backend/wayland: listen to wl_buffer.release events

Previously, we just assumed submitting a new frame would make the
compositor release the current one. This isn't always the case, for
instance Sway retains old buffers when a transaction is pending. This
resulted in synchronization issues with clients writing in
front-buffers.

Fix this by un-referencing a wlr_buffer when the parent compositor sends
wl_buffer.release.

Tested by running a fullscreen mpv instance in Sway with the Wayland
backend.
This commit is contained in:
Simon Ser 2020-01-09 15:34:34 +01:00 committed by Drew DeVault
parent b5cb6de232
commit e6fd880686
2 changed files with 64 additions and 28 deletions

View File

@ -109,25 +109,39 @@ static bool output_attach_render(struct wlr_output *wlr_output,
buffer_age);
}
static bool output_attach_buffer(struct wlr_output *wlr_output,
struct wlr_buffer *buffer) {
struct wlr_wl_output *output =
get_wl_output_from_output(wlr_output);
struct wlr_wl_backend *wl = output->backend;
struct wlr_dmabuf_attributes attribs;
if (!wlr_buffer_get_dmabuf(buffer, &attribs)) {
return false;
static void destroy_wl_buffer(struct wlr_wl_buffer *buffer) {
if (buffer == NULL) {
return;
}
wl_buffer_destroy(buffer->wl_buffer);
wlr_buffer_unref(buffer->buffer);
free(buffer);
}
if (attribs.width != wlr_output->width ||
attribs.height != wlr_output->height) {
return false;
static void buffer_handle_release(void *data, struct wl_buffer *wl_buffer) {
struct wlr_wl_buffer *buffer = data;
destroy_wl_buffer(buffer);
}
static const struct wl_buffer_listener buffer_listener = {
.release = buffer_handle_release,
};
static struct wlr_wl_buffer *create_wl_buffer(struct wlr_wl_backend *wl,
struct wlr_buffer *wlr_buffer,
int required_width, int required_height) {
struct wlr_dmabuf_attributes attribs;
if (!wlr_buffer_get_dmabuf(wlr_buffer, &attribs)) {
return NULL;
}
if (attribs.width != required_width || attribs.height != required_height) {
return NULL;
}
if (!wlr_drm_format_set_has(&wl->linux_dmabuf_v1_formats,
attribs.format, attribs.modifier)) {
return false;
return NULL;
}
uint32_t modifier_hi = attribs.modifier >> 32;
@ -153,12 +167,33 @@ static bool output_attach_buffer(struct wlr_output *wlr_output,
params, attribs.width, attribs.height, attribs.format, flags);
// TODO: handle create() errors
wl_surface_attach(output->surface, wl_buffer, 0, 0);
if (output->pending_wl_buffer != NULL) {
wl_buffer_destroy(output->pending_wl_buffer);
struct wlr_wl_buffer *buffer = calloc(1, sizeof(struct wlr_wl_buffer));
if (buffer == NULL) {
wl_buffer_destroy(wl_buffer);
return NULL;
}
output->pending_wl_buffer = wl_buffer;
buffer->wl_buffer = wl_buffer;
buffer->buffer = wlr_buffer_ref(wlr_buffer);
wl_buffer_add_listener(wl_buffer, &buffer_listener, buffer);
return buffer;
}
static bool output_attach_buffer(struct wlr_output *wlr_output,
struct wlr_buffer *wlr_buffer) {
struct wlr_wl_output *output =
get_wl_output_from_output(wlr_output);
struct wlr_wl_backend *wl = output->backend;
struct wlr_wl_buffer *buffer = create_wl_buffer(wl, wlr_buffer,
wlr_output->width, wlr_output->height);
if (buffer == NULL) {
return false;
}
destroy_wl_buffer(output->pending_buffer);
output->pending_buffer = buffer;
return true;
}
@ -182,13 +217,6 @@ static bool output_commit(struct wlr_output *wlr_output) {
}
if (wlr_output->pending.committed & WLR_OUTPUT_STATE_BUFFER) {
wlr_buffer_unref(output->current_buffer);
output->current_buffer = NULL;
if (output->current_wl_buffer != NULL) {
wl_buffer_destroy(output->current_wl_buffer);
output->current_wl_buffer = NULL;
}
struct wp_presentation_feedback *wp_feedback = NULL;
if (output->backend->presentation != NULL) {
wp_feedback = wp_presentation_feedback(output->backend->presentation,
@ -216,6 +244,10 @@ static bool output_commit(struct wlr_output *wlr_output) {
}
break;
case WLR_OUTPUT_STATE_BUFFER_SCANOUT:
assert(output->pending_buffer != NULL);
wl_surface_attach(output->surface,
output->pending_buffer->wl_buffer, 0, 0);
if (damage == NULL) {
wl_surface_damage_buffer(output->surface,
0, 0, INT32_MAX, INT32_MAX);
@ -231,9 +263,7 @@ static bool output_commit(struct wlr_output *wlr_output) {
}
wl_surface_commit(output->surface);
output->current_buffer = wlr_buffer_ref(wlr_output->pending.buffer);
output->current_wl_buffer = output->pending_wl_buffer;
output->pending_wl_buffer = NULL;
output->pending_buffer = NULL;
break;
}
@ -359,6 +389,8 @@ static void output_destroy(struct wlr_output *wlr_output) {
presentation_feedback_destroy(feedback);
}
destroy_wl_buffer(output->pending_buffer);
wlr_egl_destroy_surface(&output->backend->egl, output->egl_surface);
wl_egl_window_destroy(output->egl_window);
if (output->zxdg_toplevel_decoration_v1) {

View File

@ -47,6 +47,11 @@ struct wlr_wl_backend {
struct wlr_drm_format_set linux_dmabuf_v1_formats;
};
struct wlr_wl_buffer {
struct wlr_buffer *buffer;
struct wl_buffer *wl_buffer;
};
struct wlr_wl_presentation_feedback {
struct wlr_wl_output *output;
struct wl_list link;
@ -67,8 +72,7 @@ struct wlr_wl_output {
struct zxdg_toplevel_decoration_v1 *zxdg_toplevel_decoration_v1;
struct wl_egl_window *egl_window;
EGLSurface egl_surface;
struct wl_buffer *pending_wl_buffer, *current_wl_buffer;
struct wlr_buffer *current_buffer;
struct wlr_wl_buffer *pending_buffer;
struct wl_list presentation_feedbacks;
uint32_t enter_serial;