From a422ae022bf95b9eeebeaa6ceafcb0f589499bfd Mon Sep 17 00:00:00 2001
From: Robert Mader <robert.mader@collabora.com>
Date: Fri, 2 Feb 2024 17:52:27 +0100
Subject: [PATCH] wayland/buffer: Move scanout lifetime handling

There doesn't seem to be a good reason to keep this code in
`MetaWaylandSurface`. Moving it to `MetaWaylandBuffer` cleans things
up and will allow us to tread buffers differently depending on their
type.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3559>
---
 src/wayland/meta-wayland-buffer.c  | 22 +++++++++++++++++++---
 src/wayland/meta-wayland-surface.c | 25 ++-----------------------
 2 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/src/wayland/meta-wayland-buffer.c b/src/wayland/meta-wayland-buffer.c
index 6837ee1ca..be7039c2e 100644
--- a/src/wayland/meta-wayland-buffer.c
+++ b/src/wayland/meta-wayland-buffer.c
@@ -897,6 +897,16 @@ try_acquire_egl_image_scanout (MetaWaylandBuffer *buffer,
 #endif
 }
 
+static void
+scanout_destroyed (gpointer  data,
+                   GObject  *where_the_object_was)
+{
+  MetaWaylandBuffer *buffer = data;
+
+  meta_wayland_buffer_dec_use_count (buffer);
+  g_object_unref (buffer);
+}
+
 CoglScanout *
 meta_wayland_buffer_try_acquire_scanout (MetaWaylandBuffer *buffer,
                                          CoglOnscreen      *onscreen)
@@ -936,9 +946,15 @@ meta_wayland_buffer_try_acquire_scanout (MetaWaylandBuffer *buffer,
       return NULL;
     }
 
-  if (scanout)
-    g_signal_connect (scanout, "scanout-failed",
-                      G_CALLBACK (on_scanout_failed), buffer);
+  if (!scanout)
+    return NULL;
+
+  g_signal_connect (scanout, "scanout-failed",
+                    G_CALLBACK (on_scanout_failed), buffer);
+
+  g_object_ref (buffer);
+  meta_wayland_buffer_inc_use_count (buffer);
+  g_object_weak_ref (G_OBJECT (scanout), scanout_destroyed, buffer);
 
   return scanout;
 }
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index d31791bb9..213bccd64 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -2253,39 +2253,18 @@ meta_wayland_surface_get_buffer_height (MetaWaylandSurface *surface)
     return 0;
 }
 
-static void
-scanout_destroyed (gpointer  data,
-                   GObject  *where_the_object_was)
-{
-  MetaWaylandBuffer *buffer = data;
-
-  meta_wayland_buffer_dec_use_count (buffer);
-  g_object_unref (buffer);
-}
-
 CoglScanout *
 meta_wayland_surface_try_acquire_scanout (MetaWaylandSurface *surface,
                                           CoglOnscreen       *onscreen)
 {
-  CoglScanout *scanout;
-  MetaWaylandBuffer *buffer;
-
   if (!surface->buffer)
     return NULL;
 
   if (surface->buffer->use_count == 0)
     return NULL;
 
-  scanout = meta_wayland_buffer_try_acquire_scanout (surface->buffer,
-                                                     onscreen);
-  if (!scanout)
-    return NULL;
-
-  buffer = g_object_ref (surface->buffer);
-  meta_wayland_buffer_inc_use_count (buffer);
-  g_object_weak_ref (G_OBJECT (scanout), scanout_destroyed, buffer);
-
-  return scanout;
+  return meta_wayland_buffer_try_acquire_scanout (surface->buffer,
+                                                  onscreen);
 }
 
 MetaCrtc *