linux-drm-syncobj-v1: new protocol implementation

References: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/90

include/wlr/types/wlr_linux_drm_syncobj_v1.h

@@ -0,0 +1,46 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_LINUX_DRM_SYNCOBJ_V1_H
+#define WLR_TYPES_WLR_LINUX_DRM_SYNCOBJ_V1_H
+
+#include <wayland-server-core.h>
+#include <wlr/util/addon.h>
+
+struct wlr_linux_drm_syncobj_surface_v1_state {
+	struct wlr_drm_syncobj_timeline *acquire_timeline;
+	uint64_t acquire_point;
+
+	struct wlr_drm_syncobj_timeline *release_timeline;
+	uint64_t release_point;
+};
+
+struct wlr_linux_drm_syncobj_manager_v1 {
+	struct wl_global *global;
+
+	// private state
+
+	int drm_fd;
+
+	struct wl_listener display_destroy;
+};
+
+/**
+ * Advertise explicit synchronization support to clients.
+ *
+ * The compositor must be prepared to handle fences coming from clients and to
+ * send release fences correctly. In particular, both the renderer and the
+ * backend need to support explicit synchronization.
+ */
+struct wlr_linux_drm_syncobj_manager_v1 *wlr_linux_drm_syncobj_manager_v1_create(
+	struct wl_display *display, uint32_t version, int drm_fd);
+
+struct wlr_linux_drm_syncobj_surface_v1_state *wlr_linux_drm_syncobj_v1_get_surface_state(
+	struct wlr_surface *surface);
+
+#endif

protocol/meson.build

@@ -27,6 +27,7 @@ protocols = {
 	'ext-idle-notify-v1': wl_protocol_dir / 'staging/ext-idle-notify/ext-idle-notify-v1.xml',
 	'ext-session-lock-v1': wl_protocol_dir / 'staging/ext-session-lock/ext-session-lock-v1.xml',
 	'fractional-scale-v1': wl_protocol_dir / 'staging/fractional-scale/fractional-scale-v1.xml',
+	'linux-drm-syncobj-v1': wl_protocol_dir / 'staging/linux-drm-syncobj/linux-drm-syncobj-v1.xml',
 	'security-context-v1': wl_protocol_dir / 'staging/security-context/security-context-v1.xml',
 	'single-pixel-buffer-v1': wl_protocol_dir / 'staging/single-pixel-buffer/single-pixel-buffer-v1.xml',
 	'xdg-activation-v1': wl_protocol_dir / 'staging/xdg-activation/xdg-activation-v1.xml',

types/meson.build

@@ -55,6 +55,7 @@ wlr_files += files(
 	'wlr_keyboard_shortcuts_inhibit_v1.c',
 	'wlr_layer_shell_v1.c',
 	'wlr_linux_dmabuf_v1.c',
+	'wlr_linux_drm_syncobj_v1.c',
 	'wlr_matrix.c',
 	'wlr_output_layer.c',
 	'wlr_output_layout.c',

types/wlr_linux_drm_syncobj_v1.c

@@ -0,0 +1,469 @@
+#include <assert.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <wlr/render/drm_syncobj.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_linux_drm_syncobj_v1.h>
+#include <wlr/util/log.h>
+#include <xf86drm.h>
+#include "config.h"
+#include "linux-drm-syncobj-v1-protocol.h"
+
+#define LINUX_DRM_SYNCOBJ_V1_VERSION 1
+
+struct wlr_linux_drm_syncobj_surface_v1 {
+	struct wl_resource *resource;
+	struct wlr_surface *surface;
+	struct wlr_linux_drm_syncobj_surface_v1_state pending, current;
+
+	struct wlr_addon addon;
+	struct wlr_surface_synced synced;
+
+	struct wl_listener client_commit;
+};
+
+struct wlr_linux_drm_syncobj_surface_v1_commit {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface;
+	struct wlr_drm_syncobj_timeline_waiter waiter;
+	uint32_t cached_seq;
+
+	struct wl_listener waiter_ready;
+	struct wl_listener surface_destroy;
+};
+
+static const struct wp_linux_drm_syncobj_manager_v1_interface manager_impl;
+static const struct wp_linux_drm_syncobj_timeline_v1_interface timeline_impl;
+static const struct wp_linux_drm_syncobj_surface_v1_interface surface_impl;
+
+static struct wlr_linux_drm_syncobj_manager_v1 *manager_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource,
+		&wp_linux_drm_syncobj_manager_v1_interface, &manager_impl));
+	return wl_resource_get_user_data(resource);
+}
+
+static struct wlr_drm_syncobj_timeline *timeline_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource,
+		&wp_linux_drm_syncobj_timeline_v1_interface, &timeline_impl));
+	return wl_resource_get_user_data(resource);
+}
+
+// Returns NULL if the syncobj surface is inert
+static struct wlr_linux_drm_syncobj_surface_v1 *surface_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource,
+		&wp_linux_drm_syncobj_surface_v1_interface, &surface_impl));
+	return wl_resource_get_user_data(resource);
+}
+
+static void timeline_handle_resource_destroy(struct wl_resource *resource) {
+	struct wlr_drm_syncobj_timeline *timeline = timeline_from_resource(resource);
+	wlr_drm_syncobj_timeline_unref(timeline);
+}
+
+static void timeline_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static const struct wp_linux_drm_syncobj_timeline_v1_interface timeline_impl = {
+	.destroy = timeline_handle_destroy,
+};
+
+static void surface_destroy(struct wlr_linux_drm_syncobj_surface_v1 *surface) {
+	if (surface == NULL) {
+		return;
+	}
+	wl_list_remove(&surface->client_commit.link);
+	wlr_addon_finish(&surface->addon);
+	wlr_surface_synced_finish(&surface->synced);
+	wl_resource_set_user_data(surface->resource, NULL);
+	free(surface);
+}
+
+static void surface_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static void surface_handle_set_acquire_point(struct wl_client *client,
+		struct wl_resource *resource, struct wl_resource *timeline_resource,
+		uint32_t point_hi, uint32_t point_lo) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		surface_from_resource(resource);
+	if (surface == NULL) {
+		wl_resource_post_error(resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_SURFACE,
+			"The surface has been destroyed");
+		return;
+	}
+
+	struct wlr_drm_syncobj_timeline *timeline =
+		timeline_from_resource(timeline_resource);
+	uint64_t point = (uint64_t)point_hi << 32 | point_lo;
+
+	wlr_drm_syncobj_timeline_unref(surface->pending.acquire_timeline);
+	surface->pending.acquire_timeline = wlr_drm_syncobj_timeline_ref(timeline);
+	surface->pending.acquire_point = point;
+}
+
+static void surface_handle_set_release_point(struct wl_client *client,
+		struct wl_resource *resource, struct wl_resource *timeline_resource,
+		uint32_t point_hi, uint32_t point_lo) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		surface_from_resource(resource);
+	if (surface == NULL) {
+		wl_resource_post_error(resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_SURFACE,
+			"The surface has been destroyed");
+		return;
+	}
+
+	struct wlr_drm_syncobj_timeline *timeline =
+		timeline_from_resource(timeline_resource);
+	uint64_t point = (uint64_t)point_hi << 32 | point_lo;
+
+	wlr_drm_syncobj_timeline_unref(surface->pending.release_timeline);
+	surface->pending.release_timeline = wlr_drm_syncobj_timeline_ref(timeline);
+	surface->pending.release_point = point;
+}
+
+static const struct wp_linux_drm_syncobj_surface_v1_interface surface_impl = {
+	.destroy = surface_handle_destroy,
+	.set_acquire_point = surface_handle_set_acquire_point,
+	.set_release_point = surface_handle_set_release_point,
+};
+
+static void surface_handle_resource_destroy(struct wl_resource *resource) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		surface_from_resource(resource);
+	surface_destroy(surface);
+}
+
+static void surface_addon_handle_surface_destroy(struct wlr_addon *addon) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		wl_container_of(addon, surface, addon);
+	surface_destroy(surface);
+}
+
+static const struct wlr_addon_interface surface_addon_impl = {
+	.name = "wp_linux_drm_syncobj_surface_v1",
+	.destroy = surface_addon_handle_surface_destroy,
+};
+
+static void surface_synced_finish_state(void *_state) {
+	struct wlr_linux_drm_syncobj_surface_v1_state *state = _state;
+	wlr_drm_syncobj_timeline_unref(state->acquire_timeline);
+	wlr_drm_syncobj_timeline_unref(state->release_timeline);
+}
+
+static void surface_synced_move_state(void *_dst, void *_src) {
+	struct wlr_linux_drm_syncobj_surface_v1_state *dst = _dst, *src = _src;
+	// TODO: immediately signal dst.release_timeline if necessary
+	surface_synced_finish_state(dst);
+	*dst = *src;
+	*src = (struct wlr_linux_drm_syncobj_surface_v1_state){0};
+}
+
+static const struct wlr_surface_synced_impl surface_synced_impl = {
+	.state_size = sizeof(struct wlr_linux_drm_syncobj_surface_v1_state),
+	.finish_state = surface_synced_finish_state,
+	.move_state = surface_synced_move_state,
+};
+
+static void manager_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static struct wlr_linux_drm_syncobj_surface_v1 *surface_from_wlr_surface(
+		struct wlr_surface *wlr_surface) {
+	struct wlr_addon *addon =
+		wlr_addon_find(&wlr_surface->addons, NULL, &surface_addon_impl);
+	if (addon == NULL) {
+		return NULL;
+	}
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		wl_container_of(addon, surface, addon);
+	return surface;
+}
+
+static void surface_commit_destroy(struct wlr_linux_drm_syncobj_surface_v1_commit *commit) {
+	wlr_surface_unlock_cached(commit->surface->surface, commit->cached_seq);
+	wl_list_remove(&commit->surface_destroy.link);
+	wl_list_remove(&commit->waiter_ready.link);
+	wlr_drm_syncobj_timeline_waiter_finish(&commit->waiter);
+	free(commit);
+}
+
+static void surface_commit_handle_waiter_ready(struct wl_listener *listener, void *data) {
+	struct wlr_linux_drm_syncobj_surface_v1_commit *commit =
+		wl_container_of(listener, commit, waiter_ready);
+	surface_commit_destroy(commit);
+}
+
+static void surface_commit_handle_surface_destroy(struct wl_listener *listener,
+		void *data) {
+	struct wlr_linux_drm_syncobj_surface_v1_commit *commit =
+		wl_container_of(listener, commit, surface_destroy);
+	surface_commit_destroy(commit);
+}
+
+// Block the surface commit until the fence materializes
+static bool lock_surface_commit(struct wlr_linux_drm_syncobj_surface_v1 *surface,
+		struct wlr_drm_syncobj_timeline *timeline, uint64_t point) {
+	uint32_t flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE;
+
+	bool already_materialized = false;
+	if (!wlr_drm_syncobj_timeline_check(timeline, point, flags, &already_materialized)) {
+		return false;
+	} else if (already_materialized) {
+		return true;
+	}
+
+	struct wlr_linux_drm_syncobj_surface_v1_commit *commit = calloc(1, sizeof(*commit));
+	if (commit == NULL) {
+		return false;
+	}
+
+	struct wl_client *client = wl_resource_get_client(surface->resource);
+	struct wl_display *display = wl_client_get_display(client);
+	struct wl_event_loop *loop = wl_display_get_event_loop(display);
+	if (!wlr_drm_syncobj_timeline_waiter_init(&commit->waiter, timeline, point,
+			flags, loop)) {
+		free(commit);
+		return false;
+	}
+
+	commit->surface = surface;
+	commit->cached_seq = wlr_surface_lock_pending(surface->surface);
+
+	commit->waiter_ready.notify = surface_commit_handle_waiter_ready;
+	wl_signal_add(&commit->waiter.events.ready, &commit->waiter_ready);
+
+	commit->surface_destroy.notify = surface_commit_handle_surface_destroy;
+	wl_signal_add(&surface->surface->events.destroy, &commit->surface_destroy);
+
+	return true;
+}
+
+static void surface_handle_client_commit(struct wl_listener *listener,
+		void *data) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		wl_container_of(listener, surface, client_commit);
+
+	if (surface->pending.acquire_timeline != NULL &&
+			surface->surface->pending.buffer == NULL) {
+		wlr_surface_reject_pending(surface->surface, surface->resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_BUFFER,
+			"Acquire point set but no buffer attached");
+		return;
+	}
+	if (surface->pending.release_timeline != NULL &&
+			surface->surface->pending.buffer == NULL) {
+		wlr_surface_reject_pending(surface->surface, surface->resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_BUFFER,
+			"Release point set but no buffer attached");
+		return;
+	}
+
+	if (surface->pending.acquire_timeline == NULL &&
+			surface->surface->pending.buffer != NULL) {
+		wlr_surface_reject_pending(surface->surface, surface->resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_ACQUIRE_POINT,
+			"Buffer attached but no acquire point set");
+		return;
+	}
+	if (surface->pending.release_timeline == NULL &&
+			surface->surface->pending.buffer != NULL) {
+		wlr_surface_reject_pending(surface->surface, surface->resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_NO_RELEASE_POINT,
+			"Buffer attached but no release point set");
+		return;
+	}
+
+	if (surface->pending.acquire_timeline != NULL &&
+			surface->pending.release_timeline != NULL &&
+			surface->pending.acquire_timeline == surface->pending.release_timeline &&
+			surface->pending.acquire_point >= surface->pending.release_point) {
+		wlr_surface_reject_pending(surface->surface, surface->resource,
+			WP_LINUX_DRM_SYNCOBJ_SURFACE_V1_ERROR_CONFLICTING_POINTS,
+			"Acquire and release points conflict");
+		return;
+	}
+
+	if (surface->pending.acquire_timeline != NULL && !lock_surface_commit(
+			surface, surface->pending.acquire_timeline, surface->pending.acquire_point)) {
+		wl_resource_post_no_memory(surface->resource);
+		return;
+	}
+}
+
+static void manager_handle_get_surface(struct wl_client *client,
+		struct wl_resource *resource, uint32_t id,
+		struct wl_resource *surface_resource) {
+	struct wlr_surface *wlr_surface = wlr_surface_from_resource(surface_resource);
+
+	if (surface_from_wlr_surface(wlr_surface) != NULL) {
+		wl_resource_post_error(resource,
+			WP_LINUX_DRM_SYNCOBJ_MANAGER_V1_ERROR_SURFACE_EXISTS,
+			"wp_linux_drm_syncobj_surface_v1 already created for this surface");
+		return;
+	}
+
+	struct wlr_linux_drm_syncobj_surface_v1 *surface = calloc(1, sizeof(*surface));
+	if (surface == NULL) {
+		wl_resource_post_no_memory(resource);
+		return;
+	}
+
+	if (!wlr_surface_synced_init(&surface->synced, wlr_surface,
+			&surface_synced_impl, &surface->pending, &surface->current)) {
+		goto error_surface;
+	}
+
+	uint32_t version = wl_resource_get_version(resource);
+	surface->resource = wl_resource_create(client,
+		&wp_linux_drm_syncobj_surface_v1_interface, version, id);
+	if (surface->resource == NULL) {
+		goto error_surface_synced;
+	}
+	wl_resource_set_implementation(surface->resource,
+		&surface_impl, surface, surface_handle_resource_destroy);
+
+	surface->surface = wlr_surface;
+
+	surface->client_commit.notify = surface_handle_client_commit;
+	wl_signal_add(&wlr_surface->events.client_commit, &surface->client_commit);
+
+	wlr_addon_init(&surface->addon, &wlr_surface->addons, NULL, &surface_addon_impl);
+
+	return;
+
+error_surface_synced:
+	wlr_surface_synced_finish(&surface->synced);
+error_surface:
+	free(surface);
+	wl_resource_post_no_memory(resource);
+}
+
+static void manager_handle_import_timeline(struct wl_client *client,
+		struct wl_resource *resource, uint32_t id, int drm_syncobj_fd) {
+	struct wlr_linux_drm_syncobj_manager_v1 *manager =
+		manager_from_resource(resource);
+
+	struct wlr_drm_syncobj_timeline *timeline =
+		wlr_drm_syncobj_timeline_import(manager->drm_fd, drm_syncobj_fd);
+	close(drm_syncobj_fd);
+	if (timeline == NULL) {
+		wl_resource_post_error(resource,
+			WP_LINUX_DRM_SYNCOBJ_MANAGER_V1_ERROR_INVALID_TIMELINE,
+			"Failed to import drm_syncobj timeline");
+		return;
+	}
+
+	uint32_t version = wl_resource_get_version(resource);
+	struct wl_resource *timeline_resource = wl_resource_create(client,
+		&wp_linux_drm_syncobj_timeline_v1_interface, version, id);
+	if (timeline_resource == NULL) {
+		wl_resource_post_no_memory(resource);
+		return;
+	}
+	wl_resource_set_implementation(timeline_resource,
+		&timeline_impl, timeline, timeline_handle_resource_destroy);
+}
+
+static const struct wp_linux_drm_syncobj_manager_v1_interface manager_impl = {
+	.destroy = manager_handle_destroy,
+	.get_surface = manager_handle_get_surface,
+	.import_timeline = manager_handle_import_timeline,
+};
+
+static void manager_bind(struct wl_client *client, void *data,
+		uint32_t version, uint32_t id) {
+	struct wlr_linux_drm_syncobj_manager_v1 *manager = data;
+
+	struct wl_resource *resource = wl_resource_create(client,
+		&wp_linux_drm_syncobj_manager_v1_interface, version, id);
+	if (resource == NULL) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+	wl_resource_set_implementation(resource, &manager_impl, manager, NULL);
+}
+
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_linux_drm_syncobj_manager_v1 *manager =
+		wl_container_of(listener, manager, display_destroy);
+	wl_list_remove(&manager->display_destroy.link);
+	wl_global_destroy(manager->global);
+	close(manager->drm_fd);
+	free(manager);
+}
+
+static bool check_syncobj_eventfd(int drm_fd) {
+	if (!HAVE_EVENTFD) {
+		return false;
+	}
+
+	uint64_t value = 0;
+	if (drmGetCap(drm_fd, DRM_CAP_SYNCOBJ_TIMELINE, &value) != 0 || value == 0) {
+		return false;
+	}
+
+	// Try waiting with invalid syncobj should fail with ENOENT
+	struct drm_syncobj_eventfd syncobj_eventfd = {
+		.handle = 0,
+		.fd = -1,
+	};
+	return drmIoctl(drm_fd, DRM_IOCTL_SYNCOBJ_EVENTFD, &syncobj_eventfd) != 0 && errno == ENOENT;
+}
+
+struct wlr_linux_drm_syncobj_manager_v1 *wlr_linux_drm_syncobj_manager_v1_create(
+		struct wl_display *display, uint32_t version, int drm_fd) {
+	if (!check_syncobj_eventfd(drm_fd)) {
+		wlr_log(WLR_INFO, "DRM syncobj eventfd unavailable, disabling linux-drm-syncobj-v1");
+		return NULL;
+	}
+
+	struct wlr_linux_drm_syncobj_manager_v1 *manager = calloc(1, sizeof(*manager));
+	if (manager == NULL) {
+		return NULL;
+	}
+
+	manager->drm_fd = fcntl(drm_fd, F_DUPFD_CLOEXEC, 0);
+	if (manager->drm_fd < 0) {
+		goto error_manager;
+	}
+
+	manager->global = wl_global_create(display,
+		&wp_linux_drm_syncobj_manager_v1_interface,
+		LINUX_DRM_SYNCOBJ_V1_VERSION, manager, manager_bind);
+	if (manager->global == NULL) {
+		goto error_drm_fd;
+	}
+
+	manager->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &manager->display_destroy);
+
+	return manager;
+
+error_drm_fd:
+	close(manager->drm_fd);
+error_manager:
+	free(manager);
+	return NULL;
+}
+
+struct wlr_linux_drm_syncobj_surface_v1_state *
+wlr_linux_drm_syncobj_v1_get_surface_state(struct wlr_surface *wlr_surface) {
+	struct wlr_linux_drm_syncobj_surface_v1 *surface =
+		surface_from_wlr_surface(wlr_surface);
+	if (surface == NULL) {
+		return NULL;
+	}
+	return &surface->current;
+}