Reenable send_on_failure for the script task.

src/components/gfx/render_task.rs

@@ -176,7 +176,7 @@ impl<C: RenderListener + Send> RenderTask<C> {
                   shutdown_chan: Sender<()>) {
         let mut builder = task::task().named("RenderTask");
         let ConstellationChan(c) = constellation_chan.clone();
-        send_on_failure(&mut builder, FailureMsg(failure_msg), c);
+        send_on_failure(&mut builder.opts, FailureMsg(failure_msg), c);
         builder.spawn(proc() {
 
             { // Ensures RenderTask and graphics context are destroyed before shutdown msg

src/components/main/layout/layout_task.rs

@@ -289,7 +289,7 @@ impl LayoutTask {
                   shutdown_chan: Sender<()>) {
         let mut builder = task::task().named("LayoutTask");
         let ConstellationChan(con_chan) = constellation_chan.clone();
-        send_on_failure(&mut builder, FailureMsg(failure_msg), con_chan);
+        send_on_failure(&mut builder.opts, FailureMsg(failure_msg), con_chan);
         builder.spawn(proc() {
             { // Ensures layout task is destroyed before we send shutdown message
                 let mut layout = LayoutTask::new(id,

src/components/script/script_task.rs

@@ -46,13 +46,13 @@ use native;
 use servo_msg::compositor_msg::{FinishedLoading, LayerId, Loading, PerformingLayout};
 use servo_msg::compositor_msg::{ScriptListener};
 use servo_msg::constellation_msg::{ConstellationChan, LoadCompleteMsg, LoadUrlMsg, NavigationDirection};
-use servo_msg::constellation_msg::{PipelineId, SubpageId, Failure, /*FailureMsg*/};
+use servo_msg::constellation_msg::{PipelineId, SubpageId, Failure, FailureMsg};
 use servo_msg::constellation_msg;
 use servo_net::image_cache_task::ImageCacheTask;
 use servo_net::resource_task::ResourceTask;
 use servo_util::geometry::to_frac_px;
 use servo_util::url::parse_url;
-//use servo_util::task::send_on_failure;
+use servo_util::task::send_on_failure;
 use servo_util::namespace::Null;
 use std::cast;
 use std::cell::{Cell, RefCell, Ref, RefMut};
@@ -676,7 +676,7 @@ impl ScriptTask {
         let mut opts = task::TaskOpts::new();
         opts.name = Some(Slice("ScriptTask"));
         let ConstellationChan(const_chan) = constellation_chan.clone();
-        //send_on_failure(&mut builder, FailureMsg(failure_msg), const_chan);
+        send_on_failure(&mut opts, FailureMsg(failure_msg), const_chan);
         native::task::spawn_opts(opts, proc() {
             let script_task = ScriptTask::new(id,
                                               compositor as ~ScriptListener,

src/components/util/task.rs

@@ -4,8 +4,8 @@
 
 use std::str::IntoMaybeOwned;
 use std::task;
-use std::comm::Sender;
-use std::task::TaskBuilder;
+use std::comm::{channel, Sender};
+use std::task::TaskOpts;
 
 pub fn spawn_named<S: IntoMaybeOwned<'static>>(name: S, f: proc():Send) {
     let builder = task::task().named(name);
@@ -14,12 +14,14 @@ pub fn spawn_named<S: IntoMaybeOwned<'static>>(name: S, f: proc():Send) {
 
 /// Arrange to send a particular message to a channel if the task built by
 /// this `TaskBuilder` fails.
-pub fn send_on_failure<T: Send>(builder: &mut TaskBuilder, msg: T, dest: Sender<T>) {
-    let port = builder.future_result();
-    let watched_name = builder.opts.name.as_ref().unwrap().as_slice().to_owned();
+pub fn send_on_failure<T: Send>(opts: &mut TaskOpts, msg: T, dest: Sender<T>) {
+    assert!(opts.notify_chan.is_none());
+    let (tx, rx) = channel();
+    opts.notify_chan = Some(tx);
+    let watched_name = opts.name.as_ref().unwrap().as_slice().to_owned();
     let name = format!("{:s}Watcher", watched_name);
     spawn_named(name, proc() {
-        match port.recv() {
+        match rx.recv() {
             Ok(()) => (),
             Err(..) => {
                 debug!("{:s} failed, notifying constellation", watched_name);