From e0258f4506dc9d85a219c13b1e816022a145c65b Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Mon, 22 Mar 2021 19:27:29 +0100 Subject: [PATCH] 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 --- include/wlr/types/wlr_surface.h | 25 +++++++ types/wlr_surface.c | 116 ++++++++++++++++++++++++++++---- 2 files changed, 127 insertions(+), 14 deletions(-) diff --git a/include/wlr/types/wlr_surface.h b/include/wlr/types/wlr_surface.h index d247df0c..b44e50f5 100644 --- a/include/wlr/types/wlr_surface.h +++ b/include/wlr/types/wlr_surface.h @@ -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 diff --git a/types/wlr_surface.c b/types/wlr_surface.c index 80313192..6f99c924 100644 --- a/types/wlr_surface.c +++ b/types/wlr_surface.c @@ -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(