drm-buffer: Don't always generate fb_id on construction

It might not be needed by the user of the buffer, so don't always
require it up front. Instead make sure that any user that needs it first
calls "meta_drm_buffer_ensure_fb_id()" to create the ID.

Only the plain gbm implementation creates the ID lazilly, the other
still does it on construction due to the objects used to create them
only existing during construction.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1854>

1 files changed, 15 insertions, 3 deletions

diff --git a/src/backends/native/meta-drm-buffer.c b/src/backends/native/meta-drm-buffer.c
index 09e07b61d..c526263f7 100644
--- a/src/backends/native/meta-drm-buffer.c
+++ b/src/backends/native/meta-drm-buffer.c
@@ -67,9 +67,21 @@ meta_drm_buffer_get_device_file (MetaDrmBuffer *buffer)
 }
 
 gboolean
-meta_drm_buffer_ensure_fb_id (MetaDrmBuffer        *buffer,
-                              const MetaDrmFbArgs  *fb_args,
-                              GError              **error)
+meta_drm_buffer_ensure_fb_id (MetaDrmBuffer  *buffer,
+                              GError        **error)
+{
+  MetaDrmBufferPrivate *priv = meta_drm_buffer_get_instance_private (buffer);
+
+  if (priv->fb_id)
+    return TRUE;
+
+  return META_DRM_BUFFER_GET_CLASS (buffer)->ensure_fb_id (buffer, error);
+}
+
+gboolean
+meta_drm_buffer_do_ensure_fb_id (MetaDrmBuffer        *buffer,
+                                 const MetaDrmFbArgs  *fb_args,
+                                 GError              **error)
 {
   MetaDrmBufferPrivate *priv = meta_drm_buffer_get_instance_private (buffer);
   int fd;