luaclass: take care of inheritance garbage collection

Signed-off-by: Julien Danjou <julien@danjou.info>

common/luaclass.c

@@ -163,11 +163,31 @@ luaA_class_add_property(lua_class_t *lua_class,
                                     });
 }
 
+/** Garbage collect a Lua object.
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ */
+static int
+luaA_class_gc(lua_State *L)
+{
+    lua_object_t *item = lua_touserdata(L, 1);
+    signal_array_wipe(&item->signals);
+    /* Get the object class */
+    lua_class_t *class = luaA_class_get(L, 1);
+    /* Call the collector function of the class, and all its parent classes */
+    for(; class; class = class->parent)
+        if(class->collector)
+            class->collector(item);
+    return 0;
+}
+
 /** Setup a new Lua class.
  * \param L The Lua VM state.
  * \param name The class name.
  * \param parent The parent class (inheritance).
  * \param allocator The allocator function used when creating a new object.
+ * \param Collector The collector function used when garbage collecting an
+ * object.
  * \param checker The check function to call when using luaA_checkudata().
  * \param index_miss_property Function to call when an object of this class
  * receive a __index request on an unknown property.
@@ -181,18 +201,19 @@ luaA_class_setup(lua_State *L, lua_class_t *class,
                  const char *name,
                  lua_class_t *parent,
                  lua_class_allocator_t allocator,
+                 lua_class_collector_t collector,
                  lua_class_checker_t checker,
                  lua_class_propfunc_t index_miss_property,
                  lua_class_propfunc_t newindex_miss_property,
                  const struct luaL_reg methods[],
                  const struct luaL_reg meta[])
 {
-    /* Create the metatable */
+    /* Create the object metatable */
     lua_newtable(L);
     /* Register it with class pointer as key in the registry
      * class-pointer -> metatable */
     lua_pushlightuserdata(L, class);
-    /* Duplicate the metatable */
+    /* Duplicate the object metatable */
     lua_pushvalue(L, -2);
     lua_rawset(L, LUA_REGISTRYINDEX);
     /* Now register class pointer with metatable as key in the registry
@@ -201,7 +222,12 @@ luaA_class_setup(lua_State *L, lua_class_t *class,
     lua_pushlightuserdata(L, class);
     lua_rawset(L, LUA_REGISTRYINDEX);
 
-    lua_pushvalue(L, -1);           /* dup metatable                      2 */
+    /* Duplicate objects metatable */
+    lua_pushvalue(L, -1);
+    /* Set garbage collector in the metatable */
+    lua_pushcfunction(L, luaA_class_gc);
+    lua_setfield(L, -2, "__gc");
+
     lua_setfield(L, -2, "__index"); /* metatable.__index = metatable      1 */
 
     luaL_register(L, NULL, meta);                                      /* 1 */
@@ -210,6 +236,7 @@ luaA_class_setup(lua_State *L, lua_class_t *class,
     lua_setmetatable(L, -2);        /* set self as metatable              2 */
     lua_pop(L, 2);
 
+    class->collector = collector;
     class->allocator = allocator;
     class->name = name;
     class->index_miss_property = index_miss_property;

common/luaclass.h

@@ -41,6 +41,7 @@ typedef struct
 } lua_object_t;
 
 typedef lua_object_t *(*lua_class_allocator_t)(lua_State *);
+typedef void (*lua_class_collector_t)(lua_object_t *);
 
 typedef int (*lua_class_propfunc_t)(lua_State *, lua_object_t *);
 
@@ -57,6 +58,8 @@ struct lua_class_t
     lua_class_t *parent;
     /** Allocator for creating new objects of that class */
     lua_class_allocator_t allocator;
+    /** Garbage collection function */
+    lua_class_collector_t collector;
     /** Class properties */
     lua_class_property_array_t properties;
     /** Function to call when a indexing an unknown property */
@@ -76,7 +79,8 @@ void luaA_class_emit_signal(lua_State *, lua_class_t *, const char *, int);
 
 void luaA_openlib(lua_State *, const char *, const struct luaL_reg[], const struct luaL_reg[]);
 void luaA_class_setup(lua_State *, lua_class_t *, const char *, lua_class_t *,
-                      lua_class_allocator_t, lua_class_checker_t,
+                      lua_class_allocator_t, lua_class_collector_t,
+                      lua_class_checker_t,
                       lua_class_propfunc_t, lua_class_propfunc_t,
                       const struct luaL_reg[], const struct luaL_reg[]);
 

common/luaobject.c

@@ -300,16 +300,4 @@ luaA_object_tostring(lua_State *L)
     return 1;
 }
 
-/** Garbage collect a Lua object.
- * \param L The Lua VM state.
- * \return The number of elements pushed on stack.
- */
-int
-luaA_object_gc(lua_State *L)
-{
-    lua_object_t *item = lua_touserdata(L, 1);
-    signal_array_wipe(&item->signals);
-    return 0;
-}
-
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80

common/luaobject.h

@@ -191,7 +191,6 @@ int luaA_object_emit_signal_simple(lua_State *);
     }
 
 int luaA_object_tostring(lua_State *);
-int luaA_object_gc(lua_State *);
 
 #define LUA_OBJECT_META(prefix) \
     { "__tostring", luaA_object_tostring }, \

objects/button.c

@@ -110,12 +110,11 @@ button_class_setup(lua_State *L)
     {
         LUA_OBJECT_META(button)
         LUA_CLASS_META
-        { "__gc", luaA_object_gc },
         { NULL, NULL }
     };
 
     luaA_class_setup(L, &button_class, "button", NULL,
-                     (lua_class_allocator_t) button_new, NULL,
+                     (lua_class_allocator_t) button_new, NULL, NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      button_methods, button_meta);
     luaA_class_add_property(&button_class, A_TK_BUTTON,

objects/client.c

@@ -38,10 +38,9 @@
  * \param L The Lua VM state.
  * \return The number of element pushed on stack.
  */
-static int
+static void
-luaA_client_gc(lua_State *L)
+client_wipe(client_t *c)
 {
-    client_t *c = luaA_checkudata(L, 1, &client_class);
     button_array_wipe(&c->buttons);
     key_array_wipe(&c->keys);
     xcb_get_wm_protocols_reply_wipe(&c->protocols);
@@ -52,7 +51,6 @@ luaA_client_gc(lua_State *L)
     p_delete(&c->alt_icon_name);
     p_delete(&c->name);
     p_delete(&c->alt_name);
-    return luaA_object_gc(L);
 }
 
 /** Change the clients urgency flag.
@@ -2031,12 +2029,12 @@ client_class_setup(lua_State *L)
         { "raise", luaA_client_raise },
         { "lower", luaA_client_lower },
         { "unmanage", luaA_client_unmanage },
-        { "__gc", luaA_client_gc },
         { NULL, NULL }
     };
 
     luaA_class_setup(L, &client_class, "client", &window_class,
                      (lua_class_allocator_t) client_new,
+                     (lua_class_collector_t) client_wipe,
                      (lua_class_checker_t) client_checker,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      client_methods, client_meta);

objects/image.c

@@ -42,14 +42,12 @@ struct image
 
 LUA_OBJECT_FUNCS(image_class, image_t, image)
 
-static int
+static void
-luaA_image_gc(lua_State *L)
+image_wipe(image_t *image)
 {
-    image_t *p = luaA_checkudata(L, 1, &image_class);
+    imlib_context_set_image(image->image);
-    imlib_context_set_image(p->image);
     imlib_free_image();
-    p_delete(&p->data);
+    p_delete(&image->data);
-    return luaA_object_gc(L);
 }
 
 static const char *
@@ -816,12 +814,13 @@ image_class_setup(lua_State *L)
         { "draw_rectangle", luaA_image_draw_rectangle },
         { "draw_rectangle_gradient", luaA_image_draw_rectangle_gradient },
         { "draw_circle", luaA_image_draw_circle },
-        { "__gc", luaA_image_gc },
         { NULL, NULL }
     };
 
     luaA_class_setup(L, &image_class, "image", NULL,
-                     (lua_class_allocator_t) image_new, NULL,
+                     (lua_class_allocator_t) image_new,
+                     (lua_class_collector_t) image_wipe,
+                     NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      image_methods, image_meta);
     luaA_class_add_property(&image_class, A_TK_WIDTH,

objects/key.c

@@ -1122,12 +1122,11 @@ key_class_setup(lua_State *L)
     {
         LUA_OBJECT_META(key)
         LUA_CLASS_META
-        { "__gc", luaA_object_gc },
         { NULL, NULL },
     };
 
     luaA_class_setup(L, &key_class, "key", NULL,
-                     (lua_class_allocator_t) key_new, NULL,
+                     (lua_class_allocator_t) key_new, NULL, NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      key_methods, key_meta);
     luaA_class_add_property(&key_class, A_TK_KEY,

objects/tag.c

@@ -50,17 +50,11 @@ tag_unref_simplified(tag_t **tag)
     luaA_object_unref(globalconf.L, *tag);
 }
 
-/** Garbage collect a tag.
+static void
- * \param L The Lua VM state.
+tag_wipe(tag_t *tag)
- * \return 0.
- */
-static int
-luaA_tag_gc(lua_State *L)
 {
-    tag_t *tag = luaA_checkudata(L, 1, &tag_class);
     client_array_wipe(&tag->clients);
     p_delete(&tag->name);
-    return luaA_object_gc(L);
 }
 
 OBJECT_EXPORT_PROPERTY(tag, tag_t, selected)
@@ -413,12 +407,13 @@ tag_class_setup(lua_State *L)
         LUA_OBJECT_META(tag)
         LUA_CLASS_META
         { "clients", luaA_tag_clients },
-        { "__gc", luaA_tag_gc },
         { NULL, NULL },
     };
 
     luaA_class_setup(L, &tag_class, "tag", NULL,
-                     (lua_class_allocator_t) tag_new, NULL,
+                     (lua_class_allocator_t) tag_new,
+                     (lua_class_collector_t) tag_wipe,
+                     NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      tag_methods, tag_meta);
     luaA_class_add_property(&tag_class, A_TK_NAME,

objects/timer.c

@@ -118,12 +118,11 @@ timer_class_setup(lua_State *L)
             LUA_CLASS_META
             { "start", luaA_timer_start },
             { "stop", luaA_timer_stop },
-            { "__gc", luaA_object_gc },
             { NULL, NULL },
     };
 
     luaA_class_setup(L, &timer_class, "timer", NULL,
-                     (lua_class_allocator_t) timer_new, NULL,
+                     (lua_class_allocator_t) timer_new, NULL, NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      timer_methods, timer_meta);
     luaA_class_add_property(&timer_class, A_TK_TIMEOUT,

objects/wibox.c

@@ -37,7 +37,7 @@ LUA_OBJECT_FUNCS(wibox_class, wibox_t, wibox)
  * \param w The wibox to wipe.
  */
 static void
-wibox_wipe(wibox_t *w)
+wibox_wipe_resources(wibox_t *w)
 {
     if(w->window)
     {
@@ -61,19 +61,13 @@ wibox_wipe(wibox_t *w)
     draw_context_wipe(&w->ctx);
 }
 
-/** Take care of garbage collecting a wibox.
+static void
- * \param L The Lua VM state.
+wibox_wipe(wibox_t *wibox)
- * \return The number of elements pushed on stack, 0!
- */
-static int
-luaA_wibox_gc(lua_State *L)
 {
-    wibox_t *wibox = luaA_checkudata(L, 1, &wibox_class);
     p_delete(&wibox->cursor);
-    wibox_wipe(wibox);
+    wibox_wipe_resources(wibox);
     button_array_wipe(&wibox->buttons);
     widget_node_array_wipe(&wibox->widgets);
-    return luaA_object_gc(L);
 }
 
 /** Wipe an array of widget_node. Release references to widgets.
@@ -702,7 +696,7 @@ wibox_detach(lua_State *L, int udx)
 
         wibox_clear_mouse_over(wibox);
 
-        wibox_wipe(wibox);
+        wibox_wipe_resources(wibox);
 
         foreach(item, globalconf.wiboxes)
             if(*item == wibox)
@@ -1318,12 +1312,13 @@ wibox_class_setup(lua_State *L)
         LUA_CLASS_META
         { "buttons", luaA_wibox_buttons },
         { "geometry", luaA_wibox_geometry },
-        { "__gc", luaA_wibox_gc },
         { NULL, NULL },
     };
 
     luaA_class_setup(L, &wibox_class, "wibox", &window_class,
-                     (lua_class_allocator_t) wibox_new, NULL,
+                     (lua_class_allocator_t) wibox_new,
+                     (lua_class_collector_t) wibox_wipe,
+                     NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      wibox_methods, wibox_meta);
     luaA_class_add_property(&wibox_class, A_TK_WIDGETS,

objects/widget.c

@@ -35,18 +35,12 @@
 
 LUA_OBJECT_FUNCS(widget_class, widget_t, widget);
 
-/** Collect a widget structure.
+static void
- * \param L The Lua VM state.
+widget_wipe(widget_t *widget)
- * \return 0
- */
-static int
-luaA_widget_gc(lua_State *L)
 {
-    widget_t *widget = luaA_checkudata(L, 1, &widget_class);
     if(widget->destructor)
         widget->destructor(widget);
     button_array_wipe(&widget->buttons);
-    return luaA_object_gc(L);
 }
 
 /** Get a widget node from a wibox by coords.
@@ -574,13 +568,13 @@ widget_class_setup(lua_State *L)
         { "extents", luaA_widget_extents },
         { "__index", luaA_widget_index },
         { "__newindex", luaA_widget_newindex },
-        { "__gc", luaA_widget_gc },
         { NULL, NULL }
     };
 
     luaA_class_setup(L, &widget_class, "widget", NULL,
-                     (lua_class_allocator_t) widget_new, NULL,
+                     (lua_class_allocator_t) widget_new,
-                     NULL, NULL,
+                     (lua_class_collector_t) widget_wipe,
+                     NULL, NULL, NULL,
                      widget_methods, widget_meta);
     luaA_class_add_property(&widget_class, A_TK_VISIBLE,
                             (lua_class_propfunc_t) luaA_widget_set_visible,

objects/window.c

@@ -119,7 +119,7 @@ window_class_setup(lua_State *L)
     };
 
     luaA_class_setup(L, &window_class, "window", NULL,
-                     NULL, NULL,
+                     NULL, NULL, NULL,
                      luaA_class_index_miss_property, luaA_class_newindex_miss_property,
                      window_methods, window_meta);