/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ //! The layout thread. Performs layout on the DOM, builds display lists and sends them to be //! painted. #![feature(mpsc_select)] extern crate app_units; extern crate atomic_refcell; extern crate euclid; extern crate fnv; extern crate gfx; extern crate gfx_traits; #[macro_use] extern crate html5ever; extern crate ipc_channel; #[macro_use] extern crate layout; extern crate layout_traits; #[macro_use] extern crate lazy_static; extern crate libc; #[macro_use] extern crate log; extern crate malloc_size_of; extern crate metrics; extern crate msg; extern crate net_traits; extern crate parking_lot; #[macro_use] extern crate profile_traits; extern crate range; extern crate rayon; extern crate script; extern crate script_layout_interface; extern crate script_traits; extern crate selectors; extern crate serde_json; extern crate servo_allocator; extern crate servo_arc; extern crate servo_atoms; extern crate servo_config; extern crate servo_geometry; extern crate servo_url; extern crate style; extern crate style_traits; extern crate webrender_api; mod dom_wrapper; use app_units::Au; use dom_wrapper::{ServoLayoutElement, ServoLayoutDocument, ServoLayoutNode}; use dom_wrapper::drop_style_and_layout_data; use euclid::{Point2D, Rect, Size2D, TypedScale, TypedSize2D}; use fnv::FnvHashMap; use gfx::display_list::{OpaqueNode, WebRenderImageInfo}; use gfx::font; use gfx::font_cache_thread::FontCacheThread; use gfx::font_context; use gfx_traits::{Epoch, node_id_from_scroll_id}; use ipc_channel::ipc::{self, IpcReceiver, IpcSender}; use ipc_channel::router::ROUTER; use layout::animation; use layout::construct::ConstructionResult; use layout::context::LayoutContext; use layout::context::RegisteredPainter; use layout::context::RegisteredPainters; use layout::context::malloc_size_of_persistent_local_context; use layout::display_list::{IndexableText, ToLayout}; use layout::display_list::WebRenderDisplayListConverter; use layout::flow::{Flow, GetBaseFlow, ImmutableFlowUtils, MutableOwnedFlowUtils}; use layout::flow_ref::FlowRef; use layout::incremental::{LayoutDamageComputation, RelayoutMode, SpecialRestyleDamage}; use layout::layout_debug; use layout::parallel; use layout::query::{LayoutRPCImpl, LayoutThreadData, process_content_box_request, process_content_boxes_request}; use layout::query::{process_element_inner_text_query, process_node_geometry_request}; use layout::query::{process_node_scroll_area_request, process_node_scroll_id_request}; use layout::query::{process_offset_parent_query, process_resolved_style_request, process_style_query}; use layout::sequential; use layout::traversal::{ComputeStackingRelativePositions, PreorderFlowTraversal, RecalcStyleAndConstructFlows}; use layout::wrapper::LayoutNodeLayoutData; use layout_traits::LayoutThreadFactory; use libc::c_void; use malloc_size_of::{MallocSizeOf, MallocSizeOfOps}; use metrics::{PaintTimeMetrics, ProfilerMetadataFactory, ProgressiveWebMetric}; use msg::constellation_msg::PipelineId; use msg::constellation_msg::TopLevelBrowsingContextId; use net_traits::image_cache::{ImageCache, UsePlaceholder}; use parking_lot::RwLock; use profile_traits::mem::{self, Report, ReportKind, ReportsChan}; use profile_traits::time::{self, TimerMetadata, profile}; use profile_traits::time::{TimerMetadataFrameType, TimerMetadataReflowType}; use script_layout_interface::message::{Msg, NewLayoutThreadInfo, NodesFromPointQueryType, Reflow}; use script_layout_interface::message::{ReflowComplete, ReflowGoal, ScriptReflow}; use script_layout_interface::rpc::{LayoutRPC, StyleResponse, OffsetParentResponse}; use script_layout_interface::rpc::TextIndexResponse; use script_layout_interface::wrapper_traits::LayoutNode; use script_traits::{ConstellationControlMsg, LayoutControlMsg, LayoutMsg as ConstellationMsg}; use script_traits::{DrawAPaintImageResult, PaintWorkletError}; use script_traits::{ScrollState, UntrustedNodeAddress}; use script_traits::Painter; use selectors::Element; use servo_arc::Arc as ServoArc; use servo_atoms::Atom; use servo_config::opts; use servo_config::prefs::PREFS; use servo_config::resource_files::read_resource_file; use servo_geometry::MaxRect; use servo_url::ServoUrl; use std::borrow::ToOwned; use std::cell::{Cell, RefCell}; use std::collections::HashMap; use std::mem as std_mem; use std::ops::{Deref, DerefMut}; use std::process; use std::sync::{Arc, Mutex, MutexGuard}; use std::sync::atomic::{AtomicUsize, Ordering}; use std::sync::mpsc::{Receiver, Sender, channel}; use std::thread; use style::animation::Animation; use style::context::{QuirksMode, RegisteredSpeculativePainter, RegisteredSpeculativePainters}; use style::context::{SharedStyleContext, StyleSystemOptions, ThreadLocalStyleContextCreationInfo}; use style::dom::{ShowSubtree, ShowSubtreeDataAndPrimaryValues, TElement, TNode}; use style::driver; use style::error_reporting::{NullReporter, RustLogReporter}; use style::invalidation::element::restyle_hints::RestyleHint; use style::logical_geometry::LogicalPoint; use style::media_queries::{Device, MediaList, MediaType}; use style::properties::PropertyId; use style::selector_parser::SnapshotMap; use style::servo::restyle_damage::ServoRestyleDamage; use style::shared_lock::{SharedRwLock, SharedRwLockReadGuard, StylesheetGuards}; use style::stylesheets::{Origin, Stylesheet, DocumentStyleSheet, StylesheetInDocument, UserAgentStylesheets}; use style::stylist::Stylist; use style::thread_state::{self, ThreadState}; use style::timer::Timer; use style::traversal::DomTraversal; use style::traversal_flags::TraversalFlags; use style_traits::CSSPixel; use style_traits::DevicePixel; use style_traits::SpeculativePainter; /// Information needed by the layout thread. pub struct LayoutThread { /// The ID of the pipeline that we belong to. id: PipelineId, /// The ID of the top-level browsing context that we belong to. top_level_browsing_context_id: TopLevelBrowsingContextId, /// The URL of the pipeline that we belong to. url: ServoUrl, /// Performs CSS selector matching and style resolution. stylist: Stylist, /// Is the current reflow of an iframe, as opposed to a root window? is_iframe: bool, /// The port on which we receive messages from the script thread. port: Receiver, /// The port on which we receive messages from the constellation. pipeline_port: Receiver, /// The port on which we receive messages from the font cache thread. font_cache_receiver: Receiver<()>, /// The channel on which the font cache can send messages to us. font_cache_sender: IpcSender<()>, /// The channel on which messages can be sent to the constellation. constellation_chan: IpcSender, /// The channel on which messages can be sent to the script thread. script_chan: IpcSender, /// The channel on which messages can be sent to the time profiler. time_profiler_chan: time::ProfilerChan, /// The channel on which messages can be sent to the memory profiler. mem_profiler_chan: mem::ProfilerChan, /// Reference to the script thread image cache. image_cache: Arc, /// Public interface to the font cache thread. font_cache_thread: FontCacheThread, /// Is this the first reflow in this LayoutThread? first_reflow: Cell, /// The workers that we use for parallel operation. parallel_traversal: Option, /// Flag to indicate whether to use parallel operations parallel_flag: bool, /// Starts at zero, and increased by one every time a layout completes. /// This can be used to easily check for invalid stale data. generation: Cell, /// A channel on which new animations that have been triggered by style recalculation can be /// sent. new_animations_sender: Sender, /// Receives newly-discovered animations. new_animations_receiver: Receiver, /// The number of Web fonts that have been requested but not yet loaded. outstanding_web_fonts: Arc, /// The root of the flow tree. root_flow: RefCell>, /// The document-specific shared lock used for author-origin stylesheets document_shared_lock: Option, /// The list of currently-running animations. running_animations: ServoArc>>>, /// The list of animations that have expired since the last style recalculation. expired_animations: ServoArc>>>, /// A counter for epoch messages epoch: Cell, /// The size of the viewport. This may be different from the size of the screen due to viewport /// constraints. viewport_size: Size2D, /// A mutex to allow for fast, read-only RPC of layout's internal data /// structures, while still letting the LayoutThread modify them. /// /// All the other elements of this struct are read-only. rw_data: Arc>, webrender_image_cache: Arc>>, /// The executors for paint worklets. registered_painters: RegisteredPaintersImpl, /// Webrender interface. webrender_api: webrender_api::RenderApi, /// Webrender document. webrender_document: webrender_api::DocumentId, /// The timer object to control the timing of the animations. This should /// only be a test-mode timer during testing for animations. timer: Timer, // Number of layout threads. This is copied from `servo_config::opts`, but we'd // rather limit the dependency on that module here. layout_threads: usize, /// Paint time metrics. paint_time_metrics: PaintTimeMetrics, } impl LayoutThreadFactory for LayoutThread { type Message = Msg; /// Spawns a new layout thread. fn create(id: PipelineId, top_level_browsing_context_id: TopLevelBrowsingContextId, url: ServoUrl, is_iframe: bool, chan: (Sender, Receiver), pipeline_port: IpcReceiver, constellation_chan: IpcSender, script_chan: IpcSender, image_cache: Arc, font_cache_thread: FontCacheThread, time_profiler_chan: time::ProfilerChan, mem_profiler_chan: mem::ProfilerChan, content_process_shutdown_chan: Option>, webrender_api_sender: webrender_api::RenderApiSender, webrender_document: webrender_api::DocumentId, layout_threads: usize, paint_time_metrics: PaintTimeMetrics) { thread::Builder::new().name(format!("LayoutThread {:?}", id)).spawn(move || { thread_state::initialize(ThreadState::LAYOUT); // In order to get accurate crash reports, we install the top-level bc id. TopLevelBrowsingContextId::install(top_level_browsing_context_id); { // Ensures layout thread is destroyed before we send shutdown message let sender = chan.0; let layout = LayoutThread::new(id, top_level_browsing_context_id, url, is_iframe, chan.1, pipeline_port, constellation_chan, script_chan, image_cache.clone(), font_cache_thread, time_profiler_chan, mem_profiler_chan.clone(), webrender_api_sender, webrender_document, layout_threads, paint_time_metrics); let reporter_name = format!("layout-reporter-{}", id); mem_profiler_chan.run_with_memory_reporting(|| { layout.start(); }, reporter_name, sender, Msg::CollectReports); } if let Some(content_process_shutdown_chan) = content_process_shutdown_chan { let _ = content_process_shutdown_chan.send(()); } }).expect("Thread spawning failed"); } } struct ScriptReflowResult { script_reflow: ScriptReflow, result: RefCell>, } impl Deref for ScriptReflowResult { type Target = ScriptReflow; fn deref(&self) -> &ScriptReflow { &self.script_reflow } } impl ScriptReflowResult { fn new(script_reflow: ScriptReflow) -> ScriptReflowResult { ScriptReflowResult { script_reflow: script_reflow, result: RefCell::new(Some(Default::default())), } } } impl Drop for ScriptReflowResult { fn drop(&mut self) { self.script_reflow.script_join_chan.send( self.result .borrow_mut() .take() .unwrap()).unwrap(); } } /// The `LayoutThread` `rw_data` lock must remain locked until the first reflow, /// as RPC calls don't make sense until then. Use this in combination with /// `LayoutThread::lock_rw_data` and `LayoutThread::return_rw_data`. pub enum RWGuard<'a> { /// If the lock was previously held, from when the thread started. Held(MutexGuard<'a, LayoutThreadData>), /// If the lock was just used, and has been returned since there has been /// a reflow already. Used(MutexGuard<'a, LayoutThreadData>), } impl<'a> Deref for RWGuard<'a> { type Target = LayoutThreadData; fn deref(&self) -> &LayoutThreadData { match *self { RWGuard::Held(ref x) => &**x, RWGuard::Used(ref x) => &**x, } } } impl<'a> DerefMut for RWGuard<'a> { fn deref_mut(&mut self) -> &mut LayoutThreadData { match *self { RWGuard::Held(ref mut x) => &mut **x, RWGuard::Used(ref mut x) => &mut **x, } } } struct RwData<'a, 'b: 'a> { rw_data: &'b Arc>, possibly_locked_rw_data: &'a mut Option>, } impl<'a, 'b: 'a> RwData<'a, 'b> { /// If no reflow has happened yet, this will just return the lock in /// `possibly_locked_rw_data`. Otherwise, it will acquire the `rw_data` lock. /// /// If you do not wish RPCs to remain blocked, just drop the `RWGuard` /// returned from this function. If you _do_ wish for them to remain blocked, /// use `block`. fn lock(&mut self) -> RWGuard<'b> { match self.possibly_locked_rw_data.take() { None => RWGuard::Used(self.rw_data.lock().unwrap()), Some(x) => RWGuard::Held(x), } } } fn add_font_face_rules(stylesheet: &Stylesheet, guard: &SharedRwLockReadGuard, device: &Device, font_cache_thread: &FontCacheThread, font_cache_sender: &IpcSender<()>, outstanding_web_fonts_counter: &Arc) { if opts::get().load_webfonts_synchronously { let (sender, receiver) = ipc::channel().unwrap(); stylesheet.effective_font_face_rules(&device, guard, |rule| { if let Some(font_face) = rule.font_face() { let effective_sources = font_face.effective_sources(); font_cache_thread.add_web_font(font_face.family().clone(), effective_sources, sender.clone()); receiver.recv().unwrap(); } }) } else { stylesheet.effective_font_face_rules(&device, guard, |rule| { if let Some(font_face) = rule.font_face() { let effective_sources = font_face.effective_sources(); outstanding_web_fonts_counter.fetch_add(1, Ordering::SeqCst); font_cache_thread.add_web_font(font_face.family().clone(), effective_sources, (*font_cache_sender).clone()); } }) } } impl LayoutThread { /// Creates a new `LayoutThread` structure. fn new(id: PipelineId, top_level_browsing_context_id: TopLevelBrowsingContextId, url: ServoUrl, is_iframe: bool, port: Receiver, pipeline_port: IpcReceiver, constellation_chan: IpcSender, script_chan: IpcSender, image_cache: Arc, font_cache_thread: FontCacheThread, time_profiler_chan: time::ProfilerChan, mem_profiler_chan: mem::ProfilerChan, webrender_api_sender: webrender_api::RenderApiSender, webrender_document: webrender_api::DocumentId, layout_threads: usize, paint_time_metrics: PaintTimeMetrics) -> LayoutThread { // The device pixel ratio is incorrect (it does not have the hidpi value), // but it will be set correctly when the initial reflow takes place. let device = Device::new( MediaType::screen(), opts::get().initial_window_size.to_f32() * TypedScale::new(1.0), TypedScale::new(opts::get().device_pixels_per_px.unwrap_or(1.0))); let workers = rayon::ThreadPoolBuilder::new().num_threads(layout_threads) .start_handler(|_| thread_state::initialize_layout_worker_thread()) .build(); let parallel_traversal = if layout_threads > 1 { Some(workers.expect("ThreadPool creation failed")) } else { None }; debug!("Possible layout Threads: {}", layout_threads); // Create the channel on which new animations can be sent. let (new_animations_sender, new_animations_receiver) = channel(); // Proxy IPC messages from the pipeline to the layout thread. let pipeline_receiver = ROUTER.route_ipc_receiver_to_new_mpsc_receiver(pipeline_port); // Ask the router to proxy IPC messages from the font cache thread to the layout thread. let (ipc_font_cache_sender, ipc_font_cache_receiver) = ipc::channel().unwrap(); let font_cache_receiver = ROUTER.route_ipc_receiver_to_new_mpsc_receiver(ipc_font_cache_receiver); LayoutThread { id: id, top_level_browsing_context_id: top_level_browsing_context_id, url: url, is_iframe: is_iframe, port: port, pipeline_port: pipeline_receiver, script_chan: script_chan.clone(), constellation_chan: constellation_chan.clone(), time_profiler_chan: time_profiler_chan, mem_profiler_chan: mem_profiler_chan, registered_painters: RegisteredPaintersImpl(FnvHashMap::default()), image_cache: image_cache.clone(), font_cache_thread: font_cache_thread, first_reflow: Cell::new(true), font_cache_receiver: font_cache_receiver, font_cache_sender: ipc_font_cache_sender, parallel_traversal: parallel_traversal, parallel_flag: true, generation: Cell::new(0), new_animations_sender: new_animations_sender, new_animations_receiver: new_animations_receiver, outstanding_web_fonts: Arc::new(AtomicUsize::new(0)), root_flow: RefCell::new(None), document_shared_lock: None, running_animations: ServoArc::new(RwLock::new(FnvHashMap::default())), expired_animations: ServoArc::new(RwLock::new(FnvHashMap::default())), epoch: Cell::new(Epoch(0)), viewport_size: Size2D::new(Au(0), Au(0)), webrender_api: webrender_api_sender.create_api(), webrender_document, stylist: Stylist::new(device, QuirksMode::NoQuirks), rw_data: Arc::new(Mutex::new( LayoutThreadData { constellation_chan: constellation_chan, display_list: None, indexable_text: IndexableText::default(), content_box_response: None, content_boxes_response: Vec::new(), client_rect_response: Rect::zero(), scroll_id_response: None, scroll_area_response: Rect::zero(), resolved_style_response: String::new(), offset_parent_response: OffsetParentResponse::empty(), style_response: StyleResponse(None), scroll_offsets: HashMap::new(), text_index_response: TextIndexResponse(None), nodes_from_point_response: vec![], element_inner_text_response: String::new(), })), webrender_image_cache: Arc::new(RwLock::new(FnvHashMap::default())), timer: if PREFS.get("layout.animations.test.enabled") .as_boolean().unwrap_or(false) { Timer::test_mode() } else { Timer::new() }, layout_threads: layout_threads, paint_time_metrics: paint_time_metrics, } } /// Starts listening on the port. fn start(mut self) { let rw_data = self.rw_data.clone(); let mut possibly_locked_rw_data = Some(rw_data.lock().unwrap()); let mut rw_data = RwData { rw_data: &rw_data, possibly_locked_rw_data: &mut possibly_locked_rw_data, }; while self.handle_request(&mut rw_data) { // Loop indefinitely. } } // Create a layout context for use in building display lists, hit testing, &c. fn build_layout_context<'a>(&'a self, guards: StylesheetGuards<'a>, script_initiated_layout: bool, snapshot_map: &'a SnapshotMap) -> LayoutContext<'a> { let thread_local_style_context_creation_data = ThreadLocalStyleContextCreationInfo::new(self.new_animations_sender.clone()); LayoutContext { id: self.id, style_context: SharedStyleContext { stylist: &self.stylist, options: StyleSystemOptions::default(), guards: guards, visited_styles_enabled: false, running_animations: self.running_animations.clone(), expired_animations: self.expired_animations.clone(), registered_speculative_painters: &self.registered_painters, local_context_creation_data: Mutex::new(thread_local_style_context_creation_data), timer: self.timer.clone(), traversal_flags: TraversalFlags::empty(), snapshot_map: snapshot_map, }, image_cache: self.image_cache.clone(), font_cache_thread: Mutex::new(self.font_cache_thread.clone()), webrender_image_cache: self.webrender_image_cache.clone(), pending_images: if script_initiated_layout { Some(Mutex::new(vec![])) } else { None }, newly_transitioning_nodes: if script_initiated_layout { Some(Mutex::new(vec![])) } else { None }, registered_painters: &self.registered_painters, } } /// Receives and dispatches messages from the script and constellation threads fn handle_request<'a, 'b>(&mut self, possibly_locked_rw_data: &mut RwData<'a, 'b>) -> bool { enum Request { FromPipeline(LayoutControlMsg), FromScript(Msg), FromFontCache, } let request = { let port_from_script = &self.port; let port_from_pipeline = &self.pipeline_port; let port_from_font_cache = &self.font_cache_receiver; select! { msg = port_from_pipeline.recv() => { Request::FromPipeline(msg.unwrap()) }, msg = port_from_script.recv() => { Request::FromScript(msg.unwrap()) }, msg = port_from_font_cache.recv() => { msg.unwrap(); Request::FromFontCache } } }; match request { Request::FromPipeline(LayoutControlMsg::SetScrollStates(new_scroll_states)) => { self.handle_request_helper(Msg::SetScrollStates(new_scroll_states), possibly_locked_rw_data) }, Request::FromPipeline(LayoutControlMsg::TickAnimations) => { self.handle_request_helper(Msg::TickAnimations, possibly_locked_rw_data) }, Request::FromPipeline(LayoutControlMsg::GetCurrentEpoch(sender)) => { self.handle_request_helper(Msg::GetCurrentEpoch(sender), possibly_locked_rw_data) }, Request::FromPipeline(LayoutControlMsg::GetWebFontLoadState(sender)) => { self.handle_request_helper(Msg::GetWebFontLoadState(sender), possibly_locked_rw_data) }, Request::FromPipeline(LayoutControlMsg::ExitNow) => { self.handle_request_helper(Msg::ExitNow, possibly_locked_rw_data) }, Request::FromPipeline(LayoutControlMsg::PaintMetric(epoch, paint_time)) => { self.paint_time_metrics.maybe_set_metric(epoch, paint_time); true }, Request::FromScript(msg) => { self.handle_request_helper(msg, possibly_locked_rw_data) }, Request::FromFontCache => { let _rw_data = possibly_locked_rw_data.lock(); self.outstanding_web_fonts.fetch_sub(1, Ordering::SeqCst); font_context::invalidate_font_caches(); self.script_chan.send(ConstellationControlMsg::WebFontLoaded(self.id)).unwrap(); true }, } } /// Receives and dispatches messages from other threads. fn handle_request_helper<'a, 'b>( &mut self, request: Msg, possibly_locked_rw_data: &mut RwData<'a, 'b>, ) -> bool { match request { Msg::AddStylesheet(stylesheet, before_stylesheet) => { let guard = stylesheet.shared_lock.read(); self.handle_add_stylesheet(&stylesheet, &guard); match before_stylesheet { Some(insertion_point) => { self.stylist.insert_stylesheet_before( DocumentStyleSheet(stylesheet.clone()), DocumentStyleSheet(insertion_point), &guard, ) } None => { self.stylist.append_stylesheet( DocumentStyleSheet(stylesheet.clone()), &guard, ) } } } Msg::RemoveStylesheet(stylesheet) => { let guard = stylesheet.shared_lock.read(); self.stylist.remove_stylesheet( DocumentStyleSheet(stylesheet.clone()), &guard, ); } Msg::SetQuirksMode(mode) => self.handle_set_quirks_mode(mode), Msg::GetRPC(response_chan) => { response_chan.send( Box::new(LayoutRPCImpl(self.rw_data.clone())) as Box ).unwrap(); }, Msg::Reflow(data) => { let mut data = ScriptReflowResult::new(data); profile(time::ProfilerCategory::LayoutPerform, self.profiler_metadata(), self.time_profiler_chan.clone(), || self.handle_reflow(&mut data, possibly_locked_rw_data)); }, Msg::TickAnimations => self.tick_all_animations(possibly_locked_rw_data), Msg::SetScrollStates(new_scroll_states) => { self.set_scroll_states(new_scroll_states, possibly_locked_rw_data); } Msg::UpdateScrollStateFromScript(state) => { let mut rw_data = possibly_locked_rw_data.lock(); rw_data.scroll_offsets.insert(state.scroll_id, state.scroll_offset); let point = Point2D::new(-state.scroll_offset.x, -state.scroll_offset.y); let mut txn = webrender_api::Transaction::new(); txn.scroll_node_with_id( webrender_api::LayoutPoint::from_untyped(&point), state.scroll_id, webrender_api::ScrollClamping::ToContentBounds ); self.webrender_api.send_transaction(self.webrender_document, txn); } Msg::ReapStyleAndLayoutData(dead_data) => { unsafe { drop_style_and_layout_data(dead_data) } } Msg::CollectReports(reports_chan) => { self.collect_reports(reports_chan, possibly_locked_rw_data); }, Msg::GetCurrentEpoch(sender) => { let _rw_data = possibly_locked_rw_data.lock(); sender.send(self.epoch.get()).unwrap(); }, Msg::AdvanceClockMs(how_many, do_tick) => { self.handle_advance_clock_ms(how_many, possibly_locked_rw_data, do_tick); } Msg::GetWebFontLoadState(sender) => { let _rw_data = possibly_locked_rw_data.lock(); let outstanding_web_fonts = self.outstanding_web_fonts.load(Ordering::SeqCst); sender.send(outstanding_web_fonts != 0).unwrap(); }, Msg::CreateLayoutThread(info) => { self.create_layout_thread(info) } Msg::SetFinalUrl(final_url) => { self.url = final_url; }, Msg::RegisterPaint(name, mut properties, painter) => { debug!("Registering the painter"); let properties = properties.drain(..) .filter_map(|name| PropertyId::parse(&*name) .ok().map(|id| (name.clone(), id))) .filter(|&(_, ref id)| id.as_shorthand().is_err()) .collect(); let registered_painter = RegisteredPainterImpl { name: name.clone(), properties: properties, painter: painter, }; self.registered_painters.0.insert(name, registered_painter); }, Msg::PrepareToExit(response_chan) => { self.prepare_to_exit(response_chan); return false }, Msg::ExitNow => { debug!("layout: ExitNow received"); self.exit_now(); return false }, Msg::SetNavigationStart(time) => { self.paint_time_metrics.set_navigation_start(time); }, } true } fn collect_reports<'a, 'b>(&self, reports_chan: ReportsChan, possibly_locked_rw_data: &mut RwData<'a, 'b>) { let mut reports = vec![]; // Servo uses vanilla jemalloc, which doesn't have a // malloc_enclosing_size_of function. let mut ops = MallocSizeOfOps::new(::servo_allocator::usable_size, None, None); // FIXME(njn): Just measuring the display tree for now. let rw_data = possibly_locked_rw_data.lock(); let display_list = rw_data.display_list.as_ref(); let formatted_url = &format!("url({})", self.url); reports.push(Report { path: path![formatted_url, "layout-thread", "display-list"], kind: ReportKind::ExplicitJemallocHeapSize, size: display_list.map_or(0, |sc| sc.size_of(&mut ops)), }); reports.push(Report { path: path![formatted_url, "layout-thread", "stylist"], kind: ReportKind::ExplicitJemallocHeapSize, size: self.stylist.size_of(&mut ops), }); // The LayoutThread has data in Persistent TLS... reports.push(Report { path: path![formatted_url, "layout-thread", "local-context"], kind: ReportKind::ExplicitJemallocHeapSize, size: malloc_size_of_persistent_local_context(&mut ops), }); reports_chan.send(reports); } fn create_layout_thread(&self, info: NewLayoutThreadInfo) { LayoutThread::create(info.id, self.top_level_browsing_context_id, info.url.clone(), info.is_parent, info.layout_pair, info.pipeline_port, info.constellation_chan, info.script_chan.clone(), info.image_cache.clone(), self.font_cache_thread.clone(), self.time_profiler_chan.clone(), self.mem_profiler_chan.clone(), info.content_process_shutdown_chan, self.webrender_api.clone_sender(), self.webrender_document, info.layout_threads, info.paint_time_metrics); } /// Enters a quiescent state in which no new messages will be processed until an `ExitNow` is /// received. A pong is immediately sent on the given response channel. fn prepare_to_exit(&mut self, response_chan: Sender<()>) { response_chan.send(()).unwrap(); loop { match self.port.recv().unwrap() { Msg::ReapStyleAndLayoutData(dead_data) => { unsafe { drop_style_and_layout_data(dead_data) } } Msg::ExitNow => { debug!("layout thread is exiting..."); self.exit_now(); break } Msg::CollectReports(_) => { // Just ignore these messages at this point. } _ => { panic!("layout: unexpected message received after `PrepareToExitMsg`") } } } } /// Shuts down the layout thread now. If there are any DOM nodes left, layout will now (safely) /// crash. fn exit_now(&mut self) { // Drop the root flow explicitly to avoid holding style data, such as // rule nodes. The `Stylist` checks when it is dropped that all rule // nodes have been GCed, so we want drop anyone who holds them first. self.root_flow.borrow_mut().take(); // Drop the rayon threadpool if present. let _ = self.parallel_traversal.take(); } fn handle_add_stylesheet( &self, stylesheet: &Stylesheet, guard: &SharedRwLockReadGuard, ) { // Find all font-face rules and notify the font cache of them. // GWTODO: Need to handle unloading web fonts. if stylesheet.is_effective_for_device(self.stylist.device(), &guard) { add_font_face_rules(&*stylesheet, &guard, self.stylist.device(), &self.font_cache_thread, &self.font_cache_sender, &self.outstanding_web_fonts); } } /// Advances the animation clock of the document. fn handle_advance_clock_ms<'a, 'b>(&mut self, how_many_ms: i32, possibly_locked_rw_data: &mut RwData<'a, 'b>, tick_animations: bool) { self.timer.increment(how_many_ms as f64 / 1000.0); if tick_animations { self.tick_all_animations(possibly_locked_rw_data); } } /// Sets quirks mode for the document, causing the quirks mode stylesheet to be used. fn handle_set_quirks_mode<'a, 'b>(&mut self, quirks_mode: QuirksMode) { self.stylist.set_quirks_mode(quirks_mode); } fn try_get_layout_root(&self, node: N) -> Option { let result = node.mutate_layout_data()?.flow_construction_result.get(); let mut flow = match result { ConstructionResult::Flow(mut flow, abs_descendants) => { // Note: Assuming that the root has display 'static' (as per // CSS Section 9.3.1). Otherwise, if it were absolutely // positioned, it would return a reference to itself in // `abs_descendants` and would lead to a circular reference. // Set Root as CB for any remaining absolute descendants. flow.set_absolute_descendants(abs_descendants); flow } _ => return None, }; FlowRef::deref_mut(&mut flow).mark_as_root(); Some(flow) } /// Performs layout constraint solving. /// /// This corresponds to `Reflow()` in Gecko and `layout()` in WebKit/Blink and should be /// benchmarked against those two. It is marked `#[inline(never)]` to aid profiling. #[inline(never)] fn solve_constraints(layout_root: &mut Flow, layout_context: &LayoutContext) { let _scope = layout_debug_scope!("solve_constraints"); sequential::reflow(layout_root, layout_context, RelayoutMode::Incremental); } /// Performs layout constraint solving in parallel. /// /// This corresponds to `Reflow()` in Gecko and `layout()` in WebKit/Blink and should be /// benchmarked against those two. It is marked `#[inline(never)]` to aid profiling. #[inline(never)] fn solve_constraints_parallel(traversal: &rayon::ThreadPool, layout_root: &mut Flow, profiler_metadata: Option, time_profiler_chan: time::ProfilerChan, layout_context: &LayoutContext) { let _scope = layout_debug_scope!("solve_constraints_parallel"); // NOTE: this currently computes borders, so any pruning should separate that // operation out. parallel::reflow(layout_root, profiler_metadata, time_profiler_chan, layout_context, traversal); } /// Computes the stacking-relative positions of all flows and, if the painting is dirty and the /// reflow type need it, builds the display list. fn compute_abs_pos_and_build_display_list(&self, data: &Reflow, reflow_goal: &ReflowGoal, document: Option<&ServoLayoutDocument>, layout_root: &mut Flow, layout_context: &mut LayoutContext, rw_data: &mut LayoutThreadData) { let writing_mode = layout_root.base().writing_mode; let (metadata, sender) = (self.profiler_metadata(), self.time_profiler_chan.clone()); profile(time::ProfilerCategory::LayoutDispListBuild, metadata.clone(), sender.clone(), || { layout_root.mut_base().stacking_relative_position = LogicalPoint::zero(writing_mode).to_physical(writing_mode, self.viewport_size).to_vector(); layout_root.mut_base().clip = data.page_clip_rect; let traversal = ComputeStackingRelativePositions { layout_context: layout_context }; traversal.traverse(layout_root); if layout_root.base().restyle_damage.contains(ServoRestyleDamage::REPAINT) || rw_data.display_list.is_none() { if reflow_goal.needs_display_list() { let mut build_state = sequential::build_display_list_for_subtree(layout_root, layout_context); debug!("Done building display list."); let root_size = { let root_flow = layout_root.base(); if self.stylist.viewport_constraints().is_some() { root_flow.position.size.to_physical(root_flow.writing_mode) } else { root_flow.overflow.scroll.size } }; let origin = Rect::new(Point2D::new(Au(0), Au(0)), root_size).to_layout(); build_state.root_stacking_context.bounds = origin; build_state.root_stacking_context.overflow = origin; if !build_state.iframe_sizes.is_empty() { // build_state.iframe_sizes is only used here, so its okay to replace // it with an empty vector let iframe_sizes = std::mem::replace(&mut build_state.iframe_sizes, vec![]); let msg = ConstellationMsg::IFrameSizes(iframe_sizes); if let Err(e) = self.constellation_chan.send(msg) { warn!("Layout resize to constellation failed ({}).", e); } } rw_data.indexable_text = std::mem::replace( &mut build_state.indexable_text, IndexableText::default()); rw_data.display_list = Some(Arc::new(build_state.to_display_list())); } } if !reflow_goal.needs_display() { // Defer the paint step until the next ForDisplay. // // We need to tell the document about this so it doesn't // incorrectly suppress reflows. See #13131. document.expect("No document in a non-display reflow?").needs_paint_from_layout(); return; } if let Some(document) = document { document.will_paint(); } let display_list = (*rw_data.display_list.as_ref().unwrap()).clone(); if opts::get().dump_display_list { display_list.print(); } if opts::get().dump_display_list_json { println!("{}", serde_json::to_string_pretty(&display_list).unwrap()); } debug!("Layout done!"); // TODO: Avoid the temporary conversion and build webrender sc/dl directly! let builder = rw_data.display_list.as_ref().unwrap().convert_to_webrender(self.id); let viewport_size = Size2D::new(self.viewport_size.width.to_f32_px(), self.viewport_size.height.to_f32_px()); let mut epoch = self.epoch.get(); epoch.next(); self.epoch.set(epoch); let viewport_size = webrender_api::LayoutSize::from_untyped(&viewport_size); // Observe notifications about rendered frames if needed right before // sending the display list to WebRender in order to set time related // Progressive Web Metrics. self.paint_time_metrics.maybe_observe_paint_time(self, epoch, &*display_list); let mut txn = webrender_api::Transaction::new(); txn.set_display_list( webrender_api::Epoch(epoch.0), Some(get_root_flow_background_color(layout_root)), viewport_size, builder.finalize(), true); txn.generate_frame(); self.webrender_api.send_transaction(self.webrender_document, txn); }); } /// The high-level routine that performs layout threads. fn handle_reflow<'a, 'b>(&mut self, data: &mut ScriptReflowResult, possibly_locked_rw_data: &mut RwData<'a, 'b>) { let document = unsafe { ServoLayoutNode::new(&data.document) }; let document = document.as_document().unwrap(); // Parallelize if there's more than 750 objects based on rzambre's suggestion // https://github.com/servo/servo/issues/10110 self.parallel_flag = self.layout_threads > 1 && data.dom_count > 750; debug!("layout: received layout request for: {}", self.url); debug!("Number of objects in DOM: {}", data.dom_count); debug!("layout: parallel? {}", self.parallel_flag); let mut rw_data = possibly_locked_rw_data.lock(); let element = match document.root_element() { None => { // Since we cannot compute anything, give spec-required placeholders. debug!("layout: No root node: bailing"); match data.reflow_goal { ReflowGoal::ContentBoxQuery(_) => { rw_data.content_box_response = None; }, ReflowGoal::ContentBoxesQuery(_) => { rw_data.content_boxes_response = Vec::new(); }, ReflowGoal::NodesFromPointQuery(..) => { rw_data.nodes_from_point_response = Vec::new(); }, ReflowGoal::NodeGeometryQuery(_) => { rw_data.client_rect_response = Rect::zero(); }, ReflowGoal::NodeScrollGeometryQuery(_) => { rw_data.scroll_area_response = Rect::zero(); }, ReflowGoal::NodeScrollIdQuery(_) => { rw_data.scroll_id_response = None; }, ReflowGoal::ResolvedStyleQuery(_, _, _) => { rw_data.resolved_style_response = String::new(); }, ReflowGoal::OffsetParentQuery(_) => { rw_data.offset_parent_response = OffsetParentResponse::empty(); }, ReflowGoal::StyleQuery(_) => { rw_data.style_response = StyleResponse(None); }, ReflowGoal::TextIndexQuery(..) => { rw_data.text_index_response = TextIndexResponse(None); } ReflowGoal::ElementInnerTextQuery(_) => { rw_data.element_inner_text_response = String::new(); }, ReflowGoal::Full | ReflowGoal:: TickAnimations => {} } return; }, Some(x) => x, }; debug!("layout: processing reflow request for: {:?} ({}) (query={:?})", element, self.url, data.reflow_goal); trace!("{:?}", ShowSubtree(element.as_node())); let initial_viewport = data.window_size.initial_viewport; let device_pixel_ratio = data.window_size.device_pixel_ratio; let old_viewport_size = self.viewport_size; let current_screen_size = Size2D::new(Au::from_f32_px(initial_viewport.width), Au::from_f32_px(initial_viewport.height)); // Calculate the actual viewport as per DEVICE-ADAPT ยง 6 // If the entire flow tree is invalid, then it will be reflowed anyhow. let document_shared_lock = document.style_shared_lock(); self.document_shared_lock = Some(document_shared_lock.clone()); let author_guard = document_shared_lock.read(); let ua_stylesheets = &*UA_STYLESHEETS; let ua_or_user_guard = ua_stylesheets.shared_lock.read(); let guards = StylesheetGuards { author: &author_guard, ua_or_user: &ua_or_user_guard, }; let had_used_viewport_units = self.stylist.device().used_viewport_units(); let device = Device::new(MediaType::screen(), initial_viewport, device_pixel_ratio); let sheet_origins_affected_by_device_change = self.stylist.set_device(device, &guards); self.stylist.force_stylesheet_origins_dirty(sheet_origins_affected_by_device_change); self.viewport_size = self.stylist.viewport_constraints().map_or(current_screen_size, |constraints| { debug!("Viewport constraints: {:?}", constraints); // other rules are evaluated against the actual viewport Size2D::new(Au::from_f32_px(constraints.size.width), Au::from_f32_px(constraints.size.height)) }); let viewport_size_changed = self.viewport_size != old_viewport_size; if viewport_size_changed { if let Some(constraints) = self.stylist.viewport_constraints() { // let the constellation know about the viewport constraints rw_data.constellation_chan .send(ConstellationMsg::ViewportConstrained(self.id, constraints.clone())) .unwrap(); } if had_used_viewport_units { if let Some(mut data) = element.mutate_data() { data.hint.insert(RestyleHint::recascade_subtree()); } } } { if self.first_reflow.get() { debug!("First reflow, rebuilding user and UA rules"); for stylesheet in &ua_stylesheets.user_or_user_agent_stylesheets { self.stylist.append_stylesheet(stylesheet.clone(), &ua_or_user_guard); self.handle_add_stylesheet(&stylesheet.0, &ua_or_user_guard); } if self.stylist.quirks_mode() != QuirksMode::NoQuirks { self.stylist.append_stylesheet( ua_stylesheets.quirks_mode_stylesheet.clone(), &ua_or_user_guard, ); self.handle_add_stylesheet( &ua_stylesheets.quirks_mode_stylesheet.0, &ua_or_user_guard, ); } } if data.stylesheets_changed { debug!("Doc sheets changed, flushing author sheets too"); self.stylist.force_stylesheet_origins_dirty(Origin::Author.into()); } } if viewport_size_changed { if let Some(mut flow) = self.try_get_layout_root(element.as_node()) { LayoutThread::reflow_all_nodes(FlowRef::deref_mut(&mut flow)); } } let restyles = document.drain_pending_restyles(); debug!("Draining restyles: {}", restyles.len()); let mut map = SnapshotMap::new(); let elements_with_snapshot: Vec<_> = restyles .iter() .filter(|r| r.1.snapshot.is_some()) .map(|r| r.0) .collect(); for (el, restyle) in restyles { // Propagate the descendant bit up the ancestors. Do this before // the restyle calculation so that we can also do it for new // unstyled nodes, which the descendants bit helps us find. if let Some(parent) = el.parent_element() { unsafe { parent.note_dirty_descendant() }; } // If we haven't styled this node yet, we don't need to track a // restyle. let style_data = match el.get_data() { Some(d) => d, None => { unsafe { el.unset_snapshot_flags() }; continue; } }; if let Some(s) = restyle.snapshot { unsafe { el.set_has_snapshot() }; map.insert(el.as_node().opaque(), s); } let mut style_data = style_data.borrow_mut(); // Stash the data on the element for processing by the style system. style_data.hint.insert(restyle.hint.into()); style_data.damage = restyle.damage; debug!("Noting restyle for {:?}: {:?}", el, style_data); } self.stylist.flush(&guards, Some(element), Some(&map)); // Create a layout context for use throughout the following passes. let mut layout_context = self.build_layout_context(guards.clone(), true, &map); let thread_pool = if self.parallel_flag { self.parallel_traversal.as_ref() } else { None }; let traversal = RecalcStyleAndConstructFlows::new(layout_context); let token = { let shared = >::shared_context(&traversal); RecalcStyleAndConstructFlows::pre_traverse(element, shared) }; if token.should_traverse() { // Recalculate CSS styles and rebuild flows and fragments. profile(time::ProfilerCategory::LayoutStyleRecalc, self.profiler_metadata(), self.time_profiler_chan.clone(), || { // Perform CSS selector matching and flow construction. driver::traverse_dom::( &traversal, token, thread_pool, ); }); // TODO(pcwalton): Measure energy usage of text shaping, perhaps? let text_shaping_time = (font::get_and_reset_text_shaping_performance_counter() as u64) / (self.layout_threads as u64); time::send_profile_data(time::ProfilerCategory::LayoutTextShaping, self.profiler_metadata(), &self.time_profiler_chan, 0, text_shaping_time, 0, 0); // Retrieve the (possibly rebuilt) root flow. *self.root_flow.borrow_mut() = self.try_get_layout_root(element.as_node()); } for element in elements_with_snapshot { unsafe { element.unset_snapshot_flags() } } layout_context = traversal.destroy(); if opts::get().dump_style_tree { println!("{:?}", ShowSubtreeDataAndPrimaryValues(element.as_node())); } if opts::get().dump_rule_tree { layout_context.style_context.stylist.rule_tree().dump_stdout(&guards); } // GC the rule tree if some heuristics are met. unsafe { layout_context.style_context.stylist.rule_tree().maybe_gc(); } // Perform post-style recalculation layout passes. if let Some(mut root_flow) = self.root_flow.borrow().clone() { self.perform_post_style_recalc_layout_passes(&mut root_flow, &data.reflow_info, &data.reflow_goal, Some(&document), &mut rw_data, &mut layout_context); } self.first_reflow.set(false); self.respond_to_query_if_necessary(&data.reflow_goal, &mut *rw_data, &mut layout_context, data.result.borrow_mut().as_mut().unwrap()); } fn respond_to_query_if_necessary(&self, reflow_goal: &ReflowGoal, rw_data: &mut LayoutThreadData, context: &mut LayoutContext, reflow_result: &mut ReflowComplete) { let pending_images = match context.pending_images { Some(ref pending) => std_mem::replace(&mut *pending.lock().unwrap(), vec![]), None => vec![], }; reflow_result.pending_images = pending_images; let newly_transitioning_nodes = match context.newly_transitioning_nodes { Some(ref nodes) => std_mem::replace(&mut *nodes.lock().unwrap(), vec![]), None => vec![], }; reflow_result.newly_transitioning_nodes = newly_transitioning_nodes; let mut root_flow = match self.root_flow.borrow().clone() { Some(root_flow) => root_flow, None => return, }; let root_flow = FlowRef::deref_mut(&mut root_flow); match *reflow_goal { ReflowGoal::ContentBoxQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.content_box_response = process_content_box_request(node, root_flow); }, ReflowGoal::ContentBoxesQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.content_boxes_response = process_content_boxes_request(node, root_flow); }, ReflowGoal::TextIndexQuery(node, point_in_node) => { let node = unsafe { ServoLayoutNode::new(&node) }; let opaque_node = node.opaque(); let point_in_node = Point2D::new( Au::from_f32_px(point_in_node.x), Au::from_f32_px(point_in_node.y) ); rw_data.text_index_response = TextIndexResponse( rw_data.indexable_text.text_index(opaque_node, point_in_node) ); }, ReflowGoal::NodeGeometryQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.client_rect_response = process_node_geometry_request(node, root_flow); }, ReflowGoal::NodeScrollGeometryQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.scroll_area_response = process_node_scroll_area_request(node, root_flow); }, ReflowGoal::NodeScrollIdQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.scroll_id_response = Some(process_node_scroll_id_request(self.id, node)); }, ReflowGoal::ResolvedStyleQuery(node, ref pseudo, ref property) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.resolved_style_response = process_resolved_style_request(context, node, pseudo, property, root_flow); }, ReflowGoal::OffsetParentQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.offset_parent_response = process_offset_parent_query(node, root_flow); }, ReflowGoal::StyleQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.style_response = process_style_query(node); }, ReflowGoal::NodesFromPointQuery(client_point, ref reflow_goal) => { let mut flags = match reflow_goal { &NodesFromPointQueryType::Topmost => webrender_api::HitTestFlags::empty(), &NodesFromPointQueryType::All => webrender_api::HitTestFlags::FIND_ALL, }; // The point we get is not relative to the entire WebRender scene, but to this // particular pipeline, so we need to tell WebRender about that. flags.insert(webrender_api::HitTestFlags::POINT_RELATIVE_TO_PIPELINE_VIEWPORT); let client_point = webrender_api::WorldPoint::from_untyped(&client_point); let results = self.webrender_api.hit_test( self.webrender_document, Some(self.id.to_webrender()), client_point, flags ); rw_data.nodes_from_point_response = results.items.iter() .map(|item| UntrustedNodeAddress(item.tag.0 as *const c_void)) .collect() }, ReflowGoal::ElementInnerTextQuery(node) => { let node = unsafe { ServoLayoutNode::new(&node) }; rw_data.element_inner_text_response = process_element_inner_text_query(node, &rw_data.indexable_text); }, ReflowGoal::Full | ReflowGoal::TickAnimations => {} } } fn set_scroll_states<'a, 'b>(&mut self, new_scroll_states: Vec, possibly_locked_rw_data: &mut RwData<'a, 'b>) { let mut rw_data = possibly_locked_rw_data.lock(); let mut script_scroll_states = vec![]; let mut layout_scroll_states = HashMap::new(); for new_state in &new_scroll_states { let offset = new_state.scroll_offset; layout_scroll_states.insert(new_state.scroll_id, offset); if new_state.scroll_id.is_root() { script_scroll_states.push((UntrustedNodeAddress::from_id(0), offset)) } else if let Some(node_id) = node_id_from_scroll_id(new_state.scroll_id.0 as usize) { script_scroll_states.push((UntrustedNodeAddress::from_id(node_id), offset)) } } let _ = self.script_chan .send(ConstellationControlMsg::SetScrollState(self.id, script_scroll_states)); rw_data.scroll_offsets = layout_scroll_states } fn tick_all_animations<'a, 'b>(&mut self, possibly_locked_rw_data: &mut RwData<'a, 'b>) { let mut rw_data = possibly_locked_rw_data.lock(); self.tick_animations(&mut rw_data); } fn tick_animations(&mut self, rw_data: &mut LayoutThreadData) { if opts::get().relayout_event { println!("**** pipeline={}\tForDisplay\tSpecial\tAnimationTick", self.id); } if let Some(mut root_flow) = self.root_flow.borrow().clone() { let reflow_info = Reflow { page_clip_rect: Rect::max_rect(), }; // Unwrap here should not panic since self.root_flow is only ever set to Some(_) // in handle_reflow() where self.document_shared_lock is as well. let author_shared_lock = self.document_shared_lock.clone().unwrap(); let author_guard = author_shared_lock.read(); let ua_or_user_guard = UA_STYLESHEETS.shared_lock.read(); let guards = StylesheetGuards { author: &author_guard, ua_or_user: &ua_or_user_guard, }; let snapshots = SnapshotMap::new(); let mut layout_context = self.build_layout_context(guards, false, &snapshots); { // Perform an abbreviated style recalc that operates without access to the DOM. let animations = self.running_animations.read(); profile(time::ProfilerCategory::LayoutStyleRecalc, self.profiler_metadata(), self.time_profiler_chan.clone(), || { animation::recalc_style_for_animations::( &layout_context, FlowRef::deref_mut(&mut root_flow), &animations, ) }); } self.perform_post_style_recalc_layout_passes(&mut root_flow, &reflow_info, &ReflowGoal::TickAnimations, None, &mut *rw_data, &mut layout_context); assert!(layout_context.pending_images.is_none()); assert!(layout_context.newly_transitioning_nodes.is_none()); } } fn perform_post_style_recalc_layout_passes(&self, root_flow: &mut FlowRef, data: &Reflow, reflow_goal: &ReflowGoal, document: Option<&ServoLayoutDocument>, rw_data: &mut LayoutThreadData, context: &mut LayoutContext) { { let mut newly_transitioning_nodes = context .newly_transitioning_nodes .as_ref() .map(|nodes| nodes.lock().unwrap()); let newly_transitioning_nodes = newly_transitioning_nodes .as_mut() .map(|nodes| &mut **nodes); // Kick off animations if any were triggered, expire completed ones. animation::update_animation_state::( &self.constellation_chan, &self.script_chan, &mut *self.running_animations.write(), &mut *self.expired_animations.write(), newly_transitioning_nodes, &self.new_animations_receiver, self.id, &self.timer, ); } profile(time::ProfilerCategory::LayoutRestyleDamagePropagation, self.profiler_metadata(), self.time_profiler_chan.clone(), || { // Call `compute_layout_damage` even in non-incremental mode, because it sets flags // that are needed in both incremental and non-incremental traversals. let damage = FlowRef::deref_mut(root_flow).compute_layout_damage(); if opts::get().nonincremental_layout || damage.contains(SpecialRestyleDamage::REFLOW_ENTIRE_DOCUMENT) { FlowRef::deref_mut(root_flow).reflow_entire_document() } }); if opts::get().trace_layout { layout_debug::begin_trace(root_flow.clone()); } // Resolve generated content. profile(time::ProfilerCategory::LayoutGeneratedContent, self.profiler_metadata(), self.time_profiler_chan.clone(), || sequential::resolve_generated_content(FlowRef::deref_mut(root_flow), &context)); // Guess float placement. profile(time::ProfilerCategory::LayoutFloatPlacementSpeculation, self.profiler_metadata(), self.time_profiler_chan.clone(), || sequential::guess_float_placement(FlowRef::deref_mut(root_flow))); // Perform the primary layout passes over the flow tree to compute the locations of all // the boxes. if root_flow.base().restyle_damage.intersects(ServoRestyleDamage::REFLOW | ServoRestyleDamage::REFLOW_OUT_OF_FLOW) { profile(time::ProfilerCategory::LayoutMain, self.profiler_metadata(), self.time_profiler_chan.clone(), || { let profiler_metadata = self.profiler_metadata(); if let (true, Some(traversal)) = (self.parallel_flag, self.parallel_traversal.as_ref()) { // Parallel mode. LayoutThread::solve_constraints_parallel(traversal, FlowRef::deref_mut(root_flow), profiler_metadata, self.time_profiler_chan.clone(), &*context); } else { //Sequential mode LayoutThread::solve_constraints(FlowRef::deref_mut(root_flow), &context) } }); } profile(time::ProfilerCategory::LayoutStoreOverflow, self.profiler_metadata(), self.time_profiler_chan.clone(), || { sequential::store_overflow(context, FlowRef::deref_mut(root_flow) as &mut Flow); }); self.perform_post_main_layout_passes(data, root_flow, reflow_goal, document, rw_data, context); } fn perform_post_main_layout_passes(&self, data: &Reflow, mut root_flow: &mut FlowRef, reflow_goal: &ReflowGoal, document: Option<&ServoLayoutDocument>, rw_data: &mut LayoutThreadData, layout_context: &mut LayoutContext) { // Build the display list if necessary, and send it to the painter. self.compute_abs_pos_and_build_display_list(data, reflow_goal, document, FlowRef::deref_mut(&mut root_flow), &mut *layout_context, rw_data); if opts::get().trace_layout { layout_debug::end_trace(self.generation.get()); } if opts::get().dump_flow_tree { root_flow.print("Post layout flow tree".to_owned()); } self.generation.set(self.generation.get() + 1); } fn reflow_all_nodes(flow: &mut Flow) { debug!("reflowing all nodes!"); flow.mut_base() .restyle_damage .insert(ServoRestyleDamage::REPAINT | ServoRestyleDamage::STORE_OVERFLOW | ServoRestyleDamage::REFLOW | ServoRestyleDamage::REPOSITION); for child in flow.mut_base().child_iter_mut() { LayoutThread::reflow_all_nodes(child); } } /// Returns profiling information which is passed to the time profiler. fn profiler_metadata(&self) -> Option { Some(TimerMetadata { url: self.url.to_string(), iframe: if self.is_iframe { TimerMetadataFrameType::IFrame } else { TimerMetadataFrameType::RootWindow }, incremental: if self.first_reflow.get() { TimerMetadataReflowType::FirstReflow } else { TimerMetadataReflowType::Incremental }, }) } } impl ProfilerMetadataFactory for LayoutThread { fn new_metadata(&self) -> Option { self.profiler_metadata() } } // The default computed value for background-color is transparent (see // http://dev.w3.org/csswg/css-backgrounds/#background-color). However, we // need to propagate the background color from the root HTML/Body // element (http://dev.w3.org/csswg/css-backgrounds/#special-backgrounds) if // it is non-transparent. The phrase in the spec "If the canvas background // is not opaque, what shows through is UA-dependent." is handled by rust-layers // clearing the frame buffer to white. This ensures that setting a background // color on an iframe element, while the iframe content itself has a default // transparent background color is handled correctly. fn get_root_flow_background_color(flow: &mut Flow) -> webrender_api::ColorF { let transparent = webrender_api::ColorF { r: 0.0, g: 0.0, b: 0.0, a: 0.0 }; if !flow.is_block_like() { return transparent; } let block_flow = flow.as_mut_block(); let kid = match block_flow.base.children.iter_mut().next() { None => return transparent, Some(kid) => kid, }; if !kid.is_block_like() { return transparent; } let kid_block_flow = kid.as_block(); let color = kid_block_flow.fragment .style .resolve_color(kid_block_flow.fragment.style.get_background().background_color); webrender_api::ColorF::new( color.red_f32(), color.green_f32(), color.blue_f32(), color.alpha_f32(), ) } fn get_ua_stylesheets() -> Result { fn parse_ua_stylesheet( shared_lock: &SharedRwLock, filename: &'static str, ) -> Result { let res = read_resource_file(filename).map_err(|_| filename)?; Ok(DocumentStyleSheet(ServoArc::new(Stylesheet::from_bytes( &res, ServoUrl::parse(&format!("chrome://resources/{:?}", filename)).unwrap(), None, None, Origin::UserAgent, MediaList::empty(), shared_lock.clone(), None, &NullReporter, QuirksMode::NoQuirks, )))) } let shared_lock = SharedRwLock::new(); let mut user_or_user_agent_stylesheets = vec!(); // FIXME: presentational-hints.css should be at author origin with zero specificity. // (Does it make a difference?) for &filename in &["user-agent.css", "servo.css", "presentational-hints.css"] { user_or_user_agent_stylesheets.push(parse_ua_stylesheet(&shared_lock, filename)?); } for &(ref contents, ref url) in &opts::get().user_stylesheets { user_or_user_agent_stylesheets.push( DocumentStyleSheet(ServoArc::new(Stylesheet::from_bytes( &contents, url.clone(), None, None, Origin::User, MediaList::empty(), shared_lock.clone(), None, &RustLogReporter, QuirksMode::NoQuirks, ))) ); } let quirks_mode_stylesheet = parse_ua_stylesheet(&shared_lock, "quirks-mode.css")?; Ok(UserAgentStylesheets { shared_lock: shared_lock, user_or_user_agent_stylesheets: user_or_user_agent_stylesheets, quirks_mode_stylesheet: quirks_mode_stylesheet, }) } lazy_static! { static ref UA_STYLESHEETS: UserAgentStylesheets = { match get_ua_stylesheets() { Ok(stylesheets) => stylesheets, Err(filename) => { error!("Failed to load UA stylesheet {}!", filename); process::exit(1); } } }; } struct RegisteredPainterImpl { painter: Box, name: Atom, properties: FnvHashMap, } impl SpeculativePainter for RegisteredPainterImpl { fn speculatively_draw_a_paint_image(&self, properties: Vec<(Atom, String)>, arguments: Vec) { self.painter.speculatively_draw_a_paint_image(properties, arguments); } } impl RegisteredSpeculativePainter for RegisteredPainterImpl { fn properties(&self) -> &FnvHashMap { &self.properties } fn name(&self) -> Atom { self.name.clone() } } impl Painter for RegisteredPainterImpl { fn draw_a_paint_image(&self, size: TypedSize2D, device_pixel_ratio: TypedScale, properties: Vec<(Atom, String)>, arguments: Vec) -> Result { self.painter.draw_a_paint_image(size, device_pixel_ratio, properties, arguments) } } impl RegisteredPainter for RegisteredPainterImpl {} struct RegisteredPaintersImpl(FnvHashMap); impl RegisteredSpeculativePainters for RegisteredPaintersImpl { fn get(&self, name: &Atom) -> Option<&RegisteredSpeculativePainter> { self.0.get(&name).map(|painter| painter as &RegisteredSpeculativePainter) } } impl RegisteredPainters for RegisteredPaintersImpl { fn get(&self, name: &Atom) -> Option<&RegisteredPainter> { self.0.get(&name).map(|painter| painter as &RegisteredPainter) } }