Pipeline create is now wrapped in a task that supervises the tasks

created by script, rendering, and layout. When any of those fail,
the pipeline is removed from the FrameTree and a new one is created
with a failure HTML file.

Additionally, the top-level Makefile is changed to store debug info.

Makefile.in

@@ -32,7 +32,7 @@ MKFILE_DEPS := config.stamp $(call rwildcard,$(S)mk/,*)
 # Enable debug!() etc even without configure --enable-debug
 # The evaluation of these prints & their arguments is controlled
 # at runtime by the environment variable RUST_LOG.
-CFG_RUSTC_FLAGS += --cfg debug
+CFG_RUSTC_FLAGS += --cfg debug -Z debug-info
 
 ifdef CFG_DISABLE_OPTIMIZE
   $(info cfg: disabling rustc optimization (CFG_DISABLE_OPTIMIZE))
@@ -43,7 +43,7 @@ endif
 
 ifdef CFG_ENABLE_DEBUG
   $(info cfg: enabling more debugging (CFG_ENABLE_DEBUG))
-  CFG_RUSTC_FLAGS +=
+  CFG_RUSTC_FLAGS += 
   CFG_GCCISH_CFLAGS += -DRUST_DEBUG
 else
   CFG_GCCISH_CFLAGS += -DRUST_NDEBUG

src/components/main/compositing/compositor_layer.rs

@@ -486,7 +486,14 @@ impl CompositorLayer {
         } else { 
                 // ID does not match ours, so recurse on descendents (including hidden children).
                 self.children.mut_iter().map(|x| &mut x.child)
-                    .any(|x| x.add_buffers(pipeline_id, cell.take(), epoch))
+                    .any(|x| { let buffers = cell.take();
+                               let result = x.add_buffers(pipeline_id, buffers.clone(), epoch);
+                               if result {
+                                   result
+                               } else {
+                                   cell.put_back(buffers);
+                                   result
+                               }})
         }
     }
 

src/components/main/constellation.rs

@@ -13,8 +13,8 @@ use geom::size::Size2D;
 use geom::rect::Rect;
 use gfx::opts::Opts;
 use pipeline::Pipeline;
-use servo_msg::constellation_msg::{ConstellationChan, ExitMsg, FrameRectMsg, IFrameSandboxState};
-use servo_msg::constellation_msg::{InitLoadUrlMsg, LoadIframeUrlMsg, LoadUrlMsg};
+use servo_msg::constellation_msg::{ConstellationChan, ExitMsg, FailureMsg, FrameRectMsg};
+use servo_msg::constellation_msg::{IFrameSandboxState, InitLoadUrlMsg, LoadIframeUrlMsg, LoadUrlMsg};
 use servo_msg::constellation_msg::{Msg, NavigateMsg, NavigationType, IFrameUnsandboxed};
 use servo_msg::constellation_msg::{PipelineId, RendererReadyMsg, ResizedWindowMsg, SubpageId};
 use servo_msg::constellation_msg;
@@ -23,6 +23,7 @@ use servo_net::image_cache_task::{ImageCacheTask, ImageCacheTaskClient};
 use servo_net::resource_task::ResourceTask;
 use servo_net::resource_task;
 use servo_util::time::ProfilerChan;
+use servo_util::url::make_url;
 use std::hashmap::{HashMap, HashSet};
 use std::util::replace;
 use extra::url::Url;
@@ -319,6 +320,9 @@ impl Constellation {
                 self.handle_exit(sender);
                 return false;
             }
+            FailureMsg(pipeline_id, subpage_id) => {
+                self.handle_failure_msg(pipeline_id, subpage_id);
+            }
             // This should only be called once per constellation, and only by the browser
             InitLoadUrlMsg(url) => {
                 self.handle_init_load(url);
@@ -363,6 +367,39 @@ impl Constellation {
         sender.send(());
     }
 
+    fn handle_failure_msg(&mut self, pipeline_id: PipelineId, subpage_id: Option<SubpageId>) {
+        let new_id = self.get_next_pipeline_id();
+        let pipeline = @mut Pipeline::create(new_id,
+                                             subpage_id,
+                                             self.chan.clone(),
+                                             self.compositor_chan.clone(),
+                                             self.image_cache_task.clone(),
+                                             self.resource_task.clone(),
+                                             self.profiler_chan.clone(),
+                                             self.opts.clone(),
+                                             {
+                                                let size = self.compositor_chan.get_size();
+                                                from_value(Size2D(size.width as uint, size.height as uint))
+                                             });
+        // FIXME(lbergstrom): this should be in/relative-to the servo binary
+        let failure = ~"../src/test/html/failure.html";
+        let url = make_url(failure, None);
+        pipeline.load(url);
+
+        let frame_trees: ~[@mut FrameTree] = {
+            let matching_navi_frames = self.navigation_context.find_all(pipeline_id);
+            let matching_pending_frames = do self.pending_frames.iter().filter_map |frame_change| {
+                frame_change.after.find_mut(pipeline_id)
+            };
+            matching_navi_frames.move_iter().chain(matching_pending_frames).collect()
+        };
+        for frame_tree in frame_trees.iter() {
+            frame_tree.pipeline = pipeline;
+        };
+
+        self.pipelines.insert(pipeline_id, pipeline);
+    }
+
     fn handle_init_load(&mut self, url: Url) {
         let pipeline = @mut Pipeline::create(self.get_next_pipeline_id(),
                                              None,

src/components/main/pipeline.rs

@@ -11,7 +11,7 @@ use gfx::opts::Opts;
 use layout::layout_task::LayoutTask;
 use script::layout_interface::LayoutChan;
 use script::script_task::{ExecuteMsg, LoadMsg};
-use servo_msg::constellation_msg::{ConstellationChan, PipelineId, SubpageId};
+use servo_msg::constellation_msg::{ConstellationChan, FailureMsg, PipelineId, SubpageId};
 use script::dom::node::AbstractNode;
 use script::script_task::{AttachLayoutMsg, NewLayoutInfo, ScriptTask, ScriptChan};
 use script::script_task;
@@ -20,9 +20,11 @@ use servo_net::resource_task::ResourceTask;
 use servo_util::time::ProfilerChan;
 use geom::size::Size2D;
 use extra::future::Future;
+use std::cell::Cell;
 use std::comm;
+use std::task;
 
-/// A uniquely-identifiable pipeline of stript task, layout task, and render task. 
+/// A uniquely-identifiable pipeline of script task, layout task, and render task. 
 #[deriving(Clone)]
 pub struct Pipeline {
     id: PipelineId,
@@ -94,37 +96,81 @@ impl Pipeline {
         let (script_port, script_chan) = special_stream!(ScriptChan);
         let (layout_port, layout_chan) = special_stream!(LayoutChan);
         let (render_port, render_chan) = special_stream!(RenderChan);
+        let pipeline = Pipeline::new(id,
+                                     subpage_id,
+                                     script_chan.clone(),
+                                     layout_chan.clone(),
+                                     render_chan.clone());
+        let (port, chan) = stream::<task::TaskResult>();
+        
+        let script_port = Cell::new(script_port);
+        let resource_task = Cell::new(resource_task);
+        let size = Cell::new(size);
+        let render_port = Cell::new(render_port);
+        let layout_port = Cell::new(layout_port);
+        let constellation_chan_handler = Cell::new(constellation_chan.clone());
+        let constellation_chan = Cell::new(constellation_chan);
+        let image_cache_task = Cell::new(image_cache_task);
+        let profiler_chan = Cell::new(profiler_chan);
 
-        ScriptTask::create(id,
-                           compositor_chan.clone(),
-                           layout_chan.clone(),
-                           script_port,
-                           script_chan.clone(),
-                           constellation_chan.clone(),
-                           resource_task,
-                           image_cache_task.clone(),
-                           size);
+        do Pipeline::spawn(chan) {
+            let script_port = script_port.take();
+            let resource_task = resource_task.take();
+            let size = size.take();
+            let render_port = render_port.take();
+            let layout_port = layout_port.take();
+            let constellation_chan = constellation_chan.take();
+            let image_cache_task = image_cache_task.take();
+            let profiler_chan = profiler_chan.take();
 
+            ScriptTask::create(id,
+                               compositor_chan.clone(),
+                               layout_chan.clone(),
+                               script_port,
+                               script_chan.clone(),
+                               constellation_chan.clone(),
+                               resource_task,
+                               image_cache_task.clone(),
+                               size);
 
-        RenderTask::create(id,
-                           render_port,
-                           compositor_chan.clone(),
-                           opts.clone(),
-                           profiler_chan.clone());
+            RenderTask::create(id,
+                               render_port,
+                               compositor_chan.clone(),
+                               opts.clone(),
+                               profiler_chan.clone());
 
-        LayoutTask::create(id,
-                           layout_port,
-                           constellation_chan,
-                           script_chan.clone(),
-                           render_chan.clone(),
-                           image_cache_task,
-                           opts.clone(),
-                           profiler_chan);
-        Pipeline::new(id,
-                      subpage_id,
-                      script_chan,
-                      layout_chan,
-                      render_chan)
+            LayoutTask::create(id,
+                               layout_port,
+                               constellation_chan,
+                               script_chan.clone(),
+                               render_chan.clone(),
+                               image_cache_task,
+                               opts.clone(),
+                               profiler_chan);
+        };
+
+        do spawn {
+            match port.recv() {
+                task::Success => (),
+                task::Failure => {
+                    let constellation_chan = constellation_chan_handler.take();
+                    constellation_chan.send(FailureMsg(id, subpage_id));
+                }
+            }
+        };
+
+        pipeline
+    }
+
+    /// This function wraps the task creation within a supervised task
+    /// so that failure will only tear down those tasks instead of ours.
+    pub fn spawn(chan:Chan<task::TaskResult>, f:~fn()) {
+        let mut task = task::task();
+        task.opts.notify_chan = Some(chan);
+        task.supervised();
+        do task.spawn {
+            f();
+        };
     }
 
     pub fn new(id: PipelineId,

src/components/msg/constellation_msg.rs

@@ -35,6 +35,7 @@ pub enum IFrameSandboxState {
 
 pub enum Msg {
     ExitMsg(Chan<()>),
+    FailureMsg(PipelineId, Option<SubpageId>),
     InitLoadUrlMsg(Url),
     FrameRectMsg(PipelineId, SubpageId, Rect<f32>),
     LoadUrlMsg(PipelineId, Url, Future<Size2D<uint>>),

src/test/html/failure.html

@@ -0,0 +1,8 @@
+<html>
+<head>
+  <title>about:failure</title>
+</head>
+<body>
+  <img src="andreas.jpeg"/>
+</body>
+</html>

src/test/html/summit-crash.html

@@ -0,0 +1,12 @@
+<html>
+  <head>
+    <title>Summit demo crash page</title>
+  </head>
+  <body>
+    <audio>
+      <source src="horse.ogg" type="audio/ogg">
+      <source src="horse.mp3" type="audio/mpeg">
+    </audio>
+    <pre>pre</pre>
+  </body>
+</html>

src/test/html/summit-link.html

@@ -0,0 +1,9 @@
+<html>
+<head>
+  <title>Summit page linking to the crash page</title>
+</head>
+
+<body>
+  <a href="summit-crash.html">Load a crashing page</a>
+</body>
+</html>

src/test/html/summit.html

@@ -0,0 +1,12 @@
+<html>
+  <head>
+    <title>Summit demo page</title>
+  </head>
+<body>
+  <iframe src="about-mozilla.html" style="display:block; border: 1px; width: 400px; height: 400px"
+          frameborder="yes" scrolling="yes"></iframe>
+
+  <iframe src="summit-link.html" style="display:block; border: 1px; width: 400px; height: 400px"
+          frameborder="yes" scrolling="yes"></iframe>
+</body>
+</html>