xlib: Remove reference counting for cairo_xlib_screen_t

The screen is owned by the cairo_xlib_display_t device, so we can
simplify and close the refleak by removing the surplus reference
counting.

5 files changed, 46 insertions, 147 deletions

diff --git a/src/cairo-xlib-display.c b/src/cairo-xlib-display.c
index afa75327..a86c2062 100644
--- a/src/cairo-xlib-display.c
+++ b/src/cairo-xlib-display.c
@@ -73,10 +73,10 @@ _cairo_xlib_remove_close_display_hook_internal (cairo_xlib_display_t *display,
 static void
 _cairo_xlib_call_close_display_hooks (cairo_xlib_display_t *display)
 {
-    cairo_xlib_screen_t	    *screen;
-    cairo_xlib_hook_t		    *hook;
+    cairo_xlib_screen_t *screen;
+    cairo_xlib_hook_t *hook;
 
-    for (screen = display->screens; screen != NULL; screen = screen->next)
+    cairo_list_foreach_entry (screen, cairo_xlib_screen_t, &display->screens, link)
 	_cairo_xlib_screen_close_display (display, screen);
 
     while (TRUE) {
@@ -92,22 +92,6 @@ _cairo_xlib_call_close_display_hooks (cairo_xlib_display_t *display)
 }
 
 static void
-_cairo_xlib_display_discard_screens (cairo_xlib_display_t *display)
-{
-    cairo_xlib_screen_t *screens;
-
-    screens = display->screens;
-    display->screens = NULL;
-
-    while (screens != NULL) {
-	cairo_xlib_screen_t *screen = screens;
-	screens = screen->next;
-
-	_cairo_xlib_screen_destroy (screen);
-    }
-}
-
-static void
 _cairo_xlib_display_finish (void *abstract_display)
 {
     cairo_xlib_display_t *display = abstract_display;
@@ -132,6 +116,12 @@ _cairo_xlib_display_destroy (void *abstract_display)
     }
     _cairo_freelist_fini (&display->wq_freelist);
 
+    while (! cairo_list_is_empty (&display->screens)) {
+	_cairo_xlib_screen_destroy (cairo_list_first_entry (&display->screens,
+                                                            cairo_xlib_screen_t,
+                                                            link));
+    }
+
     free (display);
 }
 
@@ -216,7 +206,6 @@ _cairo_xlib_close_display (Display *dpy, XExtCodes *codes)
 
       _cairo_xlib_display_notify (display);
       _cairo_xlib_call_close_display_hooks (display);
-      _cairo_xlib_display_discard_screens (display);
 
       /* catch any that arrived before marking the display as closed */
       _cairo_xlib_display_notify (display);
@@ -353,7 +342,7 @@ _cairo_xlib_device_create (Display *dpy)
 
     cairo_device_reference (&display->base); /* add one for the CloseDisplay */
     display->display = dpy;
-    display->screens = NULL;
+    cairo_list_init (&display->screens);
     display->workqueue = NULL;
     display->close_display_hooks = NULL;
     display->closed = FALSE;
@@ -610,56 +599,21 @@ _cairo_xlib_display_get_xrender_format (cairo_xlib_display_t	*display,
     return xrender_format;
 }
 
-void
-_cairo_xlib_display_remove_screen (cairo_xlib_display_t *display,
-				   cairo_xlib_screen_t *screen)
-{
-    cairo_xlib_screen_t **prev;
-    cairo_xlib_screen_t *list;
-
-    for (prev = &display->screens; (list = *prev); prev = &list->next) {
-	if (list == screen) {
-	    *prev = screen->next;
-	    break;
-	}
-    }
-}
-
-cairo_status_t
+cairo_xlib_screen_t *
 _cairo_xlib_display_get_screen (cairo_xlib_display_t *display,
-				Screen *screen,
-				cairo_xlib_screen_t **out)
+				Screen *screen)
 {
-    cairo_xlib_screen_t *info = NULL, **prev;
-
-    if (display->closed)
-	return _cairo_error (CAIRO_STATUS_SURFACE_FINISHED);
+    cairo_xlib_screen_t *info;
 
-    for (prev = &display->screens; (info = *prev); prev = &(*prev)->next) {
+    cairo_list_foreach_entry (info, cairo_xlib_screen_t, &display->screens, link) {
 	if (info->screen == screen) {
-	    /*
-	     * MRU the list
-	     */
-	    if (prev != &display->screens) {
-		*prev = info->next;
-		info->next = display->screens;
-		display->screens = info;
-	    }
-	    break;
-	}
+            if (display->screens.next != &info->link)
+                cairo_list_move (&info->link, &display->screens);
+            return info;
+        }
     }
 
-    *out = info;
-    return CAIRO_STATUS_SUCCESS;
-}
-
-
-void
-_cairo_xlib_display_add_screen (cairo_xlib_display_t *display,
-				cairo_xlib_screen_t *screen)
-{
-    screen->next = display->screens;
-    display->screens = screen;
+    return NULL;
 }
 
 void
diff --git a/src/cairo-xlib-private.h b/src/cairo-xlib-private.h
index 345f3e13..24bf5e32 100644
--- a/src/cairo-xlib-private.h
+++ b/src/cairo-xlib-private.h
@@ -71,7 +71,7 @@ struct _cairo_xlib_display {
     cairo_xlib_display_t *next;
 
     Display *display;
-    cairo_xlib_screen_t *screens;
+    cairo_list_t screens;
 
     int render_major;
     int render_minor;
@@ -98,8 +98,7 @@ typedef struct _cairo_xlib_visual_info {
 } cairo_xlib_visual_info_t;
 
 struct _cairo_xlib_screen {
-    cairo_xlib_screen_t *next;
-    cairo_reference_count_t ref_count;
+    cairo_list_t link;
 
     cairo_device_t *device;
     Screen *screen;
@@ -116,18 +115,9 @@ struct _cairo_xlib_screen {
 cairo_private cairo_device_t *
 _cairo_xlib_device_create (Display *display);
 
-cairo_private void
-_cairo_xlib_display_add_screen (cairo_xlib_display_t *display,
-				cairo_xlib_screen_t *screen);
-
-cairo_private cairo_status_t
+cairo_private cairo_xlib_screen_t *
 _cairo_xlib_display_get_screen (cairo_xlib_display_t *display,
-				Screen *screen,
-				cairo_xlib_screen_t **out);
-
-cairo_private void
-_cairo_xlib_display_remove_screen (cairo_xlib_display_t *display,
-				   cairo_xlib_screen_t *screen);
+				Screen *screen);
 
 cairo_private void
 _cairo_xlib_add_close_display_hook (cairo_xlib_display_t *display, cairo_xlib_hook_t *hook);
@@ -170,8 +160,6 @@ _cairo_xlib_screen_get (Display *dpy,
 			Screen *screen,
 			cairo_xlib_screen_t **out);
 
-cairo_private cairo_xlib_screen_t *
-_cairo_xlib_screen_reference (cairo_xlib_screen_t *info);
 cairo_private void
 _cairo_xlib_screen_destroy (cairo_xlib_screen_t *info);
 
@@ -207,6 +195,6 @@ _cairo_xlib_visual_info_create (Display *dpy,
 				cairo_xlib_visual_info_t **out);
 
 cairo_private void
-_cairo_xlib_visual_info_destroy (Display *dpy, cairo_xlib_visual_info_t *info);
+_cairo_xlib_visual_info_destroy (cairo_xlib_visual_info_t *info);
 
 #endif /* CAIRO_XLIB_PRIVATE_H */
diff --git a/src/cairo-xlib-screen.c b/src/cairo-xlib-screen.c
index d1d9cf6c..b094eaf4 100644
--- a/src/cairo-xlib-screen.c
+++ b/src/cairo-xlib-screen.c
@@ -256,16 +256,6 @@ _cairo_xlib_init_screen_font_options (Display *dpy,
     cairo_font_options_set_hint_metrics (&info->font_options, CAIRO_HINT_METRICS_ON);
 }
 
-cairo_xlib_screen_t *
-_cairo_xlib_screen_reference (cairo_xlib_screen_t *info)
-{
-    assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&info->ref_count));
-
-    _cairo_reference_count_inc (&info->ref_count);
-
-    return info;
-}
-
 void
 _cairo_xlib_screen_close_display (cairo_xlib_display_t *display,
                                   cairo_xlib_screen_t  *info)
@@ -274,37 +264,25 @@ _cairo_xlib_screen_close_display (cairo_xlib_display_t *display,
     int i;
 
     dpy = display->display;
+
     for (i = 0; i < ARRAY_LENGTH (info->gc); i++) {
 	if ((info->gc_depths >> (8*i)) & 0xff)
 	    XFreeGC (dpy, info->gc[i]);
     }
     info->gc_depths = 0;
-
-    while (! cairo_list_is_empty (&info->visuals)) {
-        _cairo_xlib_visual_info_destroy (dpy,
-                                         cairo_list_first_entry (&info->visuals,
-                                                                 cairo_xlib_visual_info_t,
-                                                                 link));
-    }
 }
 
 void
 _cairo_xlib_screen_destroy (cairo_xlib_screen_t *info)
 {
-    cairo_xlib_display_t *display;
-
-    assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&info->ref_count));
-
-    if (! _cairo_reference_count_dec_and_test (&info->ref_count))
-	return;
-
-    if (! _cairo_xlib_display_acquire (info->device, &display)) {
-        _cairo_xlib_display_remove_screen (display, info);
-        _cairo_xlib_screen_close_display (display, info);
-
-        cairo_device_release (&display->base);
+    while (! cairo_list_is_empty (&info->visuals)) {
+        _cairo_xlib_visual_info_destroy (cairo_list_first_entry (&info->visuals,
+                                                                 cairo_xlib_visual_info_t,
+                                                                 link));
     }
 
+    cairo_list_del (&info->link);
+
     free (info);
 }
 
@@ -327,12 +305,9 @@ _cairo_xlib_screen_get (Display *dpy,
     if (unlikely (status))
         goto CLEANUP_DEVICE;
 
-    status = _cairo_xlib_display_get_screen (display, screen, &info);
-    if (unlikely (status))
-	goto CLEANUP_DISPLAY;
-
+    info = _cairo_xlib_display_get_screen (display, screen);
     if (info != NULL) {
-	*out = _cairo_xlib_screen_reference (info);
+	*out = info;
 	goto CLEANUP_DISPLAY;
     }
 
@@ -342,7 +317,6 @@ _cairo_xlib_screen_get (Display *dpy,
 	goto CLEANUP_DISPLAY;
     }
 
-    CAIRO_REFERENCE_COUNT_INIT (&info->ref_count, 2); /* Add one for display cache */
     info->device = device;
     info->screen = screen;
     info->has_font_options = FALSE;
@@ -350,8 +324,7 @@ _cairo_xlib_screen_get (Display *dpy,
     memset (info->gc, 0, sizeof (info->gc));
 
     cairo_list_init (&info->visuals);
-
-    _cairo_xlib_display_add_screen (display, info);
+    cairo_list_add (&info->link, &display->screens);
 
     *out = info;
 
diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c
index fa7d6452..3b01fdeb 100644
--- a/src/cairo-xlib-surface.c
+++ b/src/cairo-xlib-surface.c
@@ -415,8 +415,6 @@ _cairo_xlib_surface_finish (void *abstract_surface)
 
     cairo_device_release (&display->base);
 
-    _cairo_xlib_screen_destroy (surface->screen);
-
     cairo_region_destroy (surface->clip_region);
 
     return status;
@@ -2947,8 +2945,6 @@ _cairo_xlib_surface_create_internal (cairo_xlib_screen_t	*screen,
     cairo_xlib_surface_t *surface;
     cairo_xlib_display_t *display;
     cairo_status_t status;
-      
-    CAIRO_MUTEX_INITIALIZE ();
 
     if (depth == 0) {
 	if (xrender_format) {
@@ -3019,7 +3015,7 @@ found:
     surface->close_display_hook.func = _cairo_xlib_surface_detach_display;
     _cairo_xlib_add_close_display_hook (display,
 					&surface->close_display_hook);
-    
+
     cairo_device_release (&display->base);
 
     _cairo_surface_init (&surface->base,
@@ -3027,7 +3023,7 @@ found:
 			 screen->device,
 			 _xrender_format_to_content (xrender_format));
 
-    surface->screen = _cairo_xlib_screen_reference (screen);
+    surface->screen = screen;
 
     surface->drawable = drawable;
     surface->owns_pixmap = FALSE;
@@ -3161,7 +3157,6 @@ cairo_xlib_surface_create (Display     *dpy,
 {
     Screen *scr;
     cairo_xlib_screen_t *screen;
-    cairo_surface_t *surface;
     cairo_status_t status;
 
     if (width > XLIB_COORD_MAX || height > XLIB_COORD_MAX) {
@@ -3179,12 +3174,9 @@ cairo_xlib_surface_create (Display     *dpy,
 
     X_DEBUG ((dpy, "create (drawable=%x)", (unsigned int) drawable));
 
-    surface = _cairo_xlib_surface_create_internal (screen, drawable,
-						   visual, NULL,
-						   width, height, 0);
-    _cairo_xlib_screen_destroy (screen);
-
-    return surface;
+    return _cairo_xlib_surface_create_internal (screen, drawable,
+                                                visual, NULL,
+                                                width, height, 0);
 }
 slim_hidden_def (cairo_xlib_surface_create);
 
@@ -3209,7 +3201,6 @@ cairo_xlib_surface_create_for_bitmap (Display  *dpy,
 				      int	height)
 {
     cairo_xlib_screen_t *screen;
-    cairo_surface_t *surface;
     cairo_status_t status;
 
     if (width > XLIB_COORD_MAX || height > XLIB_COORD_MAX)
@@ -3221,12 +3212,9 @@ cairo_xlib_surface_create_for_bitmap (Display  *dpy,
 
     X_DEBUG ((dpy, "create_for_bitmap (drawable=%x)", (unsigned int) bitmap));
 
-    surface = _cairo_xlib_surface_create_internal (screen, bitmap,
-						   NULL, NULL,
-						   width, height, 1);
-    _cairo_xlib_screen_destroy (screen);
-
-    return surface;
+    return _cairo_xlib_surface_create_internal (screen, bitmap,
+                                                NULL, NULL,
+                                                width, height, 1);
 }
 
 #if CAIRO_HAS_XLIB_XRENDER_SURFACE
@@ -3259,7 +3247,6 @@ cairo_xlib_surface_create_with_xrender_format (Display		    *dpy,
 					       int		    height)
 {
     cairo_xlib_screen_t *screen;
-    cairo_surface_t *surface;
     cairo_status_t status;
 
     if (width > XLIB_COORD_MAX || height > XLIB_COORD_MAX)
@@ -3271,12 +3258,9 @@ cairo_xlib_surface_create_with_xrender_format (Display		    *dpy,
 
     X_DEBUG ((dpy, "create_with_xrender_format (drawable=%x)", (unsigned int) drawable));
 
-    surface = _cairo_xlib_surface_create_internal (screen, drawable,
-						   NULL, format,
-						   width, height, 0);
-    _cairo_xlib_screen_destroy (screen);
-
-    return surface;
+    return _cairo_xlib_surface_create_internal (screen, drawable,
+                                                NULL, format,
+                                                width, height, 0);
 }
 slim_hidden_def (cairo_xlib_surface_create_with_xrender_format);
 
diff --git a/src/cairo-xlib-visual.c b/src/cairo-xlib-visual.c
index a76bf357..e076ed01 100644
--- a/src/cairo-xlib-visual.c
+++ b/src/cairo-xlib-visual.c
@@ -180,7 +180,7 @@ _cairo_xlib_visual_info_create (Display *dpy,
 }
 
 void
-_cairo_xlib_visual_info_destroy (Display *dpy, cairo_xlib_visual_info_t *info)
+_cairo_xlib_visual_info_destroy (cairo_xlib_visual_info_t *info)
 {
     /* No need for XFreeColors() whilst using DefaultColormap */
     free (info);