surface: introduce cached states

Cached states allow a surface commit to be delayed. They are useful for:

- Subsurfaces
- The upcoming transactions protocol [1]
- Explicit synchronization

[1]: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/26
This commit is contained in:
Simon Ser 2021-03-22 19:27:29 +01:00
parent 7ac76aba8a
commit e0258f4506
2 changed files with 127 additions and 14 deletions

View file

@ -62,6 +62,10 @@ struct wlr_surface_state {
} viewport;
struct wl_listener buffer_destroy;
// Number of locks that prevent this surface state from being committed.
size_t cached_state_locks;
struct wl_list cached_state_link; // wlr_surface.cached
};
struct wlr_surface_role {
@ -124,6 +128,8 @@ struct wlr_surface {
*/
struct wlr_surface_state current, pending, previous;
struct wl_list cached; // wlr_surface_state.cached_link
const struct wlr_surface_role *role; // the lifetime-bound role or NULL
void *role_data; // role-specific data
@ -293,4 +299,23 @@ void wlr_surface_get_effective_damage(struct wlr_surface *surface,
void wlr_surface_get_buffer_source_box(struct wlr_surface *surface,
struct wlr_fbox *box);
/**
* Acquire a lock for the pending surface state.
*
* The state won't be committed before the caller releases the lock. Instead,
* the state becomes cached. The caller needs to use wlr_surface_unlock_cached
* to release the lock.
*
* Returns a surface commit sequence number for the cached state.
*/
uint32_t wlr_surface_lock_pending(struct wlr_surface *surface);
/**
* Release a lock for a cached state.
*
* Callers should not assume that the cached state will immediately be
* committed. Another caller may still have an active lock.
*/
void wlr_surface_unlock_cached(struct wlr_surface *surface, uint32_t seq);
#endif

View file

@ -296,6 +296,7 @@ static void surface_state_copy(struct wlr_surface_state *state,
state->committed |= next->committed;
state->seq = next->seq;
state->cached_state_locks = next->cached_state_locks;
}
/**
@ -323,6 +324,7 @@ static void surface_state_move(struct wlr_surface_state *state,
}
next->committed = 0;
next->cached_state_locks = 0;
}
static void surface_damage_subsurfaces(struct wlr_subsurface *subsurface) {
@ -401,25 +403,33 @@ static void surface_update_input_region(struct wlr_surface *surface) {
0, 0, surface->current.width, surface->current.height);
}
static void surface_commit_pending(struct wlr_surface *surface) {
if (!surface_state_finalize(surface, &surface->pending)) {
static void surface_state_init(struct wlr_surface_state *state);
static void surface_cache_pending(struct wlr_surface *surface) {
struct wlr_surface_state *cached = calloc(1, sizeof(*cached));
if (!cached) {
wl_resource_post_no_memory(surface->resource);
return;
}
if (surface->role && surface->role->precommit) {
surface->role->precommit(surface);
}
surface_state_init(cached);
surface_state_move(cached, &surface->pending);
bool invalid_buffer = surface->pending.committed & WLR_SURFACE_STATE_BUFFER;
wl_list_insert(surface->cached.prev, &cached->cached_state_link);
}
surface->sx += surface->pending.dx;
surface->sy += surface->pending.dy;
surface_update_damage(&surface->buffer_damage,
&surface->current, &surface->pending);
static void surface_commit_state(struct wlr_surface *surface,
struct wlr_surface_state *next) {
assert(next->cached_state_locks == 0);
bool invalid_buffer = next->committed & WLR_SURFACE_STATE_BUFFER;
surface->sx += next->dx;
surface->sy += next->dy;
surface_update_damage(&surface->buffer_damage, &surface->current, next);
surface_state_copy(&surface->previous, &surface->current);
surface_state_move(&surface->current, &surface->pending);
surface->pending.seq = surface->current.seq + 1;
surface_state_move(&surface->current, next);
if (invalid_buffer) {
surface_apply_damage(surface);
@ -447,6 +457,24 @@ static void surface_commit_pending(struct wlr_surface *surface) {
wlr_signal_emit_safe(&surface->events.commit, surface);
}
static void surface_commit_pending(struct wlr_surface *surface) {
if (!surface_state_finalize(surface, &surface->pending)) {
return;
}
if (surface->role && surface->role->precommit) {
surface->role->precommit(surface);
}
uint32_t next_seq = surface->pending.seq + 1;
if (surface->pending.cached_state_locks > 0 || !wl_list_empty(&surface->cached)) {
surface_cache_pending(surface);
} else {
surface_commit_state(surface, &surface->pending);
}
surface->pending.seq = next_seq;
}
static bool subsurface_is_synchronized(struct wlr_subsurface *subsurface) {
while (subsurface != NULL) {
if (subsurface->synchronized) {
@ -607,6 +635,12 @@ static void surface_state_finish(struct wlr_surface_state *state) {
pixman_region32_fini(&state->input);
}
static void surface_state_destroy_cached(struct wlr_surface_state *state) {
surface_state_finish(state);
wl_list_remove(&state->cached_state_link);
free(state);
}
static void subsurface_unmap(struct wlr_subsurface *subsurface);
static void subsurface_destroy(struct wlr_subsurface *subsurface) {
@ -637,10 +671,11 @@ static void subsurface_destroy(struct wlr_subsurface *subsurface) {
static void surface_output_destroy(struct wlr_surface_output *surface_output);
static void surface_handle_resource_destroy(struct wl_resource *resource) {
struct wlr_surface_output *surface_output, *tmp;
struct wlr_surface *surface = wlr_surface_from_resource(resource);
wl_list_for_each_safe(surface_output, tmp, &surface->current_outputs, link) {
struct wlr_surface_output *surface_output, *surface_output_tmp;
wl_list_for_each_safe(surface_output, surface_output_tmp,
&surface->current_outputs, link) {
surface_output_destroy(surface_output);
}
@ -648,6 +683,11 @@ static void surface_handle_resource_destroy(struct wl_resource *resource) {
wl_list_remove(wl_resource_get_link(surface->resource));
struct wlr_surface_state *cached, *cached_tmp;
wl_list_for_each_safe(cached, cached_tmp, &surface->cached, cached_state_link) {
surface_state_destroy_cached(cached);
}
wl_list_remove(&surface->renderer_destroy.link);
surface_state_finish(&surface->pending);
surface_state_finish(&surface->current);
@ -703,6 +743,7 @@ struct wlr_surface *wlr_surface_create(struct wl_client *client,
wl_list_init(&surface->subsurfaces);
wl_list_init(&surface->subsurface_pending_list);
wl_list_init(&surface->current_outputs);
wl_list_init(&surface->cached);
pixman_region32_init(&surface->buffer_damage);
pixman_region32_init(&surface->opaque_region);
pixman_region32_init(&surface->input_region);
@ -758,6 +799,53 @@ bool wlr_surface_set_role(struct wlr_surface *surface,
return true;
}
uint32_t wlr_surface_lock_pending(struct wlr_surface *surface) {
surface->pending.cached_state_locks++;
return surface->pending.seq;
}
void wlr_surface_unlock_cached(struct wlr_surface *surface, uint32_t seq) {
if (surface->pending.seq == seq) {
assert(surface->pending.cached_state_locks > 0);
surface->pending.cached_state_locks--;
return;
}
bool found = false;
struct wlr_surface_state *cached;
wl_list_for_each(cached, &surface->cached, cached_state_link) {
if (cached->seq == seq) {
found = true;
break;
}
}
assert(found);
assert(cached->cached_state_locks > 0);
cached->cached_state_locks--;
if (cached->cached_state_locks != 0) {
return;
}
if (cached->cached_state_link.prev != &surface->cached) {
// This isn't the first cached state. This means we're blocked on a
// previous cached state.
return;
}
// TODO: consider merging all committed states together
struct wlr_surface_state *next, *tmp;
wl_list_for_each_safe(next, tmp, &surface->cached, cached_state_link) {
if (next->cached_state_locks > 0) {
break;
}
surface_commit_state(surface, next);
surface_state_destroy_cached(next);
}
}
static const struct wl_subsurface_interface subsurface_implementation;
static struct wlr_subsurface *subsurface_from_resource(