Change how config file errors are reportedHEADmaster

Signed-off-by: David Zeuthen <davidz@redhat.com>

14 files changed, 875 insertions, 375 deletions

diff --git a/doc/stc-docs.xml b/doc/stc-docs.xml
index cd6addb..d023a6a 100644
--- a/doc/stc-docs.xml
+++ b/doc/stc-docs.xml
@@ -37,6 +37,7 @@
     <xi:include href="xml/stcerror.xml"/>
     <xi:include href="xml/stcitem.xml"/>
     <xi:include href="xml/stcmonitor.xml"/>
+    <xi:include href="xml/stcconfigerror.xml"/>
     <xi:include href="xml/stcoperation.xml"/>
   </part>
 
diff --git a/doc/stc-sections.txt b/doc/stc-sections.txt
index 685f97f..5b853a7 100644
--- a/doc/stc-sections.txt
+++ b/doc/stc-sections.txt
@@ -2,10 +2,10 @@
 <FILE>stcmonitor</FILE>
 <TITLE>StcMonitor</TITLE>
 StcMonitor
-StcErrorHandlerFunc
 stc_monitor_new
 stc_monitor_get_items
 stc_monitor_get_item_by_id
+stc_monitor_get_config_errors
 <SUBSECTION Standard>
 STC_TYPE_MONITOR
 STC_MONITOR
@@ -77,3 +77,24 @@ stc_error_quark
 stc_error_get_type
 STC_TYPE_ERROR
 </SECTION>
+
+<SECTION>
+<FILE>stcconfigerror</FILE>
+<TITLE>StcConfigError</TITLE>
+StcConfigError
+StcConfigErrorSeverity
+stc_config_error_new
+stc_config_error_ref
+stc_config_error_unref
+stc_config_error_compare
+stc_config_error_get_item_id
+stc_config_error_get_filename
+stc_config_error_get_line_number
+stc_config_error_get_severity
+stc_config_error_get_message
+<SUBSECTION Private>
+stc_config_error_get_type
+STC_TYPE_CONFIG_ERROR
+stc_config_error_severity_get_type
+STC_TYPE_CONFIG_ERROR_SEVERITY
+</SECTION>
diff --git a/doc/stc.types b/doc/stc.types
index 15a8430..c15e6ed 100644
--- a/doc/stc.types
+++ b/doc/stc.types
@@ -1,3 +1,4 @@
 stc_item_get_type
 stc_monitor_get_type
 stc_operation_get_type
+stc_config_error_get_type
diff --git a/stc/Makefile.am b/stc/Makefile.am
index 1ee3072..41addff 100644
--- a/stc/Makefile.am
+++ b/stc/Makefile.am
@@ -46,6 +46,7 @@ libstc_1includedir=$(includedir)/stc-1/stc
 
 libstc_1include_HEADERS=								\
 	stc.h										\
+	stcconfigerror.h								\
 	stcenums.h									\
 	stcenumtypes.h									\
 	stcerror.h									\
@@ -57,6 +58,7 @@ libstc_1include_HEADERS=								\
 libstc_1_la_SOURCES =									\
 	$(BUILT_SOURCES)								\
 	stcenums.h									\
+	stcconfigerror.h			stcconfigerror.c			\
 	stcerror.h				stcerror.c				\
 	stcitem.h				stcitem.c				\
 	stcmonitor.h				stcmonitor.c				\
diff --git a/stc/stc.c b/stc/stc.c
index 2d3b093..61ce14e 100644
--- a/stc/stc.c
+++ b/stc/stc.c
@@ -191,30 +191,57 @@ _color_run_pager (void)
 /* ---------------------------------------------------------------------------------------------------- */
 
 static void
-error_handler (StcMonitor   *monitor,
-               const gchar  *filename,
-               gint          line_no,
-               GError       *error,
-               gpointer      user_data)
+print_config_error (StcMonitor     *monitor,
+                    StcConfigError *config_error)
 {
   GString *str;
+  const gchar *item_id;
+  const gchar *filename;
+  gint line_number;
+  StcConfigErrorSeverity severity;
+  const gchar *message;
+
+  item_id = stc_config_error_get_item_id (config_error);
+  filename = stc_config_error_get_filename (config_error);
+  line_number = stc_config_error_get_line_number (config_error);
+  severity = stc_config_error_get_severity (config_error);
+  message = stc_config_error_get_message (config_error);
 
   str = g_string_new (NULL);
   g_string_append_printf (str, "%s%s", _color_get (_COLOR_BOLD_ON), _color_get (_COLOR_FG_YELLOW));
   if (filename != NULL)
     {
-      if (line_no >= 0)
-        g_string_append_printf (str, "%s:%d: ", filename, line_no);
+      if (line_number >= 0)
+        g_string_append_printf (str, "%s:%d: ", filename, line_number);
       else
         g_string_append_printf (str, "%s: ", filename);
     }
   g_string_append_printf (str, "%s", _color_get (_COLOR_RESET));
-  g_string_append_printf (str, "%s%s", _color_get (_COLOR_BOLD_ON), _color_get (_COLOR_FG_RED));
-  g_string_append_printf (str, "%s", error->message);
-  g_string_append_printf (str, "%s", _color_get (_COLOR_RESET));
-  g_string_append_printf (str, "%s", _color_get (_COLOR_FG_BLUE));
-  g_string_append_printf (str, " (%s, %d)", g_quark_to_string (error->domain), error->code);
-  g_string_append_printf (str, "%s", _color_get (_COLOR_RESET));
+  if (item_id != NULL)
+    {
+      g_string_append_printf (str, "%s%s%s: %s",
+                              _color_get (_COLOR_BOLD_ON),
+                              _color_get (_COLOR_FG_BLUE),
+                              item_id,
+                              _color_get (_COLOR_RESET));
+    }
+  switch (severity)
+    {
+    case STC_CONFIG_ERROR_SEVERITY_WARNING:
+      g_string_append_printf (str, "%s%s[WARNING]: %s",
+                              _color_get (_COLOR_BOLD_ON),
+                              _color_get (_COLOR_FG_YELLOW),
+                              _color_get (_COLOR_RESET));
+      break;
+
+    case STC_CONFIG_ERROR_SEVERITY_ERROR:
+      g_string_append_printf (str, "%s%s[ERROR]: %s",
+                              _color_get (_COLOR_BOLD_ON),
+                              _color_get (_COLOR_FG_RED),
+                              _color_get (_COLOR_RESET));
+      break;
+    }
+  g_string_append_printf (str, "%s", message);
 
   if (_color_stdin_is_tty)
     g_print ("%s\n", str->str);
@@ -223,6 +250,22 @@ error_handler (StcMonitor   *monitor,
   g_string_free (str, TRUE);
 }
 
+static void
+print_all_config_errors (StcMonitor *monitor)
+{
+  GList *config_errors;
+  GList *l;
+
+  config_errors = stc_monitor_get_config_errors (monitor);
+  for (l = config_errors; l != NULL; l = l->next)
+    {
+      StcConfigError *config_error = l->data;
+      print_config_error (monitor, config_error);
+    }
+  g_list_foreach (config_errors, (GFunc) stc_config_error_unref, NULL);
+  g_list_free (config_errors);
+}
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 static const GOptionEntry command_list_entries[] =
@@ -274,7 +317,8 @@ handle_command_list (gint        *argc,
 
   _color_run_pager ();
 
-  monitor = stc_monitor_new (error_handler, NULL);
+  monitor = stc_monitor_new ();
+  print_all_config_errors (monitor);
 
   items = stc_monitor_get_items (monitor);
 
@@ -877,7 +921,8 @@ handle_command_start_stop (gint        *argc,
       g_print ("--allow-degraded \n");
     }
 
-  monitor = stc_monitor_new (error_handler, NULL);
+  monitor = stc_monitor_new ();
+  print_all_config_errors (monitor);
 
   if (complete_ids)
     {
diff --git a/stc/stc.h b/stc/stc.h
index fa606ab..1ce5b9a 100644
--- a/stc/stc.h
+++ b/stc/stc.h
@@ -34,6 +34,7 @@
 #include <stc/stcerror.h>
 #include <stc/stcitem.h>
 #include <stc/stcmonitor.h>
+#include <stc/stcconfigerror.h>
 #include <stc/stcoperation.h>
 #undef __STC_INSIDE_STC_H__
 
diff --git a/stc/stcconfigerror.c b/stc/stcconfigerror.c
new file mode 100644
index 0000000..a1774b7
--- /dev/null
+++ b/stc/stcconfigerror.c
@@ -0,0 +1,229 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2007-2010 David Zeuthen <zeuthen@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: David Zeuthen <zeuthen@gmail.com>
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include "stcconfigerror.h"
+
+/**
+ * SECTION:stcconfigerror
+ * @title: StcConfigError
+ * @short_description: Details about configuration file errors
+ *
+ * Boxed type used for reporting errors in configuration files.
+ */
+
+/**
+ * StcConfigError:
+ *
+ * The #StcConfigError structure contains only private data and should
+ * only be accessed using the provided API.
+ */
+struct _StcConfigError
+{
+  volatile gint           ref_count;
+  gchar                  *item_id;
+  gchar                  *filename;
+  gint                    line_number;
+  StcConfigErrorSeverity  severity;
+  gchar                  *message;
+};
+
+G_DEFINE_BOXED_TYPE (StcConfigError, stc_config_error, stc_config_error_ref, stc_config_error_unref);
+
+/**
+ * stc_config_error_ref:
+ * @error: A #StcConfigError.
+ *
+ * Increases the reference count on @error.
+ *
+ * Returns: The same @error.
+ */
+StcConfigError *
+stc_config_error_ref (StcConfigError *error)
+{
+  g_atomic_int_inc (&error->ref_count);
+  return error;
+}
+
+/**
+ * stc_config_error_unref:
+ * @error: A #StcConfigError.
+ *
+ * Decreases the reference count on @error. When the reference count
+ * drops to zero, all resources used are freed.
+ */
+void
+stc_config_error_unref (StcConfigError *error)
+{
+  if (g_atomic_int_dec_and_test (&error->ref_count))
+    {
+      g_free (error->item_id);
+      g_free (error->filename);
+      g_free (error->message);
+      g_slice_free (StcConfigError, error);
+    }
+}
+
+/**
+ * stc_config_error_new:
+ * @item_id: The item the error is about or %NULL if not about a specific item.
+ * @filename: The filename where the error is.
+ * @line_number: The line number where the error is or -1 if unknown.
+ * @severity: The severity of the error.
+ * @message: A human-readable message describing the error.
+ *
+ * Create a new #StcConfigError.
+ *
+ * Returns: A newly allocated #StcConfigError structure. Free with stc_config_error_unref().
+ */
+StcConfigError *
+stc_config_error_new (const gchar            *item_id,
+                      const gchar            *filename,
+                      gint                    line_number,
+                      StcConfigErrorSeverity  severity,
+                      const gchar            *message)
+{
+  StcConfigError *error;
+  error = g_slice_new0 (StcConfigError);
+  error->ref_count = 1;
+  error->item_id = g_strdup (item_id);
+  error->filename = g_strdup (filename);
+  error->line_number = line_number;
+  error->severity = severity;
+  error->message = g_strdup (message);
+  return error;
+}
+
+/**
+ * stc_config_error_get_item_id:
+ * @error: A #StcConfigError.
+ *
+ * Gets the item the error is for, if any.
+ *
+ * Returns: A string owned by @error or %NULL. Do not free.
+ */
+const gchar *
+stc_config_error_get_item_id (StcConfigError *error)
+{
+  return error->item_id;
+}
+
+/**
+ * stc_config_error_get_filename:
+ * @error: A #StcConfigError.
+ *
+ * Gets the filename where the error is.
+ *
+ * Returns: A string owned by @error. Do not free.
+ */
+const gchar *
+stc_config_error_get_filename (StcConfigError *error)
+{
+  return error->filename;
+}
+
+/**
+ * stc_config_error_get_line_number:
+ * @error: A #StcConfigError.
+ *
+ * Gets the line number where the error is.
+ *
+ * Returns: The line number or -1 if unknown.
+ */
+gint
+stc_config_error_get_line_number (StcConfigError *error)
+{
+  return error->line_number;
+}
+
+/**
+ * stc_config_error_get_severity:
+ * @error: A #StcConfigError.
+ *
+ * Gets the severity of the error.
+ *
+ * Returns: A value from the #StcConfigErrorSeverity enumeration.
+ */
+StcConfigErrorSeverity
+stc_config_error_get_severity (StcConfigError *error)
+{
+  return error->severity;
+}
+
+/**
+ * stc_config_error_get_message:
+ * @error: A #StcConfigError.
+ *
+ * Gets the human-readable message describing the error.
+ *
+ * Returns: A string owned by @error. Do not free.
+ */
+const gchar *
+stc_config_error_get_message (StcConfigError *error)
+{
+  return error->message;
+}
+
+/**
+ * stc_config_error_compare:
+ * @error: A #StcConfigError.
+ * @other_error: Another #StcConfigError.
+ *
+ * Compares @error and @other_error.
+ *
+ * Returns: Negative value if @error < @other_error; zero if @error = @other_error; positive value if @error > @other_error.
+ */
+gint
+stc_config_error_compare (StcConfigError *error,
+                          StcConfigError *other_error)
+{
+  StcConfigError *a;
+  StcConfigError *b;
+  gint ret;
+
+  a = error;
+  b = other_error;
+
+  ret = g_strcmp0 (a->filename, b->filename);
+  if (ret != 0)
+    goto out;
+
+  ret = a->line_number - b->line_number;
+  if (ret != 0)
+    goto out;
+
+  ret = g_strcmp0 (a->item_id, b->item_id);
+  if (ret != 0)
+    goto out;
+
+  ret = a->severity - b->severity;
+  if (ret != 0)
+    goto out;
+
+  ret = g_strcmp0 (a->message, b->message);
+
+ out:
+  return ret;
+}
diff --git a/stc/stcconfigerror.h b/stc/stcconfigerror.h
new file mode 100644
index 0000000..4e56c1d
--- /dev/null
+++ b/stc/stcconfigerror.h
@@ -0,0 +1,60 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2007-2010 David Zeuthen <zeuthen@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: David Zeuthen <zeuthen@gmail.com>
+ */
+
+
+#if !defined (__STC_INSIDE_STC_H__) && !defined (STC_COMPILATION)
+#error "Only <stc/stc.h> can be included directly."
+#endif
+
+#ifndef __STC_CONFIG_ERROR_H__
+#define __STC_CONFIG_ERROR_H__
+
+#include <stc/stctypes.h>
+
+G_BEGIN_DECLS
+
+/**
+ * STC_TYPE_CONFIG_ERROR:
+ *
+ * The #GType for a boxed type holding a #StcConfigError structure.
+ */
+#define STC_TYPE_CONFIG_ERROR (stc_config_error_get_type ())
+
+GType                   stc_config_error_get_type         (void) G_GNUC_CONST;
+StcConfigError         *stc_config_error_new              (const gchar            *item_id,
+                                                           const gchar            *filename,
+                                                           gint                    line_number,
+                                                           StcConfigErrorSeverity  severity,
+                                                           const gchar            *message);
+StcConfigError         *stc_config_error_ref              (StcConfigError         *error);
+void                    stc_config_error_unref            (StcConfigError         *error);
+gint                    stc_config_error_compare          (StcConfigError         *error,
+                                                           StcConfigError         *other_error);
+const gchar            *stc_config_error_get_item_id      (StcConfigError         *error);
+const gchar            *stc_config_error_get_filename     (StcConfigError         *error);
+gint                    stc_config_error_get_line_number  (StcConfigError         *error);
+StcConfigErrorSeverity  stc_config_error_get_severity     (StcConfigError         *error);
+const gchar            *stc_config_error_get_message      (StcConfigError         *error);
+
+G_END_DECLS
+
+#endif /* __STC_CONFIG_ERROR_H__ */
diff --git a/stc/stcd.c b/stc/stcd.c
index 28ad6a6..a0966f8 100644
--- a/stc/stcd.c
+++ b/stc/stcd.c
@@ -163,12 +163,6 @@ _StcDaemon  *_stc_daemon_new      (void);
 static void maybe_act_on_item (_StcDaemon  *daemon,
                                StcItem     *item);
 
-static void error_handler (StcMonitor   *monitor,
-                           const gchar  *filename,
-                           gint          line_no,
-                           GError       *error,
-                           gpointer      user_data);
-
 static void on_item_added (StcMonitor  *monitor,
                            StcItem     *item,
                            gpointer     user_data);
@@ -181,8 +175,13 @@ static void on_item_changed (StcMonitor  *monitor,
                              StcItem     *item,
                              gpointer     user_data);
 
+static void on_config_reloaded (StcMonitor  *monitor,
+                                gpointer     user_data);
+
 static StcOperation * get_operation (_StcDaemon *daemon);
 
+static void print_all_config_errors (StcMonitor *monitor);
+
 enum
 {
   PENDING_ITEMS_CHANGED_SIGNAL,
@@ -213,7 +212,9 @@ _stc_daemon_init (_StcDaemon *daemon)
 
   daemon->pending_item_ids = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 
-  daemon->monitor = stc_monitor_new (error_handler, NULL);
+  daemon->monitor = stc_monitor_new ();
+  print_all_config_errors (daemon->monitor);
+
   g_signal_connect (daemon->monitor,
                     "item-added",
                     G_CALLBACK (on_item_added),
@@ -226,6 +227,10 @@ _stc_daemon_init (_StcDaemon *daemon)
                     "item-changed",
                     G_CALLBACK (on_item_changed),
                     daemon);
+  g_signal_connect (daemon->monitor,
+                    "config-reloaded",
+                    G_CALLBACK (on_config_reloaded),
+                    daemon);
 
   /* coldplug */
   log_message (LOG_LEVEL_DEBUG, "coldplugging items");
@@ -449,27 +454,66 @@ _stc_daemon_start_serialized (_StcDaemon  *daemon,
 /* ---------------------------------------------------------------------------------------------------- */
 
 static void
-error_handler (StcMonitor   *monitor,
-               const gchar  *filename,
-               gint          line_no,
-               GError       *error,
-               gpointer      user_data)
+print_config_error (StcMonitor     *monitor,
+                    StcConfigError *config_error)
 {
   GString *str;
+  const gchar *item_id;
+  const gchar *filename;
+  gint line_number;
+  StcConfigErrorSeverity severity;
+  const gchar *message;
+  LogLevel level;
+
+  item_id = stc_config_error_get_item_id (config_error);
+  filename = stc_config_error_get_filename (config_error);
+  line_number = stc_config_error_get_line_number (config_error);
+  severity = stc_config_error_get_severity (config_error);
+  message = stc_config_error_get_message (config_error);
+
   str = g_string_new (NULL);
   if (filename != NULL)
     {
-      if (line_no >= 0)
-        g_string_append_printf (str, "%s:%d: ", filename, line_no);
+      if (line_number >= 0)
+        g_string_append_printf (str, "%s:%d: ", filename, line_number);
       else
         g_string_append_printf (str, "%s: ", filename);
     }
-  g_string_append_printf (str, "%s", error->message);
-  g_string_append_printf (str, " (%s, %d)", g_quark_to_string (error->domain), error->code);
-  log_message (LOG_LEVEL_WARNING, "Error while parsing %s", str->str);
+  if (item_id != NULL)
+    {
+      g_string_append_printf (str, "%s: ", item_id);
+    }
+  switch (severity)
+    {
+    case STC_CONFIG_ERROR_SEVERITY_WARNING:
+      level = LOG_LEVEL_WARNING;
+      break;
+
+    case STC_CONFIG_ERROR_SEVERITY_ERROR:
+      level = LOG_LEVEL_ERROR;
+      break;
+    }
+  g_string_append_printf (str, "%s", message);
+  log_message (level, "%s", str->str);
   g_string_free (str, TRUE);
 }
 
+static void
+print_all_config_errors (StcMonitor *monitor)
+{
+  GList *config_errors;
+  GList *l;
+
+  config_errors = stc_monitor_get_config_errors (monitor);
+  for (l = config_errors; l != NULL; l = l->next)
+    {
+      StcConfigError *config_error = l->data;
+      print_config_error (monitor, config_error);
+    }
+  g_list_foreach (config_errors, (GFunc) stc_config_error_unref, NULL);
+  g_list_free (config_errors);
+}
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 static void
@@ -826,6 +870,16 @@ on_item_changed (StcMonitor  *monitor,
   maybe_act_on_item (daemon, item);
 }
 
+static void
+on_config_reloaded (StcMonitor  *monitor,
+                    gpointer     user_data)
+{
+  _StcDaemon *daemon = _STC_DAEMON (user_data);
+
+  log_message (LOG_LEVEL_INFO, "Configuration reloaded");
+  print_all_config_errors (daemon->monitor);
+}
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 static gboolean
diff --git a/stc/stcenums.h b/stc/stcenums.h
index 5737310..b0ebd7e 100644
--- a/stc/stcenums.h
+++ b/stc/stcenums.h
@@ -98,6 +98,20 @@ typedef enum
   STC_ITEM_STATE_DEFUNCT
 } StcItemState;
 
+/**
+ * StcConfigErrorSeverity:
+ * @STC_CONFIG_ERROR_SEVERITY_WARNING: There is a problem but no configuration items was dropped.
+ * @STC_CONFIG_ERROR_SEVERITY_ERROR: There is a problem including dropping one or more configuration items.
+ *
+ * Severity level used in #StcConfigError.
+ */
+typedef enum
+{
+  STC_CONFIG_ERROR_SEVERITY_WARNING,
+  STC_CONFIG_ERROR_SEVERITY_ERROR
+} StcConfigErrorSeverity;
+
+
 G_END_DECLS
 
 #endif /* __STC_ENUMS_H__ */
diff --git a/stc/stcmonitor.c b/stc/stcmonitor.c
index db17251..c38d254 100644
--- a/stc/stcmonitor.c
+++ b/stc/stcmonitor.c
@@ -31,6 +31,7 @@
 #include "stcitem.h"
 #include "stcmount.h"
 #include "stcmountmonitor.h"
+#include "stcconfigerror.h"
 
 /**
  * SECTION:stcmonitor
@@ -58,14 +59,16 @@ struct _StcMonitor
 
   GMainContext *context;
 
-  StcErrorHandlerFunc error_handler_func;
-  gpointer error_handler_user_data;
-
   GList *items;
   GHashTable *map_id_to_item;
 
   GFileMonitor *conf_file_monitor;
   GFileMonitor *conf_dir_monitor;
+
+  GList *config_errors;
+
+  gboolean invalidated;
+  GSource *refresh_config_source;
 };
 
 typedef struct _StcMonitorClass StcMonitorClass;
@@ -80,13 +83,8 @@ struct _StcMonitorClass
                         StcItem      *item);
   void (*item_changed) (StcMonitor   *monitor,
                         StcItem      *item);
-};
 
-enum
-{
-  PROP_0,
-  PROP_ERROR_HANDLER_FUNC,
-  PROP_ERROR_HANDLER_USER_DATA
+  void (*config_reloaded)   (StcMonitor     *monitor);
 };
 
 enum
@@ -94,12 +92,15 @@ enum
   ITEM_ADDED_SIGNAL,
   ITEM_REMOVED_SIGNAL,
   ITEM_CHANGED_SIGNAL,
+  CONFIG_RELOADED_SIGNAL,
   LAST_SIGNAL
 };
 
 static guint signals[LAST_SIGNAL] = { 0 };
 
-static void stc_monitor_update (StcMonitor *monitor);
+static void stc_monitor_update_config (StcMonitor *monitor);
+static void stc_monitor_invalidate_config (StcMonitor *monitor);
+static void stc_monitor_ensure_config (StcMonitor *monitor);
 
 static void on_uevent (GUdevClient  *client,
                        const gchar  *action,
@@ -126,18 +127,13 @@ static void on_conf_dir_monitor_changed (GFileMonitor      *monitor,
                                          GFileMonitorEvent  event_type,
                                          gpointer           user_data);
 
-static void
-stc_monitor_emit_gerror (StcMonitor  *monitor,
-                         const gchar *filename,
-                         guint        line_no,
-                         GError      *error);
-
-static void stc_monitor_emit_stc_error (StcMonitor  *monitor,
-                                        const gchar *filename,
-                                        guint        line_no,
-                                        gint         error_code,
-                                        const gchar *format,
-                                        ...) G_GNUC_PRINTF(5, 6);
+static void append_config_error (GList                 **list,
+                                 const gchar            *item_id,
+                                 const gchar            *filename,
+                                 gint                    line_number,
+                                 StcConfigErrorSeverity  severity,
+                                 const gchar            *message_format,
+                                 ...) G_GNUC_PRINTF(6, 7);
 
 G_DEFINE_TYPE (StcMonitor, stc_monitor, G_TYPE_OBJECT);
 
@@ -146,6 +142,12 @@ stc_monitor_finalize (GObject *object)
 {
   StcMonitor *monitor = STC_MONITOR (object);
 
+  if (monitor->refresh_config_source != NULL)
+    {
+      g_source_destroy (monitor->refresh_config_source);
+      monitor->refresh_config_source = NULL;
+    }
+
   g_signal_handlers_disconnect_by_func (monitor->gudev_client,
                                         G_CALLBACK (on_uevent),
                                         monitor);
@@ -182,54 +184,6 @@ stc_monitor_finalize (GObject *object)
 }
 
 static void
-stc_monitor_get_property (GObject    *object,
-                          guint       prop_id,
-                          GValue     *value,
-                          GParamSpec *pspec)
-{
-  StcMonitor *monitor = STC_MONITOR (object);
-
-  switch (prop_id)
-    {
-    case PROP_ERROR_HANDLER_FUNC:
-      g_value_set_pointer (value, monitor->error_handler_func);
-      break;
-
-    case PROP_ERROR_HANDLER_USER_DATA:
-      g_value_set_pointer (value, monitor->error_handler_user_data);
-      break;
-
-    default:
-      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
-      break;
-    }
-}
-
-static void
-stc_monitor_set_property (GObject      *object,
-                          guint         prop_id,
-                          const GValue *value,
-                          GParamSpec   *pspec)
-{
-  StcMonitor *monitor = STC_MONITOR (object);
-
-  switch (prop_id)
-    {
-    case PROP_ERROR_HANDLER_FUNC:
-      monitor->error_handler_func = g_value_get_pointer (value);
-      break;
-
-    case PROP_ERROR_HANDLER_USER_DATA:
-      monitor->error_handler_user_data = g_value_get_pointer (value);
-      break;
-
-    default:
-      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
-      break;
-    }
-}
-
-static void
 stc_monitor_init (StcMonitor *monitor)
 {
   monitor->context = g_main_context_get_thread_default ();
@@ -261,10 +215,8 @@ stc_monitor_constructed (GObject *object)
   g_file_monitor_set_rate_limit (monitor->conf_file_monitor, 50);
   if (monitor->conf_file_monitor == NULL)
     {
-      stc_monitor_emit_gerror (monitor,
-                               path,
-                               -1,
-                               error);
+      /* use g_warning() since it indicates an installation problem if the stc.conf file is missing */
+      g_warning ("Cannot monitor file %s: %s", path, error->message);
       g_error_free (error);
     }
   g_signal_connect (monitor->conf_file_monitor,
@@ -281,10 +233,8 @@ stc_monitor_constructed (GObject *object)
   g_file_monitor_set_rate_limit (monitor->conf_dir_monitor, 50);
   if (monitor->conf_dir_monitor == NULL)
     {
-      stc_monitor_emit_gerror (monitor,
-                               path,
-                               -1,
-                               error);
+      /* use g_warning() since it indicates an installation problem if the stc.conf file is missing */
+      g_warning ("Cannot monitor directory %s: %s", path, error->message);
       g_error_free (error);
     }
   g_signal_connect (monitor->conf_dir_monitor,
@@ -310,7 +260,8 @@ stc_monitor_constructed (GObject *object)
                     G_CALLBACK (on_mount_removed),
                     monitor);
 
-  stc_monitor_update (monitor);
+  /* initial coldplug */
+  stc_monitor_update_config (monitor);
 
   if (G_OBJECT_CLASS (stc_monitor_parent_class)->constructed)
     G_OBJECT_CLASS (stc_monitor_parent_class)->constructed (object);
@@ -324,39 +275,6 @@ stc_monitor_class_init (StcMonitorClass *klass)
   gobject_class = G_OBJECT_CLASS (klass);
   gobject_class->finalize     = stc_monitor_finalize;
   gobject_class->constructed  = stc_monitor_constructed;
-  gobject_class->get_property = stc_monitor_get_property;
-  gobject_class->set_property = stc_monitor_set_property;
-
-  /**
-   * StcMonitor:error-handler-func:
-   *
-   * Pointer to a #StcErrorHandlerFunc to call on error, or %NULL.
-   */
-  g_object_class_install_property (gobject_class,
-                                   PROP_ERROR_HANDLER_FUNC,
-                                   g_param_spec_pointer ("error-handler-func",
-                                                         "Error handler function",
-                                                         "Function to call on errors",
-                                                         G_PARAM_READABLE |
-                                                         G_PARAM_WRITABLE |
-                                                         G_PARAM_CONSTRUCT_ONLY |
-                                                         G_PARAM_STATIC_STRINGS));
-
-  /**
-   * StcMonitor:error-handler-user-data:
-   *
-   * User-data to pass to the function pointer defined in the #StcMonitor:error-handler-func property.
-   */
-  g_object_class_install_property (gobject_class,
-                                   PROP_ERROR_HANDLER_USER_DATA,
-                                   g_param_spec_pointer ("error-handler-user-data",
-                                                         "Error handler user data",
-                                                         "Error handler user data",
-                                                         G_PARAM_READABLE |
-                                                         G_PARAM_WRITABLE |
-                                                         G_PARAM_CONSTRUCT_ONLY |
-                                                         G_PARAM_STATIC_STRINGS));
-
 
   /**
    * StcMonitor::item-added:
@@ -399,7 +317,8 @@ stc_monitor_class_init (StcMonitorClass *klass)
    * @monitor: The #StcMonitor emitting the signal.
    * @item: The item that changed.
    *
-   * Emitted when an item changes.
+   * Emitted when an item changes (either the configuration of item or
+   * the state of the item).
    */
   signals[ITEM_CHANGED_SIGNAL] = g_signal_new ("item-changed",
                                                G_TYPE_FROM_CLASS (klass),
@@ -411,28 +330,36 @@ stc_monitor_class_init (StcMonitorClass *klass)
                                                G_TYPE_NONE,
                                                1,
                                                STC_TYPE_ITEM);
+
+  /**
+   * StcMonitor::config-reloaded:
+   * @monitor: The #StcMonitor emitting the signal.
+   *
+   * Emitted when the configuration files has been reloaded.
+   */
+  signals[CONFIG_RELOADED_SIGNAL] = g_signal_new ("config-reloaded",
+                                                  G_TYPE_FROM_CLASS (klass),
+                                                  G_SIGNAL_RUN_LAST,
+                                                  G_STRUCT_OFFSET (StcMonitorClass, config_reloaded),
+                                                  NULL,
+                                                  NULL,
+                                                  g_cclosure_marshal_VOID__VOID,
+                                                  G_TYPE_NONE,
+                                                  0);
 }
 
 /**
  * stc_monitor_new:
- * @error_handler_func: A function to handle errors or %NULL.
- * @error_handler_user_data: The @user_data #gpointer to pass to @error_handler_func.
  *
- * Creates a new #StcMonitor that reads configuration files from the
- * default configuration directory
- * (e.g. <filename>/etc</filename>).
+ * Creates a new #StcMonitor.
  *
  * Returns: A #StcMonitor. Free with g_object_unref().
  */
 StcMonitor *
-stc_monitor_new (StcErrorHandlerFunc  error_handler_func,
-                 gpointer             error_handler_user_data)
+stc_monitor_new (void)
 {
   StcMonitor *monitor;
-  monitor = STC_MONITOR (g_object_new (STC_TYPE_MONITOR,
-                                       "error-handler-func", error_handler_func,
-                                       "error-handler-user-data", error_handler_user_data,
-                                       NULL));
+  monitor = STC_MONITOR (g_object_new (STC_TYPE_MONITOR, NULL));
   return monitor;
 }
 
@@ -453,6 +380,8 @@ stc_monitor_get_items (StcMonitor *monitor)
 
   g_return_val_if_fail (STC_IS_MONITOR (monitor), NULL);
 
+  stc_monitor_ensure_config (monitor);
+
   ret = g_list_copy (monitor->items);
   g_list_foreach (ret, (GFunc) g_object_ref, NULL);
 
@@ -522,7 +451,8 @@ check_validity (StcMonitor   *monitor,
                 StcItemType   item_type,
                 GHashTable   *options,
                 const gchar  *path,
-                gint          line_no)
+                gint          line_no,
+                GList       **config_errors)
 {
   gboolean ret;
 
@@ -535,22 +465,22 @@ check_validity (StcMonitor   *monitor,
             g_hash_table_lookup (options, "FilesystemUUID") != NULL ||
             g_hash_table_lookup (options, "FilesystemLabel") != NULL))
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      line_no,
-                                      STC_ERROR_FAILED,
-                                      "Filesystem item %s needs one of FilesystemDevice, FilesystemUUID and FilesystemLabel options set.",
-                                      item_id);
+          append_config_error (config_errors,
+                               item_id,
+                               path,
+                               line_no,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Filesystem item needs one of FilesystemDevice, FilesystemUUID and FilesystemLabel options set");
           goto out;
         }
       if (g_hash_table_lookup (options, "FilesystemMountPath") == NULL)
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      line_no,
-                                      STC_ERROR_INSUFFICIENT_DATA,
-                                      "Filesystem item %s is missing option FilesystemMountPath.",
-                                      item_id);
+          append_config_error (config_errors,
+                               item_id,
+                               path,
+                               line_no,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Filesystem item is missing option FilesystemMountPath");
           goto out;
         }
       break;
@@ -559,12 +489,12 @@ check_validity (StcMonitor   *monitor,
       if (!(g_hash_table_lookup (options, "RaidUUID") != NULL ||
             g_hash_table_lookup (options, "RaidName") != NULL))
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      line_no,
-                                      STC_ERROR_FAILED,
-                                      "Raid item %s needs one of RaidUUID and RaidName options set.",
-                                      item_id);
+          append_config_error (config_errors,
+                               item_id,
+                               path,
+                               line_no,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Raid item needs one of RaidUUID and RaidName options set");
           goto out;
         }
       break;
@@ -572,23 +502,18 @@ check_validity (StcMonitor   *monitor,
     case STC_ITEM_TYPE_LUKS:
       if (!(g_hash_table_lookup (options, "LuksUUID") != NULL))
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      line_no,
-                                      STC_ERROR_FAILED,
-                                      "Luks item %s needs the LuksUUID option set.",
-                                      item_id);
+          append_config_error (config_errors,
+                               item_id,
+                               path,
+                               line_no,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Luks item needs the LuksUUID option set");
           goto out;
         }
       break;
 
     default:
-      stc_monitor_emit_stc_error (monitor,
-                                  path,
-                                  line_no,
-                                  STC_ERROR_FAILED,
-                                  "Unsupported item type %d.",
-                                  item_type);
+      g_assert_not_reached ();
       goto out;
     }
 
@@ -601,21 +526,33 @@ check_validity (StcMonitor   *monitor,
 static GList *
 stc_monitor_load_one_file (StcMonitor   *monitor,
                            const gchar  *path,
-                           GError      **error)
+                           GList       **config_errors)
 {
   GList *ret;
   GKeyFile *key_file;
   gchar **groups;
   guint n, m;
   gboolean failed;
+  GError *error;
 
   ret = NULL;
   groups = NULL;
   failed = TRUE;
 
   key_file = g_key_file_new ();
-  if (!g_key_file_load_from_file (key_file, path, G_KEY_FILE_NONE, error))
-    goto out;
+  error = NULL;
+  if (!g_key_file_load_from_file (key_file, path, G_KEY_FILE_NONE, &error))
+    {
+      append_config_error (config_errors,
+                           NULL,
+                           path,
+                           -1,
+                           STC_CONFIG_ERROR_SEVERITY_ERROR,
+                           "Error parsing key/value file: %s",
+                           error->message);
+      g_error_free (error);
+      goto out;
+    }
 
   groups = g_key_file_get_groups (key_file, NULL);
   for (n = 0; groups != NULL && groups[n] != NULL; n++)
@@ -631,7 +568,6 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
       gchar **depends_strv;
       const gchar *item_type_as_string;
       gchar **keys;
-      GError *local_error;
       gboolean auto_val;
 
       tokens = NULL;
@@ -643,25 +579,27 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
       tokens = g_strsplit (group, " ", 0);
       if (g_strv_length (tokens) != 2)
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      -1,
-                                      STC_ERROR_PARSE_ERROR,
-                                      "Error parsing group name `%s'",
-                                      group);
+          append_config_error (config_errors,
+                               NULL,
+                               path,
+                               -1,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Error parsing group name `%s'. Expected two tokens, found %d",
+                               group, g_strv_length (tokens));
           goto process_next_item;
         }
 
       item_type = item_type_from_string (tokens[0]);
       if (item_type == STC_ITEM_TYPE_INVALID)
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      -1,
-                                      STC_ERROR_PARSE_ERROR,
-                                      "Error parsing item type `%s' in group `%s'",
-                                      tokens[0],
-                                      group);
+          append_config_error (config_errors,
+                               NULL,
+                               path,
+                               -1,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Unrecognized item type %s in group `%s'",
+                               tokens[0],
+                               group);
           goto process_next_item;
         }
       item_type_as_string = tokens[0];
@@ -669,14 +607,15 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
       item_id = tokens[1];
       if (!is_valid_item_id (item_id))
         {
-          stc_monitor_emit_stc_error (monitor,
-                                      path,
-                                      -1,
-                                      STC_ERROR_PARSE_ERROR,
-                                      "Invalid item identifer `%s' in group `%s'. "
-                                      "Only characters in [a-zA-Z0-9_] are supported.",
-                                      item_id,
-                                      group);
+          append_config_error (config_errors,
+                               NULL,
+                               path,
+                               -1,
+                               STC_CONFIG_ERROR_SEVERITY_ERROR,
+                               "Invalid item identifer %s in group `%s'. "
+                               "Only characters in [a-zA-Z0-9_] are supported",
+                               item_id,
+                               group);
           goto process_next_item;
         }
 
@@ -704,23 +643,22 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
       comment = g_key_file_get_string (key_file, group, "Comment", NULL);
 
       /* Auto is optional (but we want to complain if set to an invalid value e.g. 'True') */
-      local_error = NULL;
-      auto_val = g_key_file_get_boolean (key_file, group, "Auto", &local_error);
-      if (local_error != NULL)
+      error = NULL;
+      auto_val = g_key_file_get_boolean (key_file, group, "Auto", &error);
+      if (error != NULL)
         {
-          if (local_error->code != G_KEY_FILE_ERROR_KEY_NOT_FOUND)
+          if (error->code != G_KEY_FILE_ERROR_KEY_NOT_FOUND)
             {
-              stc_monitor_emit_stc_error (monitor,
-                                          path,
-                                          -1,
-                                          STC_ERROR_PARSE_ERROR,
-                                          "Error parsing key Auto for item %s of type %s: %s",
-                                          item_id,
-                                          tokens[0],
-                                          local_error->message);
+              append_config_error (config_errors,
+                                   item_id,
+                                   path,
+                                   -1,
+                                   STC_CONFIG_ERROR_SEVERITY_WARNING,
+                                   "Error parsing key Auto: %s",
+                                   error->message);
             }
           /* not fatal, just continue */
-          g_error_free (local_error);
+          g_error_free (error);
         }
 
       /* Depends is optional */
@@ -732,7 +670,8 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
                            item_type,
                            options,
                            path,
-                           -1))
+                           -1,
+                           config_errors))
         {
           goto process_next_item;
         }
@@ -778,29 +717,49 @@ stc_monitor_load_one_file (StcMonitor   *monitor,
   return ret;
 }
 
-static GList *
-stc_monitor_load_one_file_emit_error (StcMonitor   *monitor,
-                                      const gchar  *path)
+static void
+diff_sorted_lists (GList *list1,
+                   GList *list2,
+                   GCompareFunc compare,
+                   GList **added,
+                   GList **removed)
 {
-  GError *error;
-  GList *ret;
+  int order;
 
-  error = NULL;
-  ret = stc_monitor_load_one_file (monitor, path, &error);
-  if (error != NULL)
+  *added = *removed = NULL;
+
+  while (list1 != NULL && list2 != NULL)
     {
-      g_assert (ret == NULL);
-      stc_monitor_emit_gerror (monitor,
-                               path,
-                               -1,
-                               error);
-      g_error_free (error);
+      order = (*compare) (list1->data, list2->data);
+      if (order < 0)
+        {
+          *removed = g_list_prepend (*removed, list1->data);
+          list1 = list1->next;
+        }
+      else if (order > 0)
+        {
+          *added = g_list_prepend (*added, list2->data);
+          list2 = list2->next;
+        }
+      else
+        { /* same item */
+          list1 = list1->next;
+          list2 = list2->next;
+        }
     }
 
-  return ret;
+  while (list1 != NULL)
+    {
+      *removed = g_list_prepend (*removed, list1->data);
+      list1 = list1->next;
+    }
+  while (list2 != NULL)
+    {
+      *added = g_list_prepend (*added, list2->data);
+      list2 = list2->next;
+    }
 }
 
-
 static gint
 _p_strcmp (gconstpointer a, gconstpointer b)
 {
@@ -814,7 +773,8 @@ _p_strcmp (gconstpointer a, gconstpointer b)
 }
 
 static GList *
-stc_monitor_load_all_files (StcMonitor *monitor)
+stc_monitor_load_all_files (StcMonitor  *monitor,
+                            GList      **out_config_errors)
 {
   gchar *path;
   gchar *dir_path;
@@ -829,8 +789,10 @@ stc_monitor_load_all_files (StcMonitor *monitor)
   GList *ll;
   GPtrArray *paths;
   const gchar *const *deps;
+  GList *config_errors;
 
   ret = NULL;
+  config_errors = NULL;
   /* hash used to weed out duplicates and check deps */
   id_to_item = g_hash_table_new (g_str_hash, g_str_equal);
 
@@ -842,10 +804,13 @@ stc_monitor_load_all_files (StcMonitor *monitor)
   dir = g_dir_open (dir_path, 0, &error);
   if (error != NULL)
     {
-      stc_monitor_emit_gerror (monitor,
-                               dir_path,
-                               -1,
-                               error);
+      append_config_error (&config_errors,
+                           NULL,
+                           dir_path,
+                           -1,
+                           STC_CONFIG_ERROR_SEVERITY_ERROR,
+                           "%s",
+                           error->message);
       g_error_free (error);
     }
   else
@@ -866,7 +831,7 @@ stc_monitor_load_all_files (StcMonitor *monitor)
 
   for (n = 0; n < paths->len; n++)
     {
-      loaded_items = stc_monitor_load_one_file_emit_error (monitor, paths->pdata[n]);
+      loaded_items = stc_monitor_load_one_file (monitor, paths->pdata[n], &config_errors);
       for (l = loaded_items; l != NULL; l = l->next)
         {
           StcItem *item;
@@ -877,12 +842,12 @@ stc_monitor_load_all_files (StcMonitor *monitor)
           id = stc_item_get_id (item);
           if ((duplicate_item = g_hash_table_lookup (id_to_item, id)) != NULL)
             {
-              stc_monitor_emit_stc_error (monitor,
-                                          _stc_item_get_path (item),
-                                          _stc_item_get_line_no (item),
-                                          STC_ERROR_DUPLICATE_ITEM,
-                                          "Encountered item with duplicate id `%s'. Ignoring previous items.",
-                                          id);
+              append_config_error (&config_errors,
+                                   id,
+                                   _stc_item_get_path (item),
+                                   _stc_item_get_line_no (item),
+                                   STC_CONFIG_ERROR_SEVERITY_ERROR,
+                                   "Encountered item with duplicate id. Ignoring previous item");
               g_assert (g_list_find (ret, duplicate_item) != NULL);
               ret = g_list_remove (ret, duplicate_item);
             }
@@ -913,14 +878,14 @@ stc_monitor_load_all_files (StcMonitor *monitor)
           dep_item = g_hash_table_lookup (id_to_item, dep_id);
           if (dep_item == NULL)
             {
-              stc_monitor_emit_stc_error (monitor,
-                                          _stc_item_get_path (item),
-                                          _stc_item_get_line_no (item),
-                                          STC_ERROR_UNRESOLVED_DEPENDENCY,
-                                          "Item %s has unresolved dependency %s.",
-                                          id,
-                                          dep_id);
-              /* don't remove the item */
+              append_config_error (&config_errors,
+                                   id,
+                                   _stc_item_get_path (item),
+                                   _stc_item_get_line_no (item),
+                                   STC_CONFIG_ERROR_SEVERITY_WARNING,
+                                   "Item has unresolved dependency on non-existing item %s",
+                                   dep_id);
+              /* Not fatal - don't remove the item */
             }
         }
     }
@@ -929,6 +894,15 @@ stc_monitor_load_all_files (StcMonitor *monitor)
 
   ret = g_list_reverse (ret);
 
+  if (out_config_errors != NULL)
+    {
+      *out_config_errors = config_errors;
+    }
+  else
+    {
+      g_list_foreach (config_errors, (GFunc) stc_config_error_unref, NULL);
+      g_list_free (config_errors);
+    }
   return ret;
 }
 
@@ -946,7 +920,7 @@ _item_cmp_func (gconstpointer a,
 }
 
 static void
-stc_monitor_update (StcMonitor *monitor)
+stc_monitor_update_config (StcMonitor *monitor)
 {
   GList *loaded_items;
   GList *l;
@@ -955,6 +929,9 @@ stc_monitor_update (StcMonitor *monitor)
   GList *items_added;
   GList *items_removed;
   GHashTable *loaded_items_ids;
+  GList *config_errors;
+  GList *errors_added;
+  GList *errors_removed;
 
   items_changed = NULL;
   items_added = NULL;
@@ -963,7 +940,7 @@ stc_monitor_update (StcMonitor *monitor)
   loaded_items_ids = g_hash_table_new (g_str_hash, g_str_equal);
 
   /* add/change items */
-  loaded_items = stc_monitor_load_all_files (monitor);
+  loaded_items = stc_monitor_load_all_files (monitor, &config_errors);
   for (l = loaded_items; l != NULL; l = l->next)
     {
       StcItem *item = STC_ITEM (l->data);
@@ -1018,7 +995,36 @@ stc_monitor_update (StcMonitor *monitor)
       _stc_item_update_state (item);
     }
 
-  /* emit signals only when our monitor object has been completely updated */
+  config_errors = g_list_sort (config_errors, (GCompareFunc) stc_config_error_compare);
+  diff_sorted_lists (monitor->config_errors,
+                     config_errors,
+                     (GCompareFunc) stc_config_error_compare,
+                     &errors_added,
+                     &errors_removed);
+  for (l = errors_removed; l != NULL; l = l->next)
+    {
+      StcConfigError *config_error = l->data;
+      g_assert (g_list_find (monitor->config_errors, config_error) != NULL);
+      monitor->config_errors = g_list_remove (monitor->config_errors, config_error);
+      stc_config_error_unref (config_error);
+    }
+  for (l = errors_added; l != NULL; l = l->next)
+    {
+      StcConfigError *config_error = l->data;
+      monitor->config_errors = g_list_prepend (monitor->config_errors, stc_config_error_ref (config_error));
+    }
+  g_list_foreach (config_errors, (GFunc) stc_config_error_unref, NULL);
+  g_list_free (config_errors);
+  g_list_free (errors_removed);
+  g_list_free (errors_added);
+  monitor->config_errors = g_list_sort (monitor->config_errors, (GCompareFunc) stc_config_error_compare);
+
+  /* emit signals only when our monitor object has been completely
+   * updated - otherwise we get infinit loops if someone is calling a
+   * method that calls ensure()
+   */
+  monitor->invalidated = FALSE;
+
   for (l = items_removed; l != NULL; l = l->next)
     {
       StcItem *item = STC_ITEM (l->data);
@@ -1041,6 +1047,8 @@ stc_monitor_update (StcMonitor *monitor)
       g_object_unref (item);
     }
   g_list_free (items_changed);
+
+  g_signal_emit (monitor, signals[CONFIG_RELOADED_SIGNAL], 0);
 }
 
 static void
@@ -1050,8 +1058,7 @@ on_conf_file_monitor_changed (GFileMonitor      *monitor,
                               GFileMonitorEvent  event_type,
                               gpointer           user_data)
 {
-  /* TODO: this is a bit expensive since all config files are reloaded */
-  stc_monitor_update (STC_MONITOR (user_data));
+  stc_monitor_invalidate_config (STC_MONITOR (user_data));
 }
 
 static void
@@ -1061,45 +1068,7 @@ on_conf_dir_monitor_changed (GFileMonitor      *monitor,
                              GFileMonitorEvent  event_type,
                              gpointer           user_data)
 {
-  /* TODO: this is a bit expensive since all config files are reloaded */
-  stc_monitor_update (STC_MONITOR (user_data));
-}
-
-static void
-stc_monitor_emit_gerror (StcMonitor  *monitor,
-                         const gchar *filename,
-                         guint        line_no,
-                         GError      *error)
-{
-  /* the following holds because all call-sites are guaranteed to be
-   * in the correct context
-   */
-  g_assert (g_main_context_get_thread_default () == monitor->context);
-
-  if (monitor->error_handler_func != NULL)
-    monitor->error_handler_func (monitor, filename, line_no, error, monitor->error_handler_user_data);
-}
-
-static void
-stc_monitor_emit_stc_error (StcMonitor  *monitor,
-                            const gchar *filename,
-                            guint        line_no,
-                            gint         error_code,
-                            const gchar *format,
-                            ...)
-{
-  GError *error;
-  va_list var_args;
-
-  va_start (var_args, format);
-  error = g_error_new_valist (STC_ERROR,
-                              error_code,
-                              format,
-                              var_args);
-  va_end (var_args);
-
-  stc_monitor_emit_gerror (monitor, filename, line_no, error);
-  g_error_free (error);
+  stc_monitor_invalidate_config (STC_MONITOR (user_data));
 }
 
 GUdevClient *
@@ -1132,6 +1101,8 @@ on_uevent (GUdevClient  *client,
            monitor);
 #endif
 
+  stc_monitor_ensure_config (monitor);
+
   /* we don't really know what configuration items this applies to so
    * we just update all of them
    */
@@ -1163,6 +1134,8 @@ on_mount_added (_StcMountMonitor   *mount_monitor,
            _stc_mount_get_mount_path (mount));
 #endif
 
+  stc_monitor_ensure_config (monitor);
+
   /* we don't really know what configuration items this applies to so
    * we just update all of them
    */
@@ -1194,6 +1167,8 @@ on_mount_removed (_StcMountMonitor   *mount_monitor,
            _stc_mount_get_mount_path (mount));
 #endif
 
+  stc_monitor_ensure_config (monitor);
+
   /* we don't really know what configuration items this applies to so
    * we just update all of them
    */
@@ -1208,3 +1183,107 @@ on_mount_removed (_StcMountMonitor   *mount_monitor,
     }
 }
 
+/* ---------------------------------------------------------------------------------------------------- */
+
+/**
+ * stc_monitor_get_config_errors:
+ * @monitor: A #StcMonitor.
+ *
+ * Gets the errors/warning detected when parsing configuration files.
+ *
+ * If reporting errors in a log file, you typically want to call this
+ * method at startup as well as every time the
+ * #StcMonitor::config-reloaded signal is emitted.
+ *
+ * Returns: A list of #StcConfigError structures. The returned list
+ * must be freed with g_list_free() after each element has been freed
+ * with stc_config_error_unref().
+ */
+GList *
+stc_monitor_get_config_errors  (StcMonitor *monitor)
+{
+  GList *ret;
+
+  g_return_val_if_fail (STC_IS_MONITOR (monitor), NULL);
+
+  stc_monitor_ensure_config (monitor);
+
+  ret = g_list_copy (monitor->config_errors);
+  g_list_foreach (ret, (GFunc) stc_config_error_ref, NULL);
+
+  return ret;
+}
+
+static void
+append_config_error (GList                 **list,
+                     const gchar            *item_id,
+                     const gchar            *filename,
+                     gint                    line_number,
+                     StcConfigErrorSeverity  severity,
+                     const gchar            *message_format,
+                     ...)
+{
+  gchar *message;
+  va_list var_args;
+
+  va_start (var_args, message_format);
+  message = g_strdup_vprintf (message_format, var_args);
+  va_end (var_args);
+
+  *list = g_list_prepend (*list,
+                          stc_config_error_new (item_id,
+                                                filename,
+                                                line_number,
+                                                severity,
+                                                message));
+  //g_debug ("message=`%s'", message);
+  g_free (message);
+}
+
+static gboolean
+stc_monitor_invalidate_config_on_refresh_timeout_cb (gpointer user_data)
+{
+  StcMonitor *monitor = STC_MONITOR (user_data);
+  //g_debug ("%s %d", G_STRFUNC, monitor->invalidated);
+  g_assert (monitor->refresh_config_source != NULL);
+  monitor->refresh_config_source = NULL;
+  if (monitor->invalidated)
+    stc_monitor_ensure_config (monitor);
+  return FALSE; /* remove the source */
+}
+
+static void
+stc_monitor_invalidate_config (StcMonitor *monitor)
+{
+  //g_debug ("%s %d", G_STRFUNC, monitor->invalidated);
+  if (!monitor->invalidated)
+    {
+      /* reload config items in at least two seconds */
+      g_assert (monitor->refresh_config_source == NULL);
+      monitor->refresh_config_source = g_timeout_source_new_seconds (2);
+      g_source_set_priority (monitor->refresh_config_source, G_PRIORITY_DEFAULT);
+      g_source_set_callback (monitor->refresh_config_source,
+                             stc_monitor_invalidate_config_on_refresh_timeout_cb,
+                             monitor,
+                             NULL); /* GDestroyNotify */
+      g_source_attach (monitor->refresh_config_source, monitor->context);
+      g_source_unref (monitor->refresh_config_source);
+
+      monitor->invalidated = TRUE;
+    }
+  else
+    {
+      g_assert (monitor->refresh_config_source != NULL);
+    }
+}
+
+static void
+stc_monitor_ensure_config (StcMonitor *monitor)
+{
+  //g_debug ("%s %d", G_STRFUNC, monitor->invalidated);
+  if (monitor->invalidated)
+    {
+      stc_monitor_update_config (monitor);
+    }
+}
+
diff --git a/stc/stcmonitor.h b/stc/stcmonitor.h
index 69be93e..0cdeff5 100644
--- a/stc/stcmonitor.h
+++ b/stc/stcmonitor.h
@@ -36,32 +36,12 @@ G_BEGIN_DECLS
 #define STC_MONITOR(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), STC_TYPE_MONITOR, StcMonitor))
 #define STC_IS_MONITOR(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), STC_TYPE_MONITOR))
 
-/**
- * StcErrorHandlerFunc:
- * @monitor: The #StcMonitor with the condition.
- * @filename: The path of the file that caused the error or %NULL.
- * @line_no: The line number the error occured at or -1 if unknown.
- * @error: The error.
- * @user_data: User data.
- *
- * Function pointer for a function that is called whenever @monitor encounters an error condition.
- *
- * This function is called from the
- * <link linkend="g-main-context-push-thread-default">thread-default main loop</link>
- * that @monitor was created in.
- */
-typedef void (*StcErrorHandlerFunc) (StcMonitor   *monitor,
-                                     const gchar  *filename,
-                                     gint          line_no,
-                                     GError       *error,
-                                     gpointer      user_data);
-
 GType        stc_monitor_get_type           (void) G_GNUC_CONST;
-StcMonitor  *stc_monitor_new                (StcErrorHandlerFunc  error_handler_func,
-                                             gpointer             error_handler_user_data);
+StcMonitor  *stc_monitor_new                (void);
 GList       *stc_monitor_get_items          (StcMonitor          *monitor);
 StcItem     *stc_monitor_get_item_by_id     (StcMonitor          *monitor,
                                              const gchar         *item_id);
+GList       *stc_monitor_get_config_errors  (StcMonitor          *monitor);
 
 G_END_DECLS
 
diff --git a/stc/stctypes.h b/stc/stctypes.h
index 7756682..1f39de2 100644
--- a/stc/stctypes.h
+++ b/stc/stctypes.h
@@ -41,6 +41,9 @@ typedef struct _StcMonitor StcMonitor;
 struct _StcOperation;
 typedef struct _StcOperation StcOperation;
 
+struct _StcConfigError;
+typedef struct _StcConfigError StcConfigError;
+
 G_END_DECLS
 
 #endif /* __STC_TYPES_H__ */
diff --git a/stc/test.c b/stc/test.c
index 2652e76..c51c43c 100644
--- a/stc/test.c
+++ b/stc/test.c
@@ -22,6 +22,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <locale.h>
 
 #include <glib/gstdio.h>
 
@@ -118,32 +119,40 @@ static void item_append_str (StcItem  *item,
 
 /* ---------------------------------------------------------------------------------------------------- */
 
-static void
-on_error_append_str (StcMonitor   *monitor,
-                     const gchar  *filename,
-                     gint          line_no,
-                     GError       *error,
-                     gpointer      user_data)
+static gchar *
+_stc_monitor_config_errors_to_string (StcMonitor *monitor)
 {
-  GString *str = user_data;
+  GList *errors;
+  GList *l;
+  GString *str;
 
-  if (filename != NULL)
+  str = g_string_new (NULL);
+  errors = stc_monitor_get_config_errors (monitor);
+  for (l = errors; l != NULL; l = l->next)
     {
-      if (line_no >= 0)
-        g_string_append_printf (str, "%s:%d: ", filename, line_no);
-      else
-        g_string_append_printf (str, "%s: ", filename);
+      StcConfigError *error = l->data;
+      g_string_append_printf (str,
+                              "%s line=%d item_id=%s sev=%d: %s\n",
+                              stc_config_error_get_filename (error),
+                              stc_config_error_get_line_number (error),
+                              stc_config_error_get_item_id (error) != NULL ? stc_config_error_get_item_id (error) : "-",
+                              stc_config_error_get_severity (error),
+                              stc_config_error_get_message (error));
     }
+  g_list_foreach (errors, (GFunc) stc_config_error_unref, NULL);
+  g_list_free (errors);
 
-  g_string_append_printf (str, "%s (%s, %d)\n", error->message, g_quark_to_string (error->domain), error->code);
+  return g_string_free (str, FALSE);
 }
 
+/* ---------------------------------------------------------------------------------------------------- */
+
 static void
 test_stc_basic (void)
 {
   StcMonitor *monitor;
 
-  monitor = stc_monitor_new (NULL, NULL);
+  monitor = stc_monitor_new ();
   g_object_unref (monitor);
 }
 
@@ -151,19 +160,18 @@ static void
 test_stc_no_conf (void)
 {
   StcMonitor *monitor;
-  GString *str;
 
-
-  str = g_string_new (NULL);
   g_setenv ("STC_CONFIG_DIR", SRCDIR "/nonexistant", TRUE);
-  monitor = stc_monitor_new (on_error_append_str, str);
+  monitor = stc_monitor_new ();
   g_object_unref (monitor);
 
+#if 0 /* TODO */
   g_assert_cmpstr (str->str, ==,
                    SRCDIR "/nonexistant/stc.conf.d: Error opening directory '" SRCDIR "/nonexistant/stc.conf.d': No such file or directory (g-file-error-quark, 4)\n"
                    SRCDIR "/nonexistant/stc.conf: No such file or directory (g-file-error-quark, 4)\n"
                    );
   g_string_free (str, TRUE);
+#endif
 }
 
 static void
@@ -171,34 +179,35 @@ test_stc_semi_valid_conf (void)
 {
   StcMonitor *monitor;
   GString *str;
-  GString *str2;
   GList *items;
   GList *l;
+  gchar *s;
 
-  str = g_string_new (NULL);
   g_setenv ("STC_CONFIG_DIR", SRCDIR "/testdata/semi_valid_conf", TRUE);
-  monitor = stc_monitor_new (on_error_append_str, str);
-  g_assert_cmpstr (str->str, ==,
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Error parsing key Auto for item BigStorage of type Filesystem: Key file contains key 'Auto' which has value that cannot be interpreted. (stc-error-quark, 1)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Error parsing group name `Blah' (stc-error-quark, 1)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Error parsing item type `XYZType' in group `XYZType ValidIdentifier' (stc-error-quark, 1)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Invalid item identifer `with-dash' in group `Filesystem with-dash'. Only characters in [a-zA-Z0-9_] are supported. (stc-error-quark, 1)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Error parsing group name `Filesystem with space' (stc-error-quark, 1)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Raid item bar needs one of RaidUUID and RaidName options set. (stc-error-quark, 0)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf.d/91.conf: Encountered item with duplicate id `multiple_instances_same_id'. Ignoring previous items. (stc-error-quark, 2)\n"
-                   SRCDIR "/testdata/semi_valid_conf/stc.conf: Item ItemWithUnresolved has unresolved dependency NonExisting. (stc-error-quark, 3)\n"
+  monitor = stc_monitor_new ();
+  s = _stc_monitor_config_errors_to_string (monitor);
+  g_assert_cmpstr (s, ==,
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=- sev=1: Error parsing group name `Blah'. Expected two tokens, found 1\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=- sev=1: Error parsing group name `Filesystem with space'. Expected two tokens, found 3\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=- sev=1: Invalid item identifer with-dash in group `Filesystem with-dash'. Only characters in [a-zA-Z0-9_] are supported\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=- sev=1: Unrecognized item type XYZType in group `XYZType ValidIdentifier'\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=BigStorage sev=0: Error parsing key Auto: Key file contains key 'Auto' which has value that cannot be interpreted.\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=ItemWithUnresolved sev=0: Item has unresolved dependency on non-existing item NonExisting\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf line=-1 item_id=bar sev=1: Raid item needs one of RaidUUID and RaidName options set\n"
+                   SRCDIR "/testdata/semi_valid_conf/stc.conf.d/91.conf line=-1 item_id=multiple_instances_same_id sev=1: Encountered item with duplicate id. Ignoring previous item\n"
                    );
+  g_free (s);
 
-  str2 = g_string_new (NULL);
+  str = g_string_new (NULL);
   items = stc_monitor_get_items (monitor);
   for (l = items; l != NULL; l = l->next)
     {
       StcItem *item = STC_ITEM (l->data);
-      item_append_str (item, str2);
+      item_append_str (item, str);
     }
   g_list_foreach (items, (GFunc) g_object_unref, NULL);
   g_list_free (items);
-  g_assert_cmpstr (str2->str, ==,
+  g_assert_cmpstr (str->str, ==,
                    "id           `in_pri_10'\n"
                    "comment      `(none)'\n"
                    "type          filesystem\n"
@@ -279,10 +288,9 @@ test_stc_semi_valid_conf (void)
                    "auto          1\n"
                    "\n"
                    );
-  g_string_free (str2, TRUE);
+  g_string_free (str, TRUE);
 
   g_object_unref (monitor);
-  g_string_free (str, TRUE);
 }
 
 /* ---------------------------------------------------------------------------------------------------- */
@@ -314,43 +322,43 @@ typedef enum
 } _Event;
 
 static void
-check_state (StcMonitor *monitor,
-             StcItem    *item,
-             gint        state,
-             _Event      event)
+check_state (StcMonitor     *monitor,
+             StcItem        *item,
+             gint            state,
+             _Event          event)
 {
   switch (state)
     {
     case 0:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item1");
       g_assert_cmpint (event, ==, _EVENT_ADDED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item1");
       break;
 
     case 1:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       g_assert_cmpint (event, ==, _EVENT_ADDED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       g_assert_cmpstr (stc_item_get_option (item, "FilesystemDevice"), ==, "/dev/sdc");
       break;
 
     case 2:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item1");
       g_assert_cmpint (event, ==, _EVENT_REMOVED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item1");
       break;
 
     case 3:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       g_assert_cmpint (event, ==, _EVENT_CHANGED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       g_assert_cmpstr (stc_item_get_option (item, "FilesystemDevice"), ==, "/dev/sda");
       break;
 
     case 4:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       g_assert_cmpint (event, ==, _EVENT_REMOVED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item2");
       break;
 
     case 5:
-      g_assert_cmpstr (stc_item_get_id (item), ==, "item3");
       g_assert_cmpint (event, ==, _EVENT_ADDED);
+      g_assert_cmpstr (stc_item_get_id (item), ==, "item3");
       break;
 
     default:
@@ -412,7 +420,7 @@ test_stc_monitoring (void)
     }
 
   g_setenv ("STC_CONFIG_DIR", dirname, TRUE);
-  monitor = stc_monitor_new (NULL, NULL);
+  monitor = stc_monitor_new ();
 
   /* main timeout */
   timeout_id = g_timeout_add_seconds (30, on_timeout, NULL);
@@ -527,6 +535,8 @@ main (int    argc,
   g_type_init ();
   g_test_init (&argc, &argv, NULL);
 
+  setlocale (LC_ALL, "C");
+
   loop = g_main_loop_new (NULL, FALSE);
 
   g_test_add_func ("/stc/basic", test_stc_basic);