From 5ecc1913326efcece5ec29dc0d90f40edd545548 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Poisot?= <felix@lhfblc.fr>
Date: Fri, 31 Jan 2025 18:36:07 +0000
Subject: [PATCH] scene: add buffer release point to 'sample' event

---
 include/wlr/types/wlr_scene.h |  4 ++++
 types/scene/wlr_scene.c       | 36 +++++++++++++++++++++++++++++++----
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index 0f4aa4c27..f864708a6 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -154,6 +154,8 @@ struct wlr_scene_outputs_update_event {
 struct wlr_scene_output_sample_event {
 	struct wlr_scene_output *output;
 	bool direct_scanout;
+	struct wlr_drm_syncobj_timeline *release_timeline;
+	uint64_t release_point;
 };
 
 struct wlr_scene_frame_done_event {
@@ -260,6 +262,8 @@ struct wlr_scene_output {
 
 		struct wlr_drm_syncobj_timeline *in_timeline;
 		uint64_t in_point;
+		struct wlr_drm_syncobj_timeline *out_timeline;
+		uint64_t out_point;
 	} WLR_PRIVATE;
 };
 
diff --git a/types/scene/wlr_scene.c b/types/scene/wlr_scene.c
index d2327eda2..f033386aa 100644
--- a/types/scene/wlr_scene.c
+++ b/types/scene/wlr_scene.c
@@ -1142,6 +1142,11 @@ static struct wlr_texture *scene_buffer_get_texture(
 	return texture;
 }
 
+static void scene_buffer_sample(struct wlr_scene_buffer *buffer,
+		struct wlr_scene_output_sample_event *event, struct wl_event_loop* loop) {
+	wl_signal_emit_mutable(&buffer->events.output_sample, event);
+}
+
 void scene_node_get_size(struct wlr_scene_node *node, int *width, int *height) {
 	*width = 0;
 	*height = 0;
@@ -1481,8 +1486,10 @@ static void scene_entry_render(struct render_list_entry *entry, const struct ren
 		struct wlr_scene_output_sample_event sample_event = {
 			.output = data->output,
 			.direct_scanout = false,
+			.release_timeline = data->output->in_timeline,
+			.release_point = data->output->in_point,
 		};
-		wl_signal_emit_mutable(&scene_buffer->events.output_sample, &sample_event);
+		scene_buffer_sample(scene_buffer, &sample_event, data->output->output->event_loop);
 
 		if (entry->highlight_transparent_region) {
 			wlr_render_pass_add_rect(data->render_pass, &(struct wlr_render_rect_options){
@@ -1694,7 +1701,10 @@ struct wlr_scene_output *wlr_scene_output_create(struct wlr_scene *scene,
 	if (drm_fd >= 0 && output->backend->features.timeline &&
 			output->renderer != NULL && output->renderer->features.timeline) {
 		scene_output->in_timeline = wlr_drm_syncobj_timeline_create(drm_fd);
-		if (scene_output->in_timeline == NULL) {
+		scene_output->out_timeline = wlr_drm_syncobj_timeline_create(drm_fd);
+		if (scene_output->in_timeline == NULL || scene_output->out_timeline == NULL) {
+			wlr_drm_syncobj_timeline_unref(scene_output->in_timeline);
+			wlr_drm_syncobj_timeline_unref(scene_output->out_timeline);
 			return NULL;
 		}
 	}
@@ -1749,7 +1759,14 @@ void wlr_scene_output_destroy(struct wlr_scene_output *scene_output) {
 	wl_list_remove(&scene_output->output_commit.link);
 	wl_list_remove(&scene_output->output_damage.link);
 	wl_list_remove(&scene_output->output_needs_frame.link);
-	wlr_drm_syncobj_timeline_unref(scene_output->in_timeline);
+	if (scene_output->in_timeline != NULL) {
+		wlr_drm_syncobj_timeline_signal(scene_output->in_timeline, UINT64_MAX);
+		wlr_drm_syncobj_timeline_unref(scene_output->in_timeline);
+	}
+	if (scene_output->out_timeline != NULL) {
+		wlr_drm_syncobj_timeline_signal(scene_output->out_timeline, UINT64_MAX);
+		wlr_drm_syncobj_timeline_unref(scene_output->out_timeline);
+	}
 	wl_array_release(&scene_output->render_list);
 	free(scene_output);
 }
@@ -2023,6 +2040,12 @@ static enum scene_direct_scanout_result scene_entry_try_direct_scanout(
 	if (buffer->wait_timeline != NULL) {
 		wlr_output_state_set_wait_timeline(&pending, buffer->wait_timeline, buffer->wait_point);
 	}
+
+	if (scene_output->out_timeline) {
+		scene_output->out_point++;
+		wlr_output_state_set_signal_timeline(&pending, scene_output->out_timeline, scene_output->out_point);
+	}
+
 	if (!wlr_output_test_state(scene_output->output, &pending)) {
 		wlr_output_state_finish(&pending);
 		return SCANOUT_CANDIDATE;
@@ -2034,8 +2057,10 @@ static enum scene_direct_scanout_result scene_entry_try_direct_scanout(
 	struct wlr_scene_output_sample_event sample_event = {
 		.output = scene_output,
 		.direct_scanout = true,
+		.release_timeline = data->output->out_timeline,
+		.release_point = data->output->out_point,
 	};
-	wl_signal_emit_mutable(&buffer->events.output_sample, &sample_event);
+	scene_buffer_sample(buffer, &sample_event, scene_output->output->event_loop);
 	return SCANOUT_SUCCESS;
 }
 
@@ -2414,6 +2439,9 @@ bool wlr_scene_output_build_state(struct wlr_scene_output *scene_output,
 	if (scene_output->in_timeline != NULL) {
 		wlr_output_state_set_wait_timeline(state, scene_output->in_timeline,
 			scene_output->in_point);
+		scene_output->out_point++;
+		wlr_output_state_set_signal_timeline(state, scene_output->out_timeline,
+			scene_output->out_point);
 	}
 
 	scene_output_state_attempt_gamma(scene_output, state);