptr) isc_nm__unref(ptr, __func__, __FILE__, __LINE__)
- * Similar to isc_nm_detach(), but requires all other references to be gone.
+#define isc_nm_attach(ptr, ptrp) \
- */
+	isc_nm__attach(ptr, ptrp, __func__, __FILE__, __LINE__)
+#define isc_nm_detach(ptrp) isc_nm__detach(ptrp, __func__, __FILE__, __LINE__)
+ISC_REFCOUNT_TRACE_DECL(isc_nm);
+#else
+ISC_REFCOUNT_DECL(isc_nm);
+#endif
 
-void
-isc_nm_attach(isc_nm_t *mgr, isc_nm_t **dst);
-void
-isc_nm_detach(isc_nm_t **mgr0);
 /*%<
  * Attach/detach a network manager. When all references have been
  * released, the network manager is shut down, freeing all resources.

lib/isc/managers.c

@@ -45,7 +45,7 @@ isc_managers_destroy(isc_mem_t **mctxp, isc_loopmgr_t **loopmgrp,
 	 * The sequence of operations here is important:
 	 */
 
-	isc_netmgr_destroy(netmgrp);
+	isc_nm_detach(netmgrp);
 	isc_loopmgr_destroy(loopmgrp);
 	isc_mem_detach(mctxp);
 }

lib/isc/netmgr/netmgr.c

@@ -244,62 +244,27 @@ isc_netmgr_create(isc_mem_t *mctx, isc_loopmgr_t *loopmgr, isc_nm_t **netmgrp) {
  * Free the resources of the network manager.
  */
 static void
-nm_destroy(isc_nm_t **mgr0) {
+nm_destroy(isc_nm_t *netmgr) {
-	REQUIRE(VALID_NM(*mgr0));
+	REQUIRE(VALID_NM(netmgr));
 
-	isc_nm_t *mgr = *mgr0;
+	isc_refcount_destroy(&netmgr->references);
-	*mgr0 = NULL;
 
-	isc_refcount_destroy(&mgr->references);
+	netmgr->magic = 0;
 
-	mgr->magic = 0;
+	if (netmgr->stats != NULL) {
-
+		isc_stats_detach(&netmgr->stats);
-	if (mgr->stats != NULL) {
-		isc_stats_detach(&mgr->stats);
 	}
 
-	isc_mem_cput(mgr->mctx, mgr->workers, mgr->nloops,
+	isc_mem_cput(netmgr->mctx, netmgr->workers, netmgr->nloops,
-		     sizeof(mgr->workers[0]));
+		     sizeof(netmgr->workers[0]));
-	isc_mem_putanddetach(&mgr->mctx, mgr, sizeof(*mgr));
+	isc_mem_putanddetach(&netmgr->mctx, netmgr, sizeof(*netmgr));
 }
 
-void
+#if ISC_NETMGR_TRACE
-isc_nm_attach(isc_nm_t *mgr, isc_nm_t **dst) {
+ISC_REFCOUNT_TRACE_IMPL(isc_nm, nm_destroy)
-	REQUIRE(VALID_NM(mgr));
+#else
-	REQUIRE(dst != NULL && *dst == NULL);
+ISC_REFCOUNT_IMPL(isc_nm, nm_destroy);
-
+#endif
-	isc_refcount_increment(&mgr->references);
-
-	*dst = mgr;
-}
-
-void
-isc_nm_detach(isc_nm_t **mgr0) {
-	isc_nm_t *mgr = NULL;
-
-	REQUIRE(mgr0 != NULL);
-	REQUIRE(VALID_NM(*mgr0));
-
-	mgr = *mgr0;
-	*mgr0 = NULL;
-
-	if (isc_refcount_decrement(&mgr->references) == 1) {
-		nm_destroy(&mgr);
-	}
-}
-
-void
-isc_netmgr_destroy(isc_nm_t **netmgrp) {
-	isc_nm_t *mgr = NULL;
-
-	REQUIRE(VALID_NM(*netmgrp));
-
-	mgr = *netmgrp;
-	*netmgrp = NULL;
-
-	REQUIRE(isc_refcount_decrement(&mgr->references) == 1);
-	nm_destroy(&mgr);
-}
 
 void
 isc_nm_maxudp(isc_nm_t *mgr, uint32_t maxudp) {

tests/dns/dispatch_test.c

@@ -245,7 +245,7 @@ teardown_test(void **state) {
 	isc_tlsctx_cache_detach(&tls_tlsctx_client_cache);
 	isc_tlsctx_free(&tls_listen_tlsctx);
 
-	isc_netmgr_destroy(&connect_nm);
+	isc_nm_detach(&connect_nm);
 
 	teardown_netmgr(state);
 	teardown_loopmgr(state);

tests/isc/doh_test.c

@@ -377,7 +377,7 @@ setup_test(void **state) {
 static int
 teardown_test(void **state ISC_ATTR_UNUSED) {
 	for (size_t i = 0; i < MAX_NM; i++) {
-		isc_netmgr_destroy(&nm[i]);
+		isc_nm_detach(&nm[i]);
 		assert_null(nm[i]);
 	}
 	isc_mem_cput(mctx, nm, MAX_NM, sizeof(nm[0]));

tests/isc/netmgr_common.c

@@ -226,10 +226,10 @@ teardown_netmgr_test(void **state ISC_ATTR_UNUSED) {
 	isc_tlsctx_free(&tcp_connect_tlsctx);
 	isc_tlsctx_free(&tcp_listen_tlsctx);
 
-	isc_netmgr_destroy(&connect_nm);
+	isc_nm_detach(&connect_nm);
 	assert_null(connect_nm);
 
-	isc_netmgr_destroy(&listen_nm);
+	isc_nm_detach(&listen_nm);
 	assert_null(listen_nm);
 
 	teardown_loopmgr(state);

tests/libtest/isc.c

@@ -121,7 +121,7 @@ int
 teardown_netmgr(void **state ISC_ATTR_UNUSED) {
 	REQUIRE(loopmgr != NULL);
 
-	isc_netmgr_destroy(&netmgr);
+	isc_nm_detach(&netmgr);
 
 	return 0;
 }