gmarkup: Make GMarkupParseContext a boxed type

At the same time, add a refcount and public ref/unref methods.
This makes it usable from introspectable.

https://bugzilla.gnome.org/show_bug.cgi?id=690084

docs/reference/glib/glib-sections.txt

@@ -1127,6 +1127,8 @@ g_markup_parse_context_new
 g_markup_parse_context_parse
 g_markup_parse_context_push
 g_markup_parse_context_pop
+g_markup_parse_context_ref
+g_markup_parse_context_unref
 <SUBSECTION>
 GMarkupCollectType
 g_markup_collect_attributes

docs/reference/gobject/gobject-sections.txt

@@ -373,6 +373,7 @@ G_TYPE_VARIANT_BUILDER
 G_TYPE_KEY_FILE
 G_TYPE_MAIN_CONTEXT
 G_TYPE_MAIN_LOOP
+G_TYPE_MARKUP_PARSE_CONTEXT
 G_TYPE_SOURCE
 G_TYPE_POLLFD
 G_TYPE_THREAD

glib/glib.symbols

@@ -684,6 +684,8 @@ g_markup_parse_context_new
 g_markup_parse_context_parse
 g_markup_parse_context_push
 g_markup_parse_context_pop
+g_markup_parse_context_ref
+g_markup_parse_context_unref
 g_markup_printf_escaped
 g_markup_vprintf_escaped
 g_markup_collect_attributes

glib/gmarkup.c

@@ -29,6 +29,7 @@
 
 #include "gmarkup.h"
 
+#include "gatomic.h"
 #include "gslice.h"
 #include "galloca.h"
 #include "gstrfuncs.h"
@@ -117,6 +118,8 @@ struct _GMarkupParseContext
 {
   const GMarkupParser *parser;
 
+  volatile gint ref_count;
+
   GMarkupParseFlags flags;
 
   gint line_number;
@@ -224,6 +227,7 @@ g_markup_parse_context_new (const GMarkupParser *parser,
 
   context = g_new (GMarkupParseContext, 1);
 
+  context->ref_count = 1;
   context->parser = parser;
   context->flags = flags;
   context->user_data = user_data;
@@ -266,6 +270,46 @@ g_markup_parse_context_new (const GMarkupParser *parser,
   return context;
 }
 
+/**
+ * g_markup_parse_context_ref:
+ * @context: a #GMarkupParseContext
+ *
+ * Increases the reference count of @context.
+ *
+ * Returns: the same @context
+ *
+ * Since: 2.36
+ **/
+GMarkupParseContext *
+g_markup_parse_context_ref (GMarkupParseContext *context)
+{
+  g_return_val_if_fail (context != NULL, NULL);
+  g_return_val_if_fail (context->ref_count > 0, NULL);
+
+  g_atomic_int_inc (&context->ref_count);
+
+  return context;
+}
+
+/**
+ * g_markup_parse_context_unref:
+ * @context: a #GMarkupParseContext
+ *
+ * Decreases the reference count of @context.  When its reference count
+ * drops to 0, it is freed.
+ *
+ * Since: 2.36
+ **/
+void
+g_markup_parse_context_unref (GMarkupParseContext *context)
+{
+  g_return_if_fail (context != NULL);
+  g_return_if_fail (context->ref_count > 0);
+
+  if (g_atomic_int_dec_and_test (&context->ref_count))
+    g_markup_parse_context_free (context);
+}
+
 static void
 string_full_free (gpointer ptr)
 {

glib/gmarkup.h

@@ -182,6 +182,10 @@ GMarkupParseContext *g_markup_parse_context_new   (const GMarkupParser *parser,
                                                    GMarkupParseFlags    flags,
                                                    gpointer             user_data,
                                                    GDestroyNotify       user_data_dnotify);
+GLIB_AVAILABLE_IN_2_36
+GMarkupParseContext *g_markup_parse_context_ref   (GMarkupParseContext *context);
+GLIB_AVAILABLE_IN_2_36
+void                 g_markup_parse_context_unref (GMarkupParseContext *context);
 void                 g_markup_parse_context_free  (GMarkupParseContext *context);
 gboolean             g_markup_parse_context_parse (GMarkupParseContext *context,
                                                    const gchar         *text,

gobject/gboxed.c

@@ -160,6 +160,7 @@ G_DEFINE_BOXED_TYPE (GMainLoop, g_main_loop, g_main_loop_ref, g_main_loop_unref)
 G_DEFINE_BOXED_TYPE (GMainContext, g_main_context, g_main_context_ref, g_main_context_unref)
 G_DEFINE_BOXED_TYPE (GSource, g_source, g_source_ref, g_source_unref)
 G_DEFINE_BOXED_TYPE (GPollFD, g_pollfd, pollfd_copy, g_free)
+G_DEFINE_BOXED_TYPE (GMarkupParseContext, g_markup_parse_context, g_markup_parse_context_ref, g_markup_parse_context_unref)
 
 G_DEFINE_BOXED_TYPE (GThread, g_thread, g_thread_ref, g_thread_unref)
 G_DEFINE_BOXED_TYPE (GChecksum, g_checksum, g_checksum_copy, g_checksum_free)

gobject/glib-types.h

@@ -236,6 +236,15 @@ typedef gsize GType;
  */
 #define G_TYPE_POLLFD (g_pollfd_get_type ())
 
+/**
+ * G_TYPE_MARKUP_PARSE_CONTEXT:
+ *
+ * The #GType for a boxed type holding a #GMarkupParseContext.
+ *
+ * Since: 2.36
+ */
+#define G_TYPE_MARKUP_PARSE_CONTEXT (g_markup_parse_context_get_type ())
+
 /**
  * G_TYPE_KEY_FILE:
  *
@@ -294,6 +303,8 @@ GLIB_AVAILABLE_IN_2_36
 GType   g_thread_get_type          (void) G_GNUC_CONST;
 GLIB_AVAILABLE_IN_2_36
 GType   g_checksum_get_type        (void) G_GNUC_CONST;
+GLIB_AVAILABLE_IN_2_36
+GType   g_markup_parse_context_get_type (void) G_GNUC_CONST;
 
 GLIB_DEPRECATED_FOR('G_TYPE_VARIANT')
 GType   g_variant_get_gtype        (void) G_GNUC_CONST;

gobject/gobject.symbols

@@ -32,6 +32,7 @@ g_variant_type_get_gtype
 g_key_file_get_type
 g_main_loop_get_type
 g_main_context_get_type
+g_markup_parse_context_get_type
 g_source_get_type
 g_pollfd_get_type
 g_closure_get_type