agent: Implement Agent API message queueing

Add functions for queuing Agent API messages and sending the
first one when there is no message processed by the agent.

Handle D-Bus pending call replies and simplify the D-Bus reply
processing by handing the message to the callback function.

diff --git a/src/agent.c b/src/agent.c
index 52638ac..afcf2cb 100644 (file)
--- a/src/agent.c
+++ b/src/agent.c
@@ -36,6 +36,20 @@ static guint agent_watch = 0;
 static gchar *agent_path = NULL;
 static gchar *agent_sender = NULL;
 
+typedef void (*agent_queue_cb)(DBusMessage *reply, void *user_data);
+
+struct agent_data {
+       struct connman_service *service;
+       DBusMessage *msg;
+       DBusPendingCall *call;
+       int timeout;
+       agent_queue_cb callback;
+       void *user_data;
+};
+
+static GList *agent_queue = NULL;
+static struct agent_data *agent_request = NULL;
+
 static void agent_free(void)
 {
        agent_watch = 0;
@@ -85,6 +99,106 @@ int __connman_agent_unregister(const char *sender, const char *path)
        return 0;
 }
 
+static void agent_data_free(struct agent_data *data)
+{
+       if (data == NULL)
+               return;
+       if (data->service != NULL)
+               connman_service_unref(data->service);
+       if (data->msg != NULL)
+               dbus_message_unref(data->msg);
+       if (data->call != NULL)
+               dbus_pending_call_cancel(data->call);
+
+       g_free(data);
+}
+
+static void agent_receive_message(DBusPendingCall *call, void *user_data);
+
+static int agent_send_next_request(void)
+{
+       if (agent_request != NULL)
+               return -EBUSY;
+
+       if (agent_queue == NULL)
+               return 0;
+
+       agent_request = agent_queue->data;
+       agent_queue = g_list_remove(agent_queue, agent_request);
+
+       if (dbus_connection_send_with_reply(connection, agent_request->msg,
+                                       &agent_request->call,
+                                       agent_request->timeout)
+                       == FALSE)
+               goto fail;
+
+       if (agent_request->call == NULL)
+               goto fail;
+
+       if (dbus_pending_call_set_notify(agent_request->call,
+                                       agent_receive_message, agent_request,
+                                       NULL) == FALSE)
+               goto fail;
+
+       dbus_message_unref(agent_request->msg);
+       agent_request->msg = NULL;
+       return 0;
+
+fail:
+       agent_data_free(agent_request);
+       agent_request = NULL;
+       return -ESRCH;
+}
+
+static void agent_receive_message(DBusPendingCall *call, void *user_data)
+{
+       struct agent_data *queue_data = user_data;
+       DBusMessage *reply;
+
+       DBG("waiting for %p received %p", agent_request, queue_data);
+
+       if (agent_request != queue_data) {
+               connman_error("Agent callback expected %p got %p",
+                               agent_request, queue_data);
+               return;
+       }
+
+       reply = dbus_pending_call_steal_reply(call);
+       dbus_pending_call_unref(call);
+       queue_data->call = NULL;
+
+       queue_data->callback(reply, queue_data->user_data);
+       dbus_message_unref(reply);
+
+       agent_data_free(queue_data);
+       agent_request = NULL;
+
+       agent_send_next_request();
+}
+
+static int agent_queue_message(struct connman_service *service,
+               DBusMessage *msg, int timeout,
+               DBusPendingCallNotifyFunction callback, void *user_data)
+{
+       struct agent_data *queue_data;
+
+       if (service == NULL || callback == NULL)
+               return -EBADMSG;
+
+       queue_data = g_new0(struct agent_data, 1);
+       if (queue_data == NULL)
+               return -ENOMEM;
+
+       queue_data->service = connman_service_ref(service);
+       queue_data->msg = dbus_message_ref(msg);
+       queue_data->timeout = timeout;
+       queue_data->callback = callback;
+       queue_data->user_data = user_data;
+       agent_queue = g_list_append(agent_queue, queue_data);
+
+       return agent_send_next_request();
+}
+
 static connman_bool_t check_reply_has_dict(DBusMessage *reply)
 {
        const char *signature = DBUS_TYPE_ARRAY_AS_STRING