wayland/dma-buf: Add manager struct

It'll be used to store state related to DMA buffer Wayland support.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1959>

src/wayland/meta-wayland-dma-buf.c

@@ -66,6 +66,11 @@
 
 #define META_WAYLAND_DMA_BUF_MAX_FDS 4
 
+struct _MetaWaylandDmaBufManager
+{
+  MetaWaylandCompositor *compositor;
+};
+
 struct _MetaWaylandDmaBufBuffer
 {
   GObject parent;
@@ -713,17 +718,17 @@ send_modifiers (struct wl_resource *resource,
 
 static void
 dma_buf_bind (struct wl_client *client,
-              void             *data,
+              void             *user_data,
               uint32_t          version,
               uint32_t          id)
 {
-  MetaWaylandCompositor *compositor = data;
+  MetaWaylandDmaBufManager *dma_buf_manager = user_data;
   struct wl_resource *resource;
 
   resource = wl_resource_create (client, &zwp_linux_dmabuf_v1_interface,
                                  version, id);
   wl_resource_set_implementation (resource, &dma_buf_implementation,
-                                  compositor, NULL);
+                                  dma_buf_manager, NULL);
   send_modifiers (resource, DRM_FORMAT_ARGB8888);
   send_modifiers (resource, DRM_FORMAT_ABGR8888);
   send_modifiers (resource, DRM_FORMAT_XRGB8888);
@@ -740,38 +745,58 @@ dma_buf_bind (struct wl_client *client,
 }
 
 /**
- * meta_wayland_dma_buf_init:
+ * meta_wayland_dma_buf_manager_new:
  * @compositor: The #MetaWaylandCompositor
  *
  * Creates the global Wayland object that exposes the linux-dmabuf protocol.
  *
- * Returns: Whether the initialization was successful. If this is %FALSE,
+ * Returns: (transfer full): The MetaWaylandDmaBufManager instance.
- * clients won't be able to use the linux-dmabuf protocol to pass buffers.
  */
-gboolean
+MetaWaylandDmaBufManager *
-meta_wayland_dma_buf_init (MetaWaylandCompositor *compositor)
+meta_wayland_dma_buf_manager_new (MetaWaylandCompositor  *compositor,
+                                  GError                **error)
 {
   MetaBackend *backend = meta_get_backend ();
   MetaEgl *egl = meta_backend_get_egl (backend);
   ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
   CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
   EGLDisplay egl_display = cogl_egl_context_get_egl_display (cogl_context);
+  g_autoptr (GError) local_error = NULL;
+  g_autofree MetaWaylandDmaBufManager *dma_buf_manager = NULL;
 
   g_assert (backend && egl && clutter_backend && cogl_context && egl_display);
 
   if (!meta_egl_has_extensions (egl, egl_display, NULL,
                                 "EGL_EXT_image_dma_buf_import_modifiers",
                                 NULL))
-    return FALSE;
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                   "Missing 'EGL_EXT_image_dma_buf_import_modifiers'");
+      return NULL;
+    }
+
+  dma_buf_manager = g_new0 (MetaWaylandDmaBufManager, 1);
 
   if (!wl_global_create (compositor->wayland_display,
                          &zwp_linux_dmabuf_v1_interface,
                          META_ZWP_LINUX_DMABUF_V1_VERSION,
-                         compositor,
+                         dma_buf_manager,
                          dma_buf_bind))
-    return FALSE;
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Failed to create zwp_linux_dmabuf_v1 global");
+      return NULL;
+    }
 
-  return TRUE;
+  dma_buf_manager->compositor = compositor;
+
+  return g_steal_pointer (&dma_buf_manager);
+}
+
+void
+meta_wayland_dma_buf_manager_free (MetaWaylandDmaBufManager *dma_buf_manager)
+{
+  g_free (dma_buf_manager);
 }
 
 static void

src/wayland/meta-wayland-dma-buf.h

@@ -39,7 +39,10 @@ G_DECLARE_FINAL_TYPE (MetaWaylandDmaBufBuffer, meta_wayland_dma_buf_buffer,
 
 typedef struct _MetaWaylandDmaBufBuffer MetaWaylandDmaBufBuffer;
 
-gboolean meta_wayland_dma_buf_init (MetaWaylandCompositor *compositor);
+MetaWaylandDmaBufManager * meta_wayland_dma_buf_manager_new (MetaWaylandCompositor  *compositor,
+                                                             GError                **error);
+
+void meta_wayland_dma_buf_manager_free (MetaWaylandDmaBufManager *dma_buf_manager);
 
 gboolean
 meta_wayland_dma_buf_buffer_attach (MetaWaylandBuffer  *buffer,

src/wayland/meta-wayland-private.h

@@ -100,6 +100,7 @@ struct _MetaWaylandCompositor
   GHashTable *scheduled_surface_associations;
 
   MetaWaylandPresentationTime presentation_time;
+  MetaWaylandDmaBufManager *dma_buf_manager;
 };
 
 #define META_TYPE_WAYLAND_COMPOSITOR (meta_wayland_compositor_get_type ())

src/wayland/meta-wayland-types.h

@@ -63,4 +63,6 @@ typedef struct _MetaWaylandPointerClient MetaWaylandPointerClient;
 
 typedef struct _MetaWaylandActivation MetaWaylandActivation;
 
+typedef struct _MetaWaylandDmaBufManager MetaWaylandDmaBufManager;
+
 #endif

src/wayland/meta-wayland.c

@@ -437,6 +437,9 @@ meta_wayland_compositor_finalize (GObject *object)
 {
   MetaWaylandCompositor *compositor = META_WAYLAND_COMPOSITOR (object);
 
+  g_clear_pointer (&compositor->dma_buf_manager,
+                   meta_wayland_dma_buf_manager_free);
+
   g_clear_pointer (&compositor->seat, meta_wayland_seat_free);
 
   g_clear_pointer (&compositor->display_name, g_free);
@@ -526,6 +529,29 @@ meta_wayland_init_egl (MetaWaylandCompositor *compositor)
     g_warning ("Failed to bind Wayland display: %s", error->message);
 }
 
+static void
+init_dma_buf_support (MetaWaylandCompositor *compositor)
+{
+  g_autoptr (GError) error = NULL;
+
+  compositor->dma_buf_manager = meta_wayland_dma_buf_manager_new (compositor,
+                                                                  &error);
+  if (!compositor->dma_buf_manager)
+    {
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
+        {
+          meta_topic (META_DEBUG_WAYLAND,
+                      "Wayland DMA buffer protocol support not enabled: %s",
+                      error->message);
+        }
+      else
+        {
+          g_warning ("Wayland DMA buffer protocol support not enabled: %s",
+                     error->message);
+        }
+    }
+}
+
 MetaWaylandCompositor *
 meta_wayland_compositor_new (MetaContext *context)
 {
@@ -577,7 +603,7 @@ meta_wayland_compositor_new (MetaContext *context)
   meta_wayland_relative_pointer_init (compositor);
   meta_wayland_pointer_constraints_init (compositor);
   meta_wayland_xdg_foreign_init (compositor);
-  meta_wayland_dma_buf_init (compositor);
+  init_dma_buf_support (compositor);
   meta_wayland_keyboard_shortcuts_inhibit_init (compositor);
   meta_wayland_surface_inhibit_shortcuts_dialog_init ();
   meta_wayland_text_input_init (compositor);