dns: rework pending request-queue in NMDnsSystemdResolved

We had two separate queues, one for "SetLinkDNS" and one for
"SetLinkDomains". Merge them into one, and track the operation
as part of the new RequestItem structure.

A visible change to before is that we now would make all requests
per-interface first. Prevously, we would first make all SetLinkDNS
requests (for all interfaces) and then all SetLinkDomains requests.
It feels more correct to order the requests this way, not by
type.

The reason to merge is, that we will next get another operation
and in the current scheme we would need 3 GQueue instances.

While at it, refactor the code to use CList. We now anyway would
need a new struct to track the operation, requiring to allocate
and free it. Previously, we would only track the GVariant argument
as data of the GQueue.

1 files changed, 56 insertions, 26 deletions

diff --git a/src/dns/nm-dns-systemd-resolved.c b/src/dns/nm-dns-systemd-resolved.c
index f37a1e7497..73a0977cc9 100644
--- a/src/dns/nm-dns-systemd-resolved.c
+++ b/src/dns/nm-dns-systemd-resolved.c
@@ -53,6 +53,12 @@ typedef struct {
 	CList configs_lst_head;
 } InterfaceConfig;
 
+typedef struct {
+	CList request_queue_lst;
+	const char *operation;
+	GVariant *argument;
+} RequestItem;
+
 /*****************************************************************************/
 
 typedef struct {
@@ -60,8 +66,7 @@ typedef struct {
 	GCancellable *init_cancellable;
 	GCancellable *update_cancellable;
 	GCancellable *mdns_cancellable;
-	GQueue dns_updates;
-	GQueue domain_updates;
+	CList request_queue_lst_head;
 } NMDnsSystemdResolvedPrivate;
 
 struct _NMDnsSystemdResolved {
@@ -85,6 +90,29 @@ G_DEFINE_TYPE (NMDnsSystemdResolved, nm_dns_systemd_resolved, NM_TYPE_DNS_PLUGIN
 /*****************************************************************************/
 
 static void
+_request_item_free (RequestItem *request_item)
+{
+	c_list_unlink_stale (&request_item->request_queue_lst);
+	g_variant_unref (request_item->argument);
+	g_slice_free (RequestItem, request_item);
+}
+
+static void
+_request_item_append (CList *request_queue_lst_head,
+                      const char *operation,
+                      GVariant *argument)
+{
+	RequestItem *request_item;
+
+	request_item = g_slice_new (RequestItem);
+	request_item->operation = operation;
+	request_item->argument = g_variant_ref_sink (argument);
+	c_list_link_tail (request_queue_lst_head, &request_item->request_queue_lst);
+}
+
+/*****************************************************************************/
+
+static void
 _interface_config_free (InterfaceConfig *config)
 {
 	nm_c_list_elem_free_all (&config->configs_lst_head, NULL);
@@ -185,13 +213,13 @@ static void
 free_pending_updates (NMDnsSystemdResolved *self)
 {
 	NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
-	GVariant *v;
-
-	while ((v = g_queue_pop_head (&priv->dns_updates)) != NULL)
-		g_variant_unref (v);
+	RequestItem *request_item, *request_item_safe;
 
-	while ((v = g_queue_pop_head (&priv->domain_updates)) != NULL)
-		g_variant_unref (v);
+	c_list_for_each_entry_safe (request_item,
+	                            request_item_safe,
+	                            &priv->request_queue_lst_head,
+	                            request_queue_lst)
+		_request_item_free (request_item);
 }
 
 static void
@@ -215,17 +243,19 @@ prepare_one_interface (NMDnsSystemdResolved *self, InterfaceConfig *ic)
 	g_variant_builder_close (&dns);
 	g_variant_builder_close (&domains);
 
-	g_queue_push_tail (&priv->dns_updates,
-	                   g_variant_ref_sink (g_variant_builder_end (&dns)));
-	g_queue_push_tail (&priv->domain_updates,
-	                   g_variant_ref_sink (g_variant_builder_end (&domains)));
+	_request_item_append (&priv->request_queue_lst_head,
+	                      "SetLinkDNS",
+	                      g_variant_builder_end (&dns));
+	_request_item_append (&priv->request_queue_lst_head,
+	                      "SetLinkDomains",
+	                      g_variant_builder_end (&domains));
 }
 
 static void
 send_updates (NMDnsSystemdResolved *self)
 {
 	NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
-	GVariant *v;
+	RequestItem *request_item, *request_item_safe;
 
 	nm_clear_g_cancellable (&priv->update_cancellable);
 
@@ -234,18 +264,19 @@ send_updates (NMDnsSystemdResolved *self)
 
 	priv->update_cancellable = g_cancellable_new ();
 
-	while ((v = g_queue_pop_head (&priv->dns_updates)) != NULL) {
-		g_dbus_proxy_call (priv->resolve, "SetLinkDNS", v,
-		                   G_DBUS_CALL_FLAGS_NONE,
-		                   -1, priv->update_cancellable, call_done, self);
-		g_variant_unref (v);
-	}
-
-	while ((v = g_queue_pop_head (&priv->domain_updates)) != NULL) {
-		g_dbus_proxy_call (priv->resolve, "SetLinkDomains", v,
+	c_list_for_each_entry_safe (request_item,
+	                            request_item_safe,
+	                            &priv->request_queue_lst_head,
+	                            request_queue_lst) {
+		g_dbus_proxy_call (priv->resolve,
+		                   request_item->operation,
+		                   request_item->argument,
 		                   G_DBUS_CALL_FLAGS_NONE,
-		                   -1, priv->update_cancellable, call_done, self);
-		g_variant_unref (v);
+		                   -1,
+		                   priv->update_cancellable,
+		                   call_done,
+		                   self);
+		_request_item_free (request_item);
 	}
 }
 
@@ -403,8 +434,7 @@ nm_dns_systemd_resolved_init (NMDnsSystemdResolved *self)
 	NMBusManager *dbus_mgr;
 	GDBusConnection *connection;
 
-	g_queue_init (&priv->dns_updates);
-	g_queue_init (&priv->domain_updates);
+	c_list_init (&priv->request_queue_lst_head);
 
 	dbus_mgr = nm_bus_manager_get ();
 	g_return_if_fail (dbus_mgr);