glib2: add rbg_gc_guard() and rbg_gc_unguard()

glib2/ext/glib2/glib2.def

@@ -168,6 +168,9 @@ EXPORTS
 	rbg_variant_from_ruby
 	rbg_variant_type_from_ruby
 
+	rbg_gc_guard
+	rbg_gc_unguard
+
 	g_source_get_type
 	g_connect_flags_get_type
 	g_poll_fd_get_type

glib2/ext/glib2/rbglib-gc.c

@@ -0,0 +1,82 @@
+/* -*- c-file-style: "ruby"; indent-tabs-mode: nil -*- */
+/*
+ *  Copyright (C) 2018  Ruby-GNOME2 Project Team
+ *
+ *  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 2.1 of the License, 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., 51 Franklin Street, Fifth Floor, Boston,
+ *  MA  02110-1301  USA
+ */
+
+#include "rbgprivate.h"
+
+static GHashTable *rbg_objects = NULL;
+
+static void
+gc_marker_mark_each(gpointer key, gpointer value, gpointer user_data)
+{
+    VALUE rb_object = (VALUE)value;
+    rb_gc_mark(rb_object);
+}
+
+static void
+gc_marker_mark(void *data)
+{
+    GHashTable *hash_table = data;
+    g_hash_table_foreach(hash_table, gc_marker_mark_each, NULL);
+}
+
+static void
+gc_marker_free(void *data)
+{
+    GHashTable *hash_table = data;
+    g_hash_table_unref(hash_table);
+}
+
+static const rb_data_type_t rbg_gc_marker_type = {
+    "GLib::GCMarker",
+    {
+        gc_marker_mark,
+        gc_marker_free,
+        NULL,
+    },
+    NULL,
+    NULL,
+    RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+void
+rbg_gc_guard(gpointer key, VALUE rb_object)
+{
+    g_hash_table_insert(rbg_objects,
+                        key,
+                        (gpointer)rb_object);
+}
+
+void
+rbg_gc_unguard(gpointer key)
+{
+    g_hash_table_remove(rbg_objects, key);
+}
+
+void
+Init_glib_gc(void)
+{
+    VALUE gc_marker;
+
+    rbg_objects = g_hash_table_new(g_direct_hash, g_direct_equal);
+    gc_marker = TypedData_Wrap_Struct(rb_cData,
+                                      &rbg_gc_marker_type,
+                                      rbg_objects);
+    rb_ivar_set(mGLib, rb_intern("gc_marker"), gc_marker);
+}

glib2/ext/glib2/rbglib.c

@@ -1146,6 +1146,9 @@ union       GDoubleIEEE754;
     rb_define_const(RG_TARGET_NAMESPACE, "PRIORITY_LOW", INT2FIX(G_PRIORITY_LOW));
 
 /*    Init_mem(); */
+
+    Init_glib_gc();
+
     Init_gutil();
     Init_gutil_callback();
 

glib2/ext/glib2/rbglib.h

@@ -235,6 +235,9 @@ extern GVariant *rbg_variant_from_ruby(VALUE rb_variant);
 extern GVariantType *rbg_variant_type_from_ruby(VALUE rb_variant_type);
 
 
+extern void rbg_gc_guard(gpointer key, VALUE rb_object);
+extern void rbg_gc_unguard(gpointer key);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */

glib2/ext/glib2/rbgprivate.h

@@ -123,6 +123,8 @@ G_GNUC_INTERNAL void rg_enum_add_constants(VALUE mod, GType enum_type, const gch
 G_GNUC_INTERNAL void rg_flags_add_constants(VALUE mod, GType flags_type, const gchar *strip_prefix);
 G_GNUC_INTERNAL char *rg_obj_constant_lookup(const char *name);
 
+G_GNUC_INTERNAL void Init_glib_gc(void);
+
 G_GNUC_INTERNAL void Init_gutil(void);
 G_GNUC_INTERNAL void Init_gutil_callback(void);
 G_GNUC_INTERNAL void Init_glib_gettext(void);