naughty: Never hold a strong reference to the notification in the box.

luajit was failing to GC the notification about 5% of the time. This
commit stores all widget notifications in a weak table and don't let
any lambda access the parent object notification object.

Each of those changes reduces the failure rate. There might still be
a couple in there, but the test passed 200x on my laptop with 100%
success rate.

lib/naughty/container/background.lua

@@ -46,22 +46,24 @@ end
 -- @propemits true false
 
 function background:set_notification(notif)
-    if self._private.notification == notif then return end
+    local old = self._private.notification[1]
 
-    if self._private.notification then
+    if old == notif then return end
-        self._private.notification:disconnect_signal("property::bg",
+
+    if old then
+        old:disconnect_signal("property::bg",
             self._private.background_changed_callback)
-        self._private.notification:disconnect_signal("property::border_width",
+        old:disconnect_signal("property::border_width",
             self._private.background_changed_callback)
-        self._private.notification:disconnect_signal("property::border_color",
+        old:disconnect_signal("property::border_color",
             self._private.background_changed_callback)
-        self._private.notification:disconnect_signal("property::shape",
+        old:disconnect_signal("property::shape",
             self._private.background_changed_callback)
     end
 
     update_background(notif, self)
 
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
 
     notif:connect_signal("property::bg"          , self._private.background_changed_callback)
     notif:connect_signal("property::border_width", self._private.background_changed_callback)
@@ -82,12 +84,13 @@ local function new(args)
     args = args or {}
 
     local bg = wbg()
+    bg._private.notification = {}
     bg:set_border_strategy("inner")
 
     gtable.crush(bg, background, true)
 
     function bg._private.background_changed_callback()
-        update_background(bg._private.notification, bg)
+        update_background(bg._private.notification[1], bg)
     end
 
     if args.notification then

lib/naughty/layout/box.lua

@@ -47,14 +47,16 @@ local function init_screen(s)
 end
 
 local function disconnect(self)
-    if self._private.notification then
+    local n = self._private.notification[1]
-        self._private.notification:disconnect_signal("destroyed",
+
+    if n then
+        n:disconnect_signal("destroyed",
             self._private.destroy_callback)
 
-        self._private.notification:disconnect_signal("property::margin",
+        n:disconnect_signal("property::margin",
             self._private.update)
 
-        self._private.notification:disconnect_signal("property::suspended",
+        n:disconnect_signal("property::suspended",
             self._private.hide)
     end
 end
@@ -123,14 +125,13 @@ local function finish(self)
         end
     end
 
-    local preset
+    local preset = (self._private.notification[1] or {}).preset
-    if self.private and self.private.args and self.private.args.notification then
-        preset = self.private.args.notification.preset
-    end
 
     update_position(self.position, preset)
 
     disconnect(self)
+
+    self._private.notification = {}
 end
 
 -- It isn't a good idea to use the `attach` `awful.placement` property. If the
@@ -236,21 +237,19 @@ local function generate_widget(args, n)
     end
 
     -- Call `:set_notification` on all children
-    awcommon._set_common_property(w, "notification", n or args.notification)
+    awcommon._set_common_property(w, "notification", n)
 
     return w
 end
 
 local function init(self, notification)
-    local args = self._private.args
-
     local preset = notification.preset or {}
 
-    local position = args.position or notification.position or
+    local position = self._private.position or notification.position or
         preset.position or beautiful.notification_position or "top_right"
 
     if not self.widget then
-        self.widget = generate_widget(self._private.args, notification)
+        self.widget = generate_widget(self._private, notification)
     end
 
     local bg = self._private.widget:get_children_by_id( "background_role" )[1]
@@ -295,20 +294,26 @@ local function init(self, notification)
 end
 
 function box:set_notification(notif)
-    if self._private.notification == notif then return end
+    if self._private.notification[1] == notif then return end
 
     disconnect(self)
 
     init(self, notif)
 
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
 
     self:emit_signal("property::notification", notif)
 end
 
+function box:get_notification()
+    return self._private.notification[1]
+end
+
 function box:get_position()
-    if self._private.notification then
+    local n = self._private.notification[1]
-        return self._private.notification:get_position()
+
+    if n then
+        return n:get_position()
     end
 
     return "top_right"
@@ -357,7 +362,9 @@ local function new(args)
     if not new_args.widget then return nil end
 
     local ret = popup(new_args)
-    ret._private.args = new_args
+    ret._private.notification = {}
+    ret._private.widget_template = args.widget_template
+    ret._private.position = args.position
 
     gtable.crush(ret, box, true)
 
@@ -371,8 +378,10 @@ local function new(args)
 
     --TODO remove
     local function hide()
-        if ret._private.notification then
+        local n = ret._private.notification[1]
-            ret._private.notification:destroy()
+
+        if n then
+            n:destroy()
         end
     end
 

lib/naughty/list/actions.lua

@@ -168,14 +168,16 @@ local function wb_label(action, self)
 end
 
 local function update(self)
-    if not self._private.layout or not self._private.notification then return end
+    local n = self._private.notification[1]
+
+    if not self._private.layout or not n then return end
 
     awcommon.list_update(
         self._private.layout,
         self._private.default_buttons,
         function(o) return wb_label(o, self) end,
         self._private.data,
-        self._private.notification.actions,
+        n.actions,
         {
             widget_template = self._private.widget_template
         }
@@ -229,7 +231,7 @@ local actionlist = {}
 
 
 function actionlist:set_notification(notif)
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
 
     if not self._private.layout then
         self._private.layout = wibox.layout.fixed.horizontal()
@@ -329,8 +331,9 @@ local function new(_, args)
     gtable.crush(wdg, actionlist, true)
 
     wdg._private.data = {}
+    wdg._private.notification = {}
 
-    gtable.crush(wdg, args)
+    gtable.crush(wdg, args, false)
 
     wdg._private.style = wdg._private.style or {}
 
@@ -338,7 +341,7 @@ local function new(_, args)
 
     wdg._private.default_buttons = gtable.join(
         abutton({ }, 1, function(a)
-            local notif = wdg._private.notification or args.notification
+            local notif = wdg._private.notification[1]
             a:invoke(notif)
         end)
     )

lib/naughty/widget/_default.lua

@@ -22,7 +22,7 @@ local function notif_size()
     constraint:set_width(beautiful.notification_max_width or dpi(500))
 
     rawset(constraint, "set_notification", function(_, notif)
-        constraint._private.notification = notif
+        constraint._private.notification = setmetatable({notif}, {__mode = "v"})
         local s = false
 
         if notif.width and notif.width ~= beautiful.notification_max_width then
@@ -37,6 +37,10 @@ local function notif_size()
         constraint.strategy = s and "exact" or "max"
     end)
 
+    rawset(constraint, "get_notification", function()
+        return constraint._private.notification[1]
+    end)
+
     return constraint
 end
 

lib/naughty/widget/icon.lua

@@ -83,10 +83,12 @@ end
 -- @propemits true false
 
 function icon:set_notification(notif)
-    if self._private.notification == notif then return end
+    local old = (self._private.notification or {})[1]
 
-    if self._private.notification then
+    if old == notif then return end
-        self._private.notification:disconnect_signal("destroyed",
+
+    if old then
+        old:disconnect_signal("destroyed",
             self._private.icon_changed_callback)
     end
 
@@ -96,7 +98,7 @@ function icon:set_notification(notif)
         self:set_image(icn)
     end
 
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
 
     notif:connect_signal("property::icon", self._private.icon_changed_callback)
     self:emit_signal("property::notification", notif)
@@ -154,10 +156,14 @@ local function new(args)
     local tb = imagebox()
 
     gtable.crush(tb, icon, true)
+    tb._private.notification = {}
 
     function tb._private.icon_changed_callback()
+        local n = tb._private.notification[1]
 
-        local icn = gsurface.load_silently(tb._private.notification.icon)
+        if not n then return end
+
+        local icn = gsurface.load_silently(n.icon)
 
         if icn then
             tb:set_image(icn)

lib/naughty/widget/message.lua

@@ -27,18 +27,20 @@ local message = {}
 -- @propemits true false
 
 function message:set_notification(notif)
-    if self._private.notification == notif then return end
+    local old = self._private.notification[1]
 
-    if self._private.notification then
+    if old == notif then return end
-        self._private.notification:disconnect_signal("property::message",
+
+    if old then
+        old:disconnect_signal("property::message",
             self._private.message_changed_callback)
-        self._private.notification:disconnect_signal("property::fg",
+        old:disconnect_signal("property::fg",
             self._private.message_changed_callback)
     end
 
     markup(self, notif.message, notif.fg, notif.font)
 
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
 
     notif:connect_signal("property::message", self._private.message_changed_callback)
     notif:connect_signal("property::fg"     , self._private.message_changed_callback)
@@ -57,16 +59,23 @@ local function new(args)
     local tb = textbox()
     tb:set_wrap("word")
     tb:set_font(beautiful.notification_font)
+    tb._private.notification = {}
 
     gtable.crush(tb, message, true)
 
     function tb._private.message_changed_callback()
+        local n = tb._private.notification[1]
+
+        if n then
             markup(
                 tb,
-            tb._private.notification.message,
+                n.message,
-            tb._private.notification.fg,
+                n.fg,
-            tb._private.notification.font
+                n.font
             )
+        else
+            markup(tb, nil, nil)
+        end
     end
 
     if args.notification then

lib/naughty/widget/title.lua

@@ -27,18 +27,20 @@ local title = {}
 -- @propemits true false
 
 function title:set_notification(notif)
-    if self._private.notification == notif then return end
+    local old = self._private.notification[1]
 
-    if self._private.notification then
+    if old == notif then return end
-        self._private.notification:disconnect_signal("property::message",
+
+    if old then
+        old:disconnect_signal("property::message",
             self._private.title_changed_callback)
-        self._private.notification:disconnect_signal("property::fg",
+        old:disconnect_signal("property::fg",
             self._private.title_changed_callback)
     end
 
     markup(self, notif.title, notif.fg, notif.font)
 
-    self._private.notification = notif
+    self._private.notification = setmetatable({notif}, {__mode="v"})
     self._private.title_changed_callback()
 
     notif:connect_signal("property::title", self._private.title_changed_callback)
@@ -58,16 +60,23 @@ local function new(args)
     local tb = textbox()
     tb:set_wrap("word")
     tb:set_font(beautiful.notification_font)
+    tb._private.notification = {}
 
     gtable.crush(tb, title, true)
 
     function tb._private.title_changed_callback()
+        local n = tb._private.notification[1]
+
+        if n then
             markup(
                 tb,
-            tb._private.notification.title,
+                n.title,
-            tb._private.notification.fg,
+                n.fg,
-            tb._private.notification.font
+                n.font
             )
+        else
+            markup("", nil, nil)
+        end
     end
 
     if args.notification then