Implement browsing context discarding.

components/constellation/constellation.rs

@@ -95,7 +95,7 @@ use profile_traits::mem;
 use profile_traits::time;
 use rand::{Rng, SeedableRng, StdRng, random};
 use script_traits::{AnimationState, AnimationTickType, CompositorEvent};
-use script_traits::{ConstellationControlMsg, ConstellationMsg as FromCompositorMsg};
+use script_traits::{ConstellationControlMsg, ConstellationMsg as FromCompositorMsg, DiscardBrowsingContext};
 use script_traits::{DocumentState, LayoutControlMsg, LoadData};
 use script_traits::{IFrameLoadInfo, IFrameLoadInfoWithData, IFrameSandboxState, TimerEventRequest};
 use script_traits::{LayoutMsg as FromLayoutMsg, ScriptMsg as FromScriptMsg, ScriptThreadFactory};
@@ -975,13 +975,11 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
                 debug!("constellation got set visibility change complete message");
                 self.handle_visibility_change_complete(pipeline_id, visible);
             }
-            FromScriptMsg::RemoveIFrame(pipeline_id, sender) => {
+            FromScriptMsg::RemoveIFrame(frame_id, sender) => {
                 debug!("constellation got remove iframe message");
-                self.handle_remove_iframe_msg(pipeline_id);
-                if let Some(sender) = sender {
-                    if let Err(e) = sender.send(()) {
-                        warn!("Error replying to remove iframe ({})", e);
-                    }
+                let removed_pipeline_ids = self.handle_remove_iframe_msg(frame_id);
+                if let Err(e) = sender.send(removed_pipeline_ids) {
+                    warn!("Error replying to remove iframe ({})", e);
                 }
             }
             FromScriptMsg::NewFavicon(url) => {
@@ -1126,7 +1124,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
             debug!("Removing pending frame {}.", pending.frame_id);
             self.close_frame(pending.frame_id, ExitPipelineMode::Normal);
             debug!("Removing pending pipeline {}.", pending.new_pipeline_id);
-            self.close_pipeline(pending.new_pipeline_id, ExitPipelineMode::Normal);
+            self.close_pipeline(pending.new_pipeline_id, DiscardBrowsingContext::Yes, ExitPipelineMode::Normal);
         }
 
         // In case there are frames which weren't attached to the frame tree, we close them.
@@ -1140,7 +1138,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         let pipeline_ids: Vec<PipelineId> = self.pipelines.keys().cloned().collect();
         for pipeline_id in pipeline_ids {
             debug!("Removing detached pipeline {}.", pipeline_id);
-            self.close_pipeline(pipeline_id, ExitPipelineMode::Normal);
+            self.close_pipeline(pipeline_id, DiscardBrowsingContext::Yes, ExitPipelineMode::Normal);
         }
     }
 
@@ -1234,7 +1232,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         let parent_info = pipeline_id.and_then(|id| self.pipelines.get(&id).and_then(|pipeline| pipeline.parent_info));
         let window_size = pipeline_id.and_then(|id| self.pipelines.get(&id).and_then(|pipeline| pipeline.size));
 
-        self.close_frame_children(top_level_frame_id, ExitPipelineMode::Force);
+        self.close_frame_children(top_level_frame_id, DiscardBrowsingContext::No, ExitPipelineMode::Force);
 
         let failure_url = ServoUrl::parse("about:failure").expect("infallible");
 
@@ -1805,20 +1803,14 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         self.focus_parent_pipeline(pipeline_id);
     }
 
-    fn handle_remove_iframe_msg(&mut self, pipeline_id: PipelineId) {
-        let frame_id = self.pipelines.get(&pipeline_id).map(|pipeline| pipeline.frame_id);
-        match frame_id {
-            Some(frame_id) => {
-                // This iframe has already loaded and been added to the frame tree.
-                self.close_frame(frame_id, ExitPipelineMode::Normal);
-            }
-            None => {
-                // This iframe is currently loading / painting for the first time.
-                // In this case, it doesn't exist in the frame tree, but the pipeline
-                // still needs to be shut down.
-                self.close_pipeline(pipeline_id, ExitPipelineMode::Normal);
-            }
-        }
+    fn handle_remove_iframe_msg(&mut self, frame_id: FrameId) -> Vec<PipelineId> {
+        let result = self.full_frame_tree_iter(frame_id)
+            .flat_map(|frame| frame.next.iter().chain(frame.prev.iter())
+                      .filter_map(|entry| entry.pipeline_id)
+                      .chain(once(frame.pipeline_id)))
+            .collect();
+        self.close_frame(frame_id, ExitPipelineMode::Normal);
+        result
     }
 
     fn handle_set_visible_msg(&mut self, pipeline_id: PipelineId, visible: bool) {
@@ -2118,7 +2110,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         };
 
         if let Some(evicted_id) = evicted_id {
-            self.close_pipeline(evicted_id, ExitPipelineMode::Normal);
+            self.close_pipeline(evicted_id, DiscardBrowsingContext::No, ExitPipelineMode::Normal);
         }
 
         if new_frame {
@@ -2344,7 +2336,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
             };
             for entry in evicted {
                 if let Some(pipeline_id) = entry.pipeline_id {
-                    self.close_pipeline(pipeline_id, ExitPipelineMode::Normal);
+                    self.close_pipeline(pipeline_id, DiscardBrowsingContext::No, ExitPipelineMode::Normal);
                 }
             }
         }
@@ -2357,7 +2349,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
             .and_then(|frame| self.pipelines.get(&frame.pipeline_id))
             .and_then(|pipeline| pipeline.parent_info);
 
-        self.close_frame_children(frame_id, exit_mode);
+        self.close_frame_children(frame_id, DiscardBrowsingContext::Yes, exit_mode);
 
         self.event_loops.remove(&frame_id);
         if self.frames.remove(&frame_id).is_none() {
@@ -2375,7 +2367,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
     }
 
     // Close the children of a frame
-    fn close_frame_children(&mut self, frame_id: FrameId, exit_mode: ExitPipelineMode) {
+    fn close_frame_children(&mut self, frame_id: FrameId, dbc: DiscardBrowsingContext, exit_mode: ExitPipelineMode) {
         debug!("Closing frame children {}.", frame_id);
         // Store information about the pipelines to be closed. Then close the
         // pipelines, before removing ourself from the frames hash map. This
@@ -2393,18 +2385,18 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         }
 
         for pipeline_id in pipelines_to_close {
-            self.close_pipeline(pipeline_id, exit_mode);
+            self.close_pipeline(pipeline_id, dbc, exit_mode);
         }
 
         debug!("Closed frame children {}.", frame_id);
     }
 
     // Close all pipelines at and beneath a given frame
-    fn close_pipeline(&mut self, pipeline_id: PipelineId, exit_mode: ExitPipelineMode) {
+    fn close_pipeline(&mut self, pipeline_id: PipelineId, dbc: DiscardBrowsingContext, exit_mode: ExitPipelineMode) {
         debug!("Closing pipeline {:?}.", pipeline_id);
         // Store information about the frames to be closed. Then close the
         // frames, before removing ourself from the pipelines hash map. This
-        // ordering is vital - so that if close_frames() ends up closing
+        // ordering is vital - so that if close_frame() ends up closing
         // any child pipelines, they can be removed from the parent pipeline correctly.
         let frames_to_close = {
             let mut frames_to_close = vec!();
@@ -2438,8 +2430,8 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
 
         // Inform script, compositor that this pipeline has exited.
         match exit_mode {
-            ExitPipelineMode::Normal => pipeline.exit(),
-            ExitPipelineMode::Force => pipeline.force_exit(),
+            ExitPipelineMode::Normal => pipeline.exit(dbc),
+            ExitPipelineMode::Force => pipeline.force_exit(dbc),
         }
         debug!("Closed pipeline {:?}.", pipeline_id);
     }
@@ -2463,7 +2455,7 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
                         // Note that we deliberately do not do any of the tidying up
                         // associated with closing a pipeline. The constellation should cope!
                         warn!("Randomly closing pipeline {}.", pipeline_id);
-                        pipeline.force_exit();
+                        pipeline.force_exit(DiscardBrowsingContext::No);
                     }
                 }
             }

components/constellation/pipeline.rs

@@ -20,7 +20,7 @@ use net_traits::{IpcSend, ResourceThreads};
 use net_traits::image_cache_thread::ImageCacheThread;
 use profile_traits::mem as profile_mem;
 use profile_traits::time;
-use script_traits::{ConstellationControlMsg, InitialScriptState};
+use script_traits::{ConstellationControlMsg, DiscardBrowsingContext, InitialScriptState};
 use script_traits::{LayoutControlMsg, LayoutMsg, LoadData, MozBrowserEvent};
 use script_traits::{NewLayoutInfo, SWManagerMsg, SWManagerSenders, ScriptMsg};
 use script_traits::{ScriptThreadFactory, TimerEventRequest, WindowSizeData};
@@ -328,7 +328,7 @@ impl Pipeline {
 
     /// A normal exit of the pipeline, which waits for the compositor,
     /// and delegates layout shutdown to the script thread.
-    pub fn exit(&self) {
+    pub fn exit(&self, discard_bc: DiscardBrowsingContext) {
         debug!("pipeline {:?} exiting", self.id);
 
         // The compositor wants to know when pipelines shut down too.
@@ -345,15 +345,17 @@ impl Pipeline {
 
         // Script thread handles shutting down layout, and layout handles shutting down the painter.
         // For now, if the script thread has failed, we give up on clean shutdown.
-        if let Err(e) = self.event_loop.send(ConstellationControlMsg::ExitPipeline(self.id)) {
+        let msg = ConstellationControlMsg::ExitPipeline(self.id, discard_bc);
+        if let Err(e) = self.event_loop.send(msg) {
             warn!("Sending script exit message failed ({}).", e);
         }
     }
 
     /// A forced exit of the shutdown, which does not wait for the compositor,
     /// or for the script thread to shut down layout.
-    pub fn force_exit(&self) {
-        if let Err(e) = self.event_loop.send(ConstellationControlMsg::ExitPipeline(self.id)) {
+    pub fn force_exit(&self, discard_bc: DiscardBrowsingContext) {
+        let msg = ConstellationControlMsg::ExitPipeline(self.id, discard_bc);
+        if let Err(e) = self.event_loop.send(msg) {
             warn!("Sending script exit message failed ({}).", e);
         }
         if let Err(e) = self.layout_chan.send(LayoutControlMsg::ExitNow) {

components/script/dom/browsingcontext.rs

@@ -3,16 +3,13 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::conversions::{ToJSValConvertible, root_from_handleobject};
-use dom::bindings::inheritance::Castable;
-use dom::bindings::js::{JS, MutNullableJS, Root, RootedReference};
+use dom::bindings::js::{JS, Root, RootedReference};
 use dom::bindings::proxyhandler::{fill_property_descriptor, get_property_descriptor};
 use dom::bindings::reflector::{DomObject, MutDomObject, Reflector};
 use dom::bindings::trace::JSTraceable;
 use dom::bindings::utils::WindowProxyHandler;
 use dom::bindings::utils::get_array_index_from_id;
-use dom::document::Document;
 use dom::element::Element;
-use dom::globalscope::GlobalScope;
 use dom::window::Window;
 use js::JSCLASS_IS_GLOBAL;
 use js::glue::{CreateWrapperProxyHandler, ProxyTraps, NewWindowProxy};
@@ -26,7 +23,6 @@ use js::jsapi::{MutableHandle, MutableHandleObject, MutableHandleValue};
 use js::jsapi::{ObjectOpResult, PropertyDescriptor};
 use js::jsval::{UndefinedValue, PrivateValue};
 use js::rust::get_object_class;
-use msg::constellation_msg::PipelineId;
 use std::cell::Cell;
 
 #[dom_struct]
@@ -40,10 +36,8 @@ pub struct BrowsingContext {
     /// Indicates if reflow is required when reloading.
     needs_reflow: Cell<bool>,
 
-    /// The current active document.
-    /// Note that the session history is stored in the constellation,
-    /// in the script thread we just track the current active document.
-    active_document: MutNullableJS<Document>,
+    /// Has this browsing context been discarded?
+    discarded: Cell<bool>,
 
     /// The containing iframe element, if this is a same-origin iframe
     frame_element: Option<JS<Element>>,
@@ -54,7 +48,7 @@ impl BrowsingContext {
         BrowsingContext {
             reflector: Reflector::new(),
             needs_reflow: Cell::new(true),
-            active_document: Default::default(),
+            discarded:  Cell::new(false),
             frame_element: frame_element.map(JS::from_ref),
         }
     }
@@ -84,20 +78,12 @@ impl BrowsingContext {
         }
     }
 
-    pub fn set_active_document(&self, document: &Document) {
-        self.active_document.set(Some(document))
+    pub fn discard(&self) {
+        self.discarded.set(true);
     }
 
-    pub fn active_document(&self) -> Root<Document> {
-        self.active_document.get().expect("No active document.")
-    }
-
-    pub fn maybe_active_document(&self) -> Option<Root<Document>> {
-        self.active_document.get()
-    }
-
-    pub fn active_window(&self) -> Root<Window> {
-        Root::from_ref(self.active_document().window())
+    pub fn is_discarded(&self) -> bool {
+        self.discarded.get()
     }
 
     pub fn frame_element(&self) -> Option<&Element> {
@@ -115,15 +101,6 @@ impl BrowsingContext {
         self.needs_reflow.set(status);
         old
     }
-
-    pub fn active_pipeline_id(&self) -> Option<PipelineId> {
-        self.active_document.get()
-            .map(|doc| doc.window().upcast::<GlobalScope>().pipeline_id())
-    }
-
-    pub fn unset_active_document(&self) {
-        self.active_document.set(None)
-    }
 }
 
 #[allow(unsafe_code)]

components/script/dom/document.rs

@@ -190,6 +190,7 @@ pub struct Document {
     last_modified: Option<String>,
     encoding: Cell<EncodingRef>,
     is_html_document: bool,
+    is_fully_active: Cell<bool>,
     url: DOMRefCell<ServoUrl>,
     quirks_mode: Cell<QuirksMode>,
     /// Caches for the getElement methods
@@ -385,20 +386,17 @@ impl Document {
         self.trigger_mozbrowser_event(MozBrowserEvent::SecurityChange(https_state));
     }
 
-    // https://html.spec.whatwg.org/multipage/#active-document
-    pub fn is_active(&self) -> bool {
-        self.browsing_context().map_or(false, |context| {
-            self == &*context.active_document()
-        })
-    }
-
     // https://html.spec.whatwg.org/multipage/#fully-active
     pub fn is_fully_active(&self) -> bool {
-        if !self.is_active() {
-            return false;
-        }
-        // FIXME: It should also check whether the browser context is top-level or not
-        true
+        self.is_fully_active.get()
+    }
+
+    pub fn fully_activate(&self) {
+        self.is_fully_active.set(true)
+    }
+
+    pub fn fully_deactivate(&self) {
+        self.is_fully_active.set(false)
     }
 
     pub fn origin(&self) -> &Origin {
@@ -1693,11 +1691,16 @@ impl Document {
         self.current_parser.get()
     }
 
-    /// Find an iframe element in the document.
-    pub fn find_iframe(&self, frame_id: FrameId) -> Option<Root<HTMLIFrameElement>> {
+    /// Iterate over all iframes in the document.
+    pub fn iter_iframes(&self) -> impl Iterator<Item=Root<HTMLIFrameElement>> {
         self.upcast::<Node>()
             .traverse_preorder()
             .filter_map(Root::downcast::<HTMLIFrameElement>)
+    }
+
+    /// Find an iframe element in the document.
+    pub fn find_iframe(&self, frame_id: FrameId) -> Option<Root<HTMLIFrameElement>> {
+        self.iter_iframes()
             .find(|node| node.frame_id() == frame_id)
     }
 
@@ -1864,6 +1867,7 @@ impl Document {
             // https://dom.spec.whatwg.org/#concept-document-encoding
             encoding: Cell::new(UTF_8),
             is_html_document: is_html_document == IsHTMLDocument::HTMLDocument,
+            is_fully_active: Cell::new(false),
             id_map: DOMRefCell::new(HashMap::new()),
             tag_map: DOMRefCell::new(HashMap::new()),
             tagns_map: DOMRefCell::new(HashMap::new()),
@@ -2261,19 +2265,12 @@ impl DocumentMethods for Document {
 
     // https://html.spec.whatwg.org/multipage/#dom-document-hasfocus
     fn HasFocus(&self) -> bool {
-        match self.browsing_context() {
-            Some(browsing_context) => {
-                // Step 2.
-                let candidate = browsing_context.active_document();
-                // Step 3.
-                if &*candidate == self {
-                    true
-                } else {
-                    false //TODO  Step 4.
-                }
-            }
-            None => false,
+        // Step 1-2.
+        if self.window().parent_info().is_none() && self.is_fully_active() {
+            return true;
         }
+        // TODO Step 3.
+        false
     }
 
     // https://html.spec.whatwg.org/multipage/#relaxing-the-same-origin-restriction
@@ -3190,8 +3187,8 @@ impl DocumentMethods for Document {
 
         // Step 2.
         // TODO: handle throw-on-dynamic-markup-insertion counter.
-
-        if !self.is_active() {
+        // FIXME: this should check for being active rather than fully active
+        if !self.is_fully_active() {
             // Step 3.
             return Ok(());
         }