First part of refactoring constellation to support iframe navigation.

The history is now recorded per frame, but needs to be exposed in a followup PR.

Also fixes a race condition that occurs loading iframes under heavy CPU load.

This ensures that iframes never do a reflow / layout until they have a valid
window size set from their parent frame.

components/compositing/compositor.rs

@@ -291,18 +291,6 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                 self.get_title_for_main_frame();
             }
 
-            (Msg::ChangeLayerPipelineAndRemoveChildren(old_pipeline, new_pipeline, response_channel),
-             ShutdownState::NotShuttingDown) => {
-                self.handle_change_layer_pipeline_and_remove_children(old_pipeline, new_pipeline);
-                response_channel.send(()).unwrap();
-            }
-
-            (Msg::CreateRootLayerForPipeline(parent_pipeline, pipeline, rect, response_channel),
-             ShutdownState::NotShuttingDown) => {
-                self.handle_create_root_layer_for_pipeline(parent_pipeline, pipeline, rect);
-                response_channel.send(()).unwrap();
-            }
-
             (Msg::CreateOrUpdateBaseLayer(layer_properties), ShutdownState::NotShuttingDown) => {
                 self.create_or_update_base_layer(layer_properties);
             }
@@ -554,62 +542,11 @@ impl<Window: WindowMethods> IOCompositor<Window> {
         let root_layer = self.create_root_layer_for_pipeline_and_rect(&frame_tree.pipeline,
                                                                       frame_rect);
         for kid in frame_tree.children.iter() {
-            root_layer.add_child(self.create_frame_tree_root_layers(&kid.frame_tree, kid.rect));
+            root_layer.add_child(self.create_frame_tree_root_layers(kid, kid.rect));
         }
         return root_layer;
     }
 
-    fn handle_change_layer_pipeline_and_remove_children(&mut self,
-                                                        old_pipeline: CompositionPipeline,
-                                                        new_pipeline: CompositionPipeline) {
-        let root_layer = match self.find_pipeline_root_layer(old_pipeline.id) {
-            Some(root_layer) => root_layer,
-            None => {
-                debug!("Ignoring ChangeLayerPipelineAndRemoveChildren message \
-                        for pipeline ({:?}) shutting down.",
-                       old_pipeline.id);
-                return;
-            }
-        };
-
-        root_layer.clear_all_tiles(self);
-        root_layer.children().clear();
-
-        debug_assert!(root_layer.extra_data.borrow().pipeline_id == old_pipeline.id);
-        root_layer.extra_data.borrow_mut().pipeline_id = new_pipeline.id;
-
-        let new_pipeline_id = new_pipeline.id;
-        self.get_or_create_pipeline_details(new_pipeline_id).pipeline = Some(new_pipeline);
-    }
-
-    fn handle_create_root_layer_for_pipeline(&mut self,
-                                             parent_pipeline: CompositionPipeline,
-                                             new_pipeline: CompositionPipeline,
-                                             frame_rect: Option<TypedRect<PagePx, f32>>) {
-        let root_layer = self.create_root_layer_for_pipeline_and_rect(&new_pipeline, frame_rect);
-        match frame_rect {
-            Some(ref frame_rect) => {
-                *root_layer.masks_to_bounds.borrow_mut() = true;
-
-                let frame_rect = frame_rect.to_untyped();
-                *root_layer.bounds.borrow_mut() = Rect::from_untyped(&frame_rect);
-            }
-            None => {}
-        }
-
-        let pipeline_id = parent_pipeline.id;
-        let parent_layer = match self.find_pipeline_root_layer(pipeline_id) {
-            Some(root_layer) => root_layer,
-            None => {
-                debug!("Ignoring FrameTreeUpdate message for pipeline ({:?}) \
-                        shutting down.",
-                       pipeline_id);
-                return;
-            }
-        };
-        parent_layer.add_child(root_layer);
-    }
-
     fn find_pipeline_root_layer(&self, pipeline_id: PipelineId) -> Option<Rc<Layer<CompositorData>>> {
         if !self.pipeline_details.contains_key(&pipeline_id) {
             panic!("Tried to create or update layer for unknown pipeline")

components/compositing/compositor_task.rs

@@ -13,18 +13,16 @@ use windowing::{WindowEvent, WindowMethods};
 
 use azure::azure_hl::{SourceSurfaceMethods, Color};
 use geom::point::Point2D;
-use geom::rect::{Rect, TypedRect};
+use geom::rect::Rect;
 use geom::size::Size2D;
 use layers::platform::surface::{NativeCompositingGraphicsContext, NativeGraphicsMetadata};
 use layers::layers::LayerBufferSet;
-use pipeline::CompositionPipeline;
 use msg::compositor_msg::{Epoch, LayerId, LayerMetadata, ReadyState};
 use msg::compositor_msg::{PaintListener, PaintState, ScriptListener, ScrollPolicy};
 use msg::constellation_msg::{ConstellationChan, PipelineId};
 use msg::constellation_msg::{Key, KeyState, KeyModifiers};
 use url::Url;
 use util::cursor::Cursor;
-use util::geometry::PagePx;
 use util::memory::MemoryProfilerChan;
 use util::time::TimeProfilerChan;
 use std::sync::mpsc::{channel, Sender, Receiver};
@@ -207,10 +205,6 @@ pub enum Msg {
     PaintMsgDiscarded,
     /// Replaces the current frame tree, typically called during main frame navigation.
     SetFrameTree(SendableFrameTree, Sender<()>, ConstellationChan),
-    /// Requests the compositor to create a root layer for a new frame.
-    CreateRootLayerForPipeline(CompositionPipeline, CompositionPipeline, Option<TypedRect<PagePx, f32>>, Sender<()>),
-    /// Requests the compositor to change a root layer's pipeline and remove all child layers.
-    ChangeLayerPipelineAndRemoveChildren(CompositionPipeline, CompositionPipeline, Sender<()>),
     /// The load of a page has completed.
     LoadComplete,
     /// Indicates that the scrolling timeout with the given starting timestamp has happened and a
@@ -241,8 +235,6 @@ impl Debug for Msg {
             Msg::ChangePageUrl(..) => write!(f, "ChangePageUrl"),
             Msg::PaintMsgDiscarded(..) => write!(f, "PaintMsgDiscarded"),
             Msg::SetFrameTree(..) => write!(f, "SetFrameTree"),
-            Msg::CreateRootLayerForPipeline(..) => write!(f, "CreateRootLayerForPipeline"),
-            Msg::ChangeLayerPipelineAndRemoveChildren(..) => write!(f, "ChangeLayerPipelineAndRemoveChildren"),
             Msg::LoadComplete => write!(f, "LoadComplete"),
             Msg::ScrollTimeout(..) => write!(f, "ScrollTimeout"),
             Msg::KeyEvent(..) => write!(f, "KeyEvent"),

components/compositing/headless.rs

@@ -90,14 +90,6 @@ impl CompositorEventListener for NullCompositor {
                 response_chan.send(()).unwrap();
             }
 
-            Msg::ChangeLayerPipelineAndRemoveChildren(_, _, response_channel) => {
-                response_channel.send(()).unwrap();
-            }
-
-            Msg::CreateRootLayerForPipeline(_, _, _, response_channel) => {
-                response_channel.send(()).unwrap();
-            }
-
             // Explicitly list ignored messages so that when we add a new one,
             // we'll notice and think about whether it needs a response, like
             // SetFrameTree.

components/compositing/pipeline.rs

@@ -8,23 +8,24 @@ use script_traits::{ScriptControlChan, ScriptTaskFactory};
 use script_traits::{NewLayoutInfo, ConstellationControlMsg};
 
 use devtools_traits::DevtoolsControlChan;
+use geom::rect::{TypedRect};
 use gfx::paint_task::Msg as PaintMsg;
 use gfx::paint_task::{PaintChan, PaintTask};
 use gfx::font_cache_task::FontCacheTask;
-use msg::constellation_msg::{ConstellationChan, Failure, PipelineId, SubpageId};
+use msg::constellation_msg::{ConstellationChan, Failure, FrameId, PipelineId, SubpageId};
 use msg::constellation_msg::{LoadData, WindowSizeData, PipelineExitType};
 use net::image_cache_task::ImageCacheTask;
 use net::resource_task::ResourceTask;
 use net::storage_task::StorageTask;
 use url::Url;
+use util::geometry::{PagePx};
 use util::time::TimeProfilerChan;
-use std::rc::Rc;
 use std::sync::mpsc::{Receiver, channel};
 
 /// A uniquely-identifiable pipeline of script task, layout task, and paint task.
 pub struct Pipeline {
     pub id: PipelineId,
-    pub parent: Option<(PipelineId, SubpageId)>,
+    pub parent_info: Option<(PipelineId, SubpageId)>,
     pub script_chan: ScriptControlChan,
     pub layout_chan: LayoutControlChan,
     pub paint_chan: PaintChan,
@@ -34,6 +35,8 @@ pub struct Pipeline {
     pub url: Url,
     /// The title of the most recently-loaded page.
     pub title: Option<String>,
+    pub rect: Option<TypedRect<PagePx, f32>>,
+    pub children: Vec<FrameId>,
 }
 
 /// The subset of the pipeline that is needed for layer composition.
@@ -49,7 +52,7 @@ impl Pipeline {
     /// Returns the channels wrapped in a struct.
     /// If script_pipeline is not None, then subpage_id must also be not None.
     pub fn create<LTF,STF>(id: PipelineId,
-                           parent: Option<(PipelineId, SubpageId)>,
+                           parent_info: Option<(PipelineId, SubpageId)>,
                            constellation_chan: ConstellationChan,
                            compositor_proxy: Box<CompositorProxy+'static+Send>,
                            devtools_chan: Option<DevtoolsControlChan>,
@@ -58,8 +61,8 @@ impl Pipeline {
                            resource_task: ResourceTask,
                            storage_task: StorageTask,
                            time_profiler_chan: TimeProfilerChan,
-                           window_size: WindowSizeData,
-                           script_pipeline: Option<Rc<Pipeline>>,
+                           window_size: Option<WindowSizeData>,
+                           script_chan: Option<ScriptControlChan>,
                            load_data: LoadData)
                            -> Pipeline
                            where LTF: LayoutTaskFactory, STF:ScriptTaskFactory {
@@ -71,10 +74,10 @@ impl Pipeline {
 
         let failure = Failure {
             pipeline_id: id,
-            parent: parent,
+            parent_info: parent_info,
         };
 
-        let script_chan = match script_pipeline {
+        let script_chan = match script_chan {
             None => {
                 let (script_chan, script_port) = channel();
                 ScriptTaskFactory::create(None::<&mut STF>,
@@ -93,18 +96,19 @@ impl Pipeline {
                                           load_data.clone());
                 ScriptControlChan(script_chan)
             }
-            Some(spipe) => {
+            Some(script_chan) => {
+                let (containing_pipeline_id, subpage_id) = parent_info.expect("script_pipeline != None but subpage_id == None");
                 let new_layout_info = NewLayoutInfo {
-                    old_pipeline_id: spipe.id.clone(),
+                    containing_pipeline_id: containing_pipeline_id,
                     new_pipeline_id: id,
-                    subpage_id: parent.expect("script_pipeline != None but subpage_id == None").1,
+                    subpage_id: subpage_id,
                     layout_chan: ScriptTaskFactory::clone_layout_channel(None::<&mut STF>, &layout_pair),
                     load_data: load_data.clone(),
                 };
 
-                let ScriptControlChan(ref chan) = spipe.script_chan;
+                let ScriptControlChan(ref chan) = script_chan;
                 chan.send(ConstellationControlMsg::AttachLayout(new_layout_info)).unwrap();
-                spipe.script_chan.clone()
+                script_chan.clone()
             }
         };
 
@@ -132,7 +136,7 @@ impl Pipeline {
                                   layout_shutdown_chan);
 
         Pipeline::new(id,
-                      parent,
+                      parent_info,
                       script_chan,
                       LayoutControlChan(pipeline_chan),
                       paint_chan,
@@ -142,7 +146,7 @@ impl Pipeline {
     }
 
     pub fn new(id: PipelineId,
-               parent: Option<(PipelineId, SubpageId)>,
+               parent_info: Option<(PipelineId, SubpageId)>,
                script_chan: ScriptControlChan,
                layout_chan: LayoutControlChan,
                paint_chan: PaintChan,
@@ -152,7 +156,7 @@ impl Pipeline {
                -> Pipeline {
         Pipeline {
             id: id,
-            parent: parent,
+            parent_info: parent_info,
             script_chan: script_chan,
             layout_chan: layout_chan,
             paint_chan: paint_chan,
@@ -160,14 +164,11 @@ impl Pipeline {
             paint_shutdown_port: paint_shutdown_port,
             url: url,
             title: None,
+            children: vec!(),
+            rect: None,
         }
     }
 
-    pub fn activate(&self) {
-        let ScriptControlChan(ref chan) = self.script_chan;
-        chan.send(ConstellationControlMsg::Activate(self.id)).unwrap();
-    }
-
     pub fn grant_paint_permission(&self) {
         let _ = self.paint_chan.send(PaintMsg::PaintPermissionGranted);
     }
@@ -221,7 +222,7 @@ impl Pipeline {
         }
     }
 
-    pub fn subpage_id(&self) -> Option<SubpageId> {
-      self.parent.map(|parent| parent.1)
+    pub fn add_child(&mut self, frame_id: FrameId) {
+        self.children.push(frame_id);
     }
 }