Add a lifecycle manager to xfconfd

Copied from Tumbler, with some adjustments.

Closes #28, see !19 for more details.

6 files changed, 336 insertions, 36 deletions

diff --git a/xfconfd/Makefile.am b/xfconfd/Makefile.am
index d7fdfcb..248efb6 100644
--- a/xfconfd/Makefile.am
+++ b/xfconfd/Makefile.am
@@ -26,6 +26,8 @@ xfconfd_SOURCES = \
 	xfconf-backend.h \
 	xfconf-daemon.c \
 	xfconf-daemon.h \
+	xfconf-lifecycle-manager.c \
+	xfconf-lifecycle-manager.h \
 	xfconf-locking-utils.c \
 	xfconf-locking-utils.h \
 	$(xfconf_backend_sources) \
diff --git a/xfconfd/main.c b/xfconfd/main.c
index 1965210..c2b3830 100644
--- a/xfconfd/main.c
+++ b/xfconfd/main.c
@@ -136,6 +136,7 @@ main(int argc,
 {
     GMainLoop *mloop;
     XfconfDaemon *xfconfd;
+    XfconfLifecycleManager *manager;
     GError *error = NULL;
     struct sigaction act = {0};
     GIOChannel *signal_io;
@@ -220,15 +221,21 @@ main(int argc,
         backends = g_new0(gchar *, 2);
         backends[0] = g_strdup(DEFAULT_BACKEND);
     }
-    
-    xfconfd = xfconf_daemon_new_unique(backends, &error);
+
+    manager = xfconf_lifecycle_manager_new ();
+    xfconfd = xfconf_daemon_new_unique (backends, manager, &error);
     if(!xfconfd) {
         g_critical("Xfconfd failed to start: %s\n", error->message);
+        g_object_unref (manager);
         g_error_free(error);
         return EXIT_FAILURE;
     }
     g_strfreev(backends);
-    
+
+    /* quit the main loop when the xfconf daemon asks us to shutdown */
+    g_signal_connect_swapped (manager, "shutdown", G_CALLBACK (g_main_loop_quit), mloop);
+    xfconf_lifecycle_manager_start (manager);
+
     /* acquire name */
     is_test_mode = g_getenv ("XFCONF_RUN_IN_TEST_MODE");
     g_bus_own_name (G_BUS_TYPE_SESSION,
@@ -256,7 +263,8 @@ main(int argc,
     
     g_main_loop_run(mloop);
     
-    g_object_unref(G_OBJECT(xfconfd));
+    g_object_unref (xfconfd);
+    g_object_unref (manager);
 
     xfconf_backend_factory_cleanup();
     
diff --git a/xfconfd/xfconf-daemon.c b/xfconfd/xfconf-daemon.c
index fbe5da3..314b76c 100644
--- a/xfconfd/xfconf-daemon.c
+++ b/xfconfd/xfconf-daemon.c
@@ -175,7 +175,7 @@ xfconf_set_property(XfconfExported *skeleton,
         if(error) {
             g_dbus_method_invocation_return_gerror(invocation, error);
             g_error_free(error);
-            return FALSE;
+            return G_DBUS_METHOD_INVOCATION_UNHANDLED;
         }
     }
     
@@ -192,7 +192,7 @@ xfconf_set_property(XfconfExported *skeleton,
 
     g_value_unset (value);
     g_free (value);
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 
@@ -225,13 +225,13 @@ xfconf_get_property(XfconfExported *skeleton,
                 g_error_free(error);
             }
             g_value_unset(&value);
-            return TRUE;
+            return G_DBUS_METHOD_INVOCATION_UNHANDLED;
         } else if(l->next)
             g_clear_error(&error);
     }
     g_dbus_method_invocation_return_gerror(invocation, error);
     g_error_free(error);
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static gboolean
@@ -248,7 +248,7 @@ xfconf_get_all_properties(XfconfExported *skeleton,
     properties = g_hash_table_new_full(g_str_hash, g_str_equal,
                                         (GDestroyNotify)g_free,
                                         (GDestroyNotify)_xfconf_gvalue_free);
-    /* get all properties from all backends.  if they all fail, return FALSE */
+    /* get all properties from all backends */
     for(l = xfconfd->backends; l; l = l->next) {
         if(xfconf_backend_get_all(l->data, channel, property_base,
                                   properties, &error))
@@ -268,7 +268,7 @@ xfconf_get_all_properties(XfconfExported *skeleton,
     if(error)
         g_error_free(error);
     g_hash_table_destroy(properties);
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static gboolean
@@ -282,8 +282,7 @@ xfconf_property_exists(XfconfExported *skeleton,
     gboolean succeed = FALSE;
     GList *l;
     GError *error = NULL;
-    /* if at least one backend returns TRUE (regardles if |*exists| gets set
-     * to TRUE or FALSE), we'll return TRUE from this function */
+
     for(l = xfconfd->backends; !exists && l; l = l->next) {
         if(xfconf_backend_exists(l->data, channel, property, &exists, &error))
             succeed = TRUE;
@@ -297,7 +296,7 @@ xfconf_property_exists(XfconfExported *skeleton,
         g_dbus_method_invocation_return_gerror(invocation, error);
         g_error_free(error);
     }
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static gboolean
@@ -330,7 +329,7 @@ xfconf_reset_property(XfconfExported *skeleton,
     if(error)
         g_error_free(error);
 
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static gboolean
@@ -370,7 +369,7 @@ xfconf_list_channels(XfconfExported *skeleton,
     if(error)
         g_error_free(error);
 
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static gboolean xfconf_is_property_locked(XfconfExported *skeleton,
@@ -399,7 +398,7 @@ static gboolean xfconf_is_property_locked(XfconfExported *skeleton,
     if(error)
         g_error_free(error);
 
-    return TRUE;
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
 }
 
 static void
@@ -491,8 +490,39 @@ xfconf_daemon_load_config(XfconfDaemon *xfconfd,
 }
 
 
+#define XFCONF_DAEMON_CONNECT(signal_name, signal_handler) \
+    G_STMT_START{ \
+        g_signal_connect_swapped (xfconfd, signal_name, \
+                                  G_CALLBACK (xfconf_lifecycle_manager_increment_use_count), \
+                                  manager); \
+        g_signal_connect (xfconfd, signal_name, signal_handler, xfconfd); \
+        g_signal_connect_swapped (xfconfd, signal_name, \
+                                  G_CALLBACK (xfconf_lifecycle_manager_keep_alive), manager); \
+        g_signal_connect_swapped (xfconfd, signal_name, \
+                                  G_CALLBACK (xfconf_lifecycle_manager_decrement_use_count), \
+                                  manager); \
+    }G_STMT_END
+
+typedef struct
+{
+    gchar *name;
+    GCallback handler;
+} XfconfExportedSignal;
+
+static const XfconfExportedSignal xfconf_exported_signals[] =
+{
+    { "handle-get-all-properties", G_CALLBACK (xfconf_get_all_properties) },
+    { "handle-get-property", G_CALLBACK (xfconf_get_property) },
+    { "handle-is-property-locked", G_CALLBACK (xfconf_is_property_locked) },
+    { "handle-list-channels", G_CALLBACK (xfconf_list_channels) },
+    { "handle-property-exists", G_CALLBACK (xfconf_property_exists) },
+    { "handle-reset-property", G_CALLBACK (xfconf_reset_property) },
+    { "handle-set-property", G_CALLBACK (xfconf_set_property) },
+};
+
 XfconfDaemon *
 xfconf_daemon_new_unique(gchar * const *backend_ids,
+                         XfconfLifecycleManager *manager,
                          GError **error)
 {
     XfconfDaemon *xfconfd;
@@ -508,26 +538,9 @@ xfconf_daemon_new_unique(gchar * const *backend_ids,
         return NULL;
     }
 
-    g_signal_connect (xfconfd, "handle-get-all-properties",
-                      G_CALLBACK(xfconf_get_all_properties), xfconfd);
-    
-    g_signal_connect (xfconfd, "handle-get-property",
-                      G_CALLBACK(xfconf_get_property), xfconfd);
-
-    g_signal_connect (xfconfd, "handle-is-property-locked",
-                      G_CALLBACK(xfconf_is_property_locked), xfconfd);
-    
-    g_signal_connect (xfconfd, "handle-list-channels",
-                      G_CALLBACK(xfconf_list_channels), xfconfd);
+    for (guint n = 0; n < G_N_ELEMENTS (xfconf_exported_signals); n++)
+        XFCONF_DAEMON_CONNECT (xfconf_exported_signals[n].name,
+                               xfconf_exported_signals[n].handler);
 
-    g_signal_connect (xfconfd, "handle-property-exists",
-                      G_CALLBACK(xfconf_property_exists), xfconfd);
-    
-    g_signal_connect (xfconfd, "handle-reset-property",
-                      G_CALLBACK(xfconf_reset_property), xfconfd);
-    
-    g_signal_connect (xfconfd, "handle-set-property",
-                      G_CALLBACK(xfconf_set_property), xfconfd);
-    
     return xfconfd;
 }
diff --git a/xfconfd/xfconf-daemon.h b/xfconfd/xfconf-daemon.h
index aaddb2a..1735ee7 100644
--- a/xfconfd/xfconf-daemon.h
+++ b/xfconfd/xfconf-daemon.h
@@ -21,6 +21,7 @@
 #define __XFCONF_DAEMON_H__
 
 #include <glib-object.h>
+#include "xfconf-lifecycle-manager.h"
 #include "xfconf/xfconf-errors.h"
 
 #define XFCONF_TYPE_DAEMON             (xfconf_daemon_get_type())
@@ -37,6 +38,7 @@ typedef struct _XfconfDaemon         XfconfDaemon;
 GType xfconf_daemon_get_type(void) G_GNUC_CONST;
 
 XfconfDaemon *xfconf_daemon_new_unique(gchar * const *backend_ids,
+                                       XfconfLifecycleManager *manager,
                                        GError **error);
 
 G_END_DECLS
diff --git a/xfconfd/xfconf-lifecycle-manager.c b/xfconfd/xfconf-lifecycle-manager.c
new file mode 100644
index 0000000..794f3ad
--- /dev/null
+++ b/xfconfd/xfconf-lifecycle-manager.c
@@ -0,0 +1,224 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License ONLY.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gio/gio.h>
+
+#include <xfconf-lifecycle-manager.h>
+
+
+
+#define SHUTDOWN_TIMEOUT_SECONDS 300
+
+
+
+enum
+{
+    SIGNAL_SHUTDOWN,
+    N_SIGNALS,
+};
+
+
+
+static void xfconf_lifecycle_manager_finalize (GObject *object);
+
+
+
+struct _XfconfLifecycleManagerPrivate
+{
+    GMutex lock;
+
+    guint timeout_id;
+    guint use_count;
+    gboolean shutdown_emitted;
+};
+
+
+
+static guint lifecycle_manager_signals[N_SIGNALS];
+
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (XfconfLifecycleManager, xfconf_lifecycle_manager, G_TYPE_OBJECT)
+
+
+
+static void
+xfconf_lifecycle_manager_class_init (XfconfLifecycleManagerClass *klass)
+{
+    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+    gobject_class->finalize = xfconf_lifecycle_manager_finalize;
+
+    lifecycle_manager_signals[SIGNAL_SHUTDOWN] =
+        g_signal_new ("shutdown", XFCONF_TYPE_LIFECYCLE_MANAGER, G_SIGNAL_RUN_LAST, 0,
+                      NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
+}
+
+
+
+static void
+xfconf_lifecycle_manager_init (XfconfLifecycleManager *manager)
+{
+    manager->priv = xfconf_lifecycle_manager_get_instance_private (manager);
+    g_mutex_init (&manager->priv->lock);
+    manager->priv->timeout_id = 0;
+    manager->priv->use_count = 0;
+    manager->priv->shutdown_emitted = FALSE;
+}
+
+
+
+static void
+xfconf_lifecycle_manager_finalize (GObject *object)
+{
+    XfconfLifecycleManager *manager = XFCONF_LIFECYCLE_MANAGER (object);
+
+    g_mutex_clear (&manager->priv->lock);
+
+    G_OBJECT_CLASS (xfconf_lifecycle_manager_parent_class)->finalize (object);
+}
+
+
+
+static gboolean
+xfconf_lifecycle_manager_timeout (gpointer user_data)
+{
+    XfconfLifecycleManager *manager = user_data;
+
+    g_mutex_lock (&manager->priv->lock);
+
+    /* reschedule the timeout if the daemon is currently in use */
+    if (manager->priv->use_count > 0)
+    {
+        g_mutex_unlock (&manager->priv->lock);
+        return TRUE;
+    }
+
+    /* reset the timeout id */
+    manager->priv->timeout_id = 0;
+
+    /* emit the shutdown signal */
+    g_signal_emit (manager, lifecycle_manager_signals[SIGNAL_SHUTDOWN], 0);
+
+    /* set the shutdown emitted flag to force other threads not to reschedule
+     * the timeout */
+    manager->priv->shutdown_emitted = TRUE;
+
+    g_mutex_unlock (&manager->priv->lock);
+
+    return FALSE;
+}
+
+
+
+XfconfLifecycleManager *
+xfconf_lifecycle_manager_new (void)
+{
+    return g_object_new (XFCONF_TYPE_LIFECYCLE_MANAGER, NULL);
+}
+
+
+
+void
+xfconf_lifecycle_manager_start (XfconfLifecycleManager *manager)
+{
+    g_return_if_fail (XFCONF_IS_LIFECYCLE_MANAGER (manager));
+
+    g_mutex_lock (&manager->priv->lock);
+
+    /* ignore if there already is a timeout scheduled */
+    if (manager->priv->timeout_id != 0)
+    {
+        g_mutex_unlock (&manager->priv->lock);
+        return;
+    }
+
+    manager->priv->timeout_id =
+        g_timeout_add_seconds (SHUTDOWN_TIMEOUT_SECONDS,
+                               xfconf_lifecycle_manager_timeout,
+                               manager);
+
+    g_mutex_unlock (&manager->priv->lock);
+}
+
+
+
+gboolean
+xfconf_lifecycle_manager_keep_alive (XfconfLifecycleManager *manager)
+{
+    g_return_val_if_fail (XFCONF_IS_LIFECYCLE_MANAGER (manager), G_DBUS_METHOD_INVOCATION_UNHANDLED);
+
+    g_mutex_lock (&manager->priv->lock);
+
+    /* if the shutdown signal has been emitted, there's nothing we can do to prevent
+     * a shutdown anymore */
+    if (manager->priv->shutdown_emitted)
+    {
+        g_mutex_unlock (&manager->priv->lock);
+        return G_DBUS_METHOD_INVOCATION_UNHANDLED;
+    }
+
+    /* drop existing timeout, if any */
+    if (manager->priv->timeout_id != 0)
+        g_source_remove (manager->priv->timeout_id);
+
+    /* reschedule the shutdown timeout */
+    manager->priv->timeout_id =
+        g_timeout_add_seconds (SHUTDOWN_TIMEOUT_SECONDS,
+                               xfconf_lifecycle_manager_timeout,
+                               manager);
+
+    g_mutex_unlock (&manager->priv->lock);
+
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
+}
+
+
+
+gboolean
+xfconf_lifecycle_manager_increment_use_count (XfconfLifecycleManager *manager)
+{
+    g_return_val_if_fail (XFCONF_IS_LIFECYCLE_MANAGER (manager), G_DBUS_METHOD_INVOCATION_UNHANDLED);
+
+    g_mutex_lock (&manager->priv->lock);
+
+    manager->priv->use_count++;
+
+    g_mutex_unlock (&manager->priv->lock);
+
+    return G_DBUS_METHOD_INVOCATION_UNHANDLED;
+}
+
+
+
+gboolean
+xfconf_lifecycle_manager_decrement_use_count (XfconfLifecycleManager *manager)
+{
+    g_return_val_if_fail (XFCONF_IS_LIFECYCLE_MANAGER (manager), G_DBUS_METHOD_INVOCATION_HANDLED);
+
+    g_mutex_lock (&manager->priv->lock);
+
+    /* decrement the use count, make sure not to drop below zero */
+    if (manager->priv->use_count > 0)
+        manager->priv->use_count--;
+
+    g_mutex_unlock (&manager->priv->lock);
+
+    return G_DBUS_METHOD_INVOCATION_HANDLED;
+}
diff --git a/xfconfd/xfconf-lifecycle-manager.h b/xfconfd/xfconf-lifecycle-manager.h
new file mode 100644
index 0000000..5c4b6ad
--- /dev/null
+++ b/xfconfd/xfconf-lifecycle-manager.h
@@ -0,0 +1,51 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License ONLY.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __XFCONF_LIFECYCLE_MANAGER_H__
+#define __XFCONF_LIFECYCLE_MANAGER_H__
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#if ! GLIB_CHECK_VERSION (2, 68, 0)
+#define G_DBUS_METHOD_INVOCATION_HANDLED TRUE
+#define G_DBUS_METHOD_INVOCATION_UNHANDLED FALSE
+#endif
+
+#define XFCONF_TYPE_LIFECYCLE_MANAGER xfconf_lifecycle_manager_get_type ()
+G_DECLARE_FINAL_TYPE (XfconfLifecycleManager, xfconf_lifecycle_manager, XFCONF, LIFECYCLE_MANAGER, GObject)
+
+typedef struct _XfconfLifecycleManagerPrivate XfconfLifecycleManagerPrivate;
+
+struct _XfconfLifecycleManager
+{
+    GObject parent;
+    XfconfLifecycleManagerPrivate *priv;
+};
+
+XfconfLifecycleManager* xfconf_lifecycle_manager_new (void) G_GNUC_MALLOC G_GNUC_WARN_UNUSED_RESULT;
+
+void xfconf_lifecycle_manager_start (XfconfLifecycleManager *manager);
+
+gboolean xfconf_lifecycle_manager_keep_alive (XfconfLifecycleManager *manager);
+
+gboolean xfconf_lifecycle_manager_increment_use_count (XfconfLifecycleManager *manager);
+
+gboolean xfconf_lifecycle_manager_decrement_use_count (XfconfLifecycleManager *manager);
+
+G_END_DECLS
+
+#endif /* !__XFCONF_LIFECYCLE_MANAGER_H__ */