+static void
+droid_display_shared_buffer(__DRIdrawable *driDrawable, int fence_fd,
+ void *loaderPrivate)
+{
+ struct dri2_egl_surface *dri2_surf = loaderPrivate;
+ struct ANativeWindowBuffer *old_buffer UNUSED = dri2_surf->buffer;
+
+ if (!_eglSurfaceInSharedBufferMode(&dri2_surf->base)) {
+ _eglLog(_EGL_WARNING, "%s: internal error: buffer is not shared",
+ __func__);
+ return;
+ }
+
+ if (fence_fd >= 0) {
+ /* The driver's fence is more recent than the surface's out fence, if it
+ * exists at all. So use the driver's fence.
+ */
+ if (dri2_surf->out_fence_fd >= 0) {
+ close(dri2_surf->out_fence_fd);
+ dri2_surf->out_fence_fd = -1;
+ }
+ } else if (dri2_surf->out_fence_fd >= 0) {
+ fence_fd = dri2_surf->out_fence_fd;
+ dri2_surf->out_fence_fd = -1;
+ }
+
+ if (dri2_surf->window->queueBuffer(dri2_surf->window, dri2_surf->buffer,
+ fence_fd)) {
+ _eglLog(_EGL_WARNING, "%s: ANativeWindow::queueBuffer failed", __func__);
+ close(fence_fd);
+ return;
+ }
+
+ fence_fd = -1;
+
+ if (dri2_surf->window->dequeueBuffer(dri2_surf->window, &dri2_surf->buffer,
+ &fence_fd)) {
+ /* Tear down the surface because it no longer has a back buffer. */
+ struct dri2_egl_display *dri2_dpy =
+ dri2_egl_display(dri2_surf->base.Resource.Display);
+
+ _eglLog(_EGL_WARNING, "%s: ANativeWindow::dequeueBuffer failed", __func__);
+
+ dri2_surf->base.Lost = true;
+ dri2_surf->buffer = NULL;
+ dri2_surf->back = NULL;
+
+ if (dri2_surf->dri_image_back) {
+ dri2_dpy->image->destroyImage(dri2_surf->dri_image_back);
+ dri2_surf->dri_image_back = NULL;
+ }
+
+ dri2_dpy->flush->invalidate(dri2_surf->dri_drawable);
+ return;
+ }
+
+ if (fence_fd < 0)
+ return;
+
+ /* Access to the buffer is controlled by a sync fence. Block on it.
+ *
+ * Ideally, we would submit the fence to the driver, and the driver would
+ * postpone command execution until it signalled. But DRI lacks API for
+ * that (as of 2018-04-11).
+ *
+ * SYNC_IOC_WAIT waits forever if timeout < 0
+ */
+ sync_wait(fence_fd, -1);
+ close(fence_fd);
+}
+
+static const __DRImutableRenderBufferLoaderExtension droid_mutable_render_buffer_extension = {
+ .base = { __DRI_MUTABLE_RENDER_BUFFER_LOADER, 1 },
+ .displaySharedBuffer = droid_display_shared_buffer,