From ff0045b8c90ae1adba10d7c453ae1fbbef744eae Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Tue, 17 Sep 2024 08:34:54 +0200
Subject: [PATCH] dmabuftexture: Stop having a fixed downloader

Change things from picking a download method at creation time to
trying all methods at download time until one succeeds.
---
 gdk/gdkdmabuftexture.c | 90 +++++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 41 deletions(-)

diff --git a/gdk/gdkdmabuftexture.c b/gdk/gdkdmabuftexture.c
index e68341db71..9858f25ce5 100644
--- a/gdk/gdkdmabuftexture.c
+++ b/gdk/gdkdmabuftexture.c
@@ -50,7 +50,6 @@ struct _GdkDmabufTexture
   GdkTexture parent_instance;
 
   GdkDisplay *display;
-  GdkDmabufDownloader *downloader;
 
   GdkDmabuf dmabuf;
 
@@ -85,7 +84,6 @@ gdk_dmabuf_texture_dispose (GObject *object)
       self->destroy = NULL;
     }
 
-  g_clear_object (&self->downloader);
   g_clear_object (&self->display);
 
   G_OBJECT_CLASS (gdk_dmabuf_texture_parent_class)->dispose (object);
@@ -107,16 +105,49 @@ static gboolean
 gdk_dmabuf_texture_invoke_callback (gpointer data)
 {
   Download *download = data;
+  GdkDisplay *display = download->texture->display;
 
-  gdk_dmabuf_downloader_download (download->texture->downloader,
-                                  download->texture,
-                                  download->format,
-                                  download->color_state,
-                                  download->data,
-                                  download->stride);
+  if (display->egl_downloader &&
+      gdk_dmabuf_downloader_download (display->egl_downloader,
+                                      download->texture,
+                                      download->format,
+                                      download->color_state,
+                                      download->data,
+                                      download->stride))
+    {
+      /* Successfully downloaded using EGL */
+    }
+  else if (display->vk_downloader &&
+           gdk_dmabuf_downloader_download (display->vk_downloader,
+                                           download->texture,
+                                           download->format,
+                                           download->color_state,
+                                           download->data,
+                                           download->stride))
+    {
+      /* Successfully downloaded using Vulkan */
+    }
+#ifdef HAVE_DMABUF
+  else if (gdk_dmabuf_download_mmap (GDK_TEXTURE (download->texture),
+                                     download->format,
+                                     download->color_state,
+                                     download->data,
+                                     download->stride))
+    {
+      /* Successfully downloaded using mmap */
+    }
+#endif
+  else
+    {
+      const GdkDmabuf *dmabuf = gdk_dmabuf_texture_get_dmabuf (download->texture);
+
+      g_critical ("Failed to download %dx%d dmabuf texture (format %.4s:%#" G_GINT64_MODIFIER "x)",
+                  gdk_texture_get_width (GDK_TEXTURE (download->texture)),
+                  gdk_texture_get_height (GDK_TEXTURE (download->texture)),
+                  (char *)&(dmabuf->fourcc), dmabuf->modifier);
+    }
 
   g_atomic_int_set (&download->spinlock, 1);
-
   return FALSE;
 }
 
@@ -130,14 +161,6 @@ gdk_dmabuf_texture_download (GdkTexture      *texture,
   GdkDmabufTexture *self = GDK_DMABUF_TEXTURE (texture);
   Download download = { self, format, color_state, data, stride, 0 };
 
-  if (self->downloader == NULL)
-    {
-#ifdef HAVE_DMABUF
-      gdk_dmabuf_download_mmap (texture, format, color_state, data, stride);
-#endif
-      return;
-    }
-
   g_main_context_invoke (NULL, gdk_dmabuf_texture_invoke_callback, &download);
 
   while (g_atomic_int_get (&download.spinlock) == 0);
@@ -232,37 +255,22 @@ gdk_dmabuf_texture_new_from_builder (GdkDmabufTextureBuilder *builder,
                                                  : GDK_MEMORY_R8G8B8A8;
     }
 
-  if (display->egl_downloader)
+  if (!gdk_dmabuf_formats_contains (display->dmabuf_formats, dmabuf.fourcc, dmabuf.modifier))
     {
-      if (gdk_dmabuf_downloader_supports (display->egl_downloader, self, error))
-        self->downloader = g_object_ref (display->egl_downloader);
-    }
-
-  if (!self->downloader && display->vk_downloader)
-    {
-      g_clear_error (error);
-      if (gdk_dmabuf_downloader_supports (display->vk_downloader, self, error))
-        self->downloader = g_object_ref (display->vk_downloader);
-    }
-
-  if (!self->downloader)
-    {
-      if (!gdk_dmabuf_formats_contains (gdk_dmabuf_get_mmap_formats (), dmabuf.fourcc, dmabuf.modifier))
-        {
-          g_object_unref (self);
-          return NULL;
-        }
-
-      g_clear_error (error);
+      g_set_error (error,
+                   GDK_DMABUF_ERROR, GDK_DMABUF_ERROR_UNSUPPORTED_FORMAT,
+                   "Unsupported dmabuf format: %.4s:%#" G_GINT64_MODIFIER "x",
+                   (char *) &dmabuf.fourcc, dmabuf.modifier);
+      g_object_unref (self);
+      return NULL;
     }
 
   GDK_DISPLAY_DEBUG (display, DMABUF,
-                     "Creating dmabuf texture, format %.4s:%#" G_GINT64_MODIFIER "x, %s%u planes, memory format %u, downloader %s",
+                     "Creating dmabuf texture, format %.4s:%#" G_GINT64_MODIFIER "x, %s%u planes, memory format %u",
                      (char *) &dmabuf.fourcc, dmabuf.modifier,
                      gdk_dmabuf_texture_builder_get_premultiplied (builder) ? " premultiplied, " : "",
                      dmabuf.n_planes,
-                     GDK_TEXTURE (self)->format,
-                     self->downloader ? G_OBJECT_TYPE_NAME (self->downloader) : "none");
+                     GDK_TEXTURE (self)->format);
 
   /* Set this only once we know that the texture will be created.
    * Otherwise dispose() will run the callback */