added time to interactive metrics, refactored metrics to use traits

changed task macro to take pipeline info

26 files changed, 727 insertions, 135 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 76930a80186..9ae665974e1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1819,11 +1819,15 @@ dependencies = [
  "gfx 0.0.1",
  "gfx_traits 0.0.1",
  "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "malloc_size_of 0.0.1",
+ "malloc_size_of_derive 0.0.1",
  "msg 0.0.1",
  "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "servo_config 0.0.1",
+ "time 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2416,6 +2420,7 @@ version = "0.0.1"
 dependencies = [
  "energy-monitor 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "energymon 0.3.0 (git+https://github.com/energymon/energymon-rust.git)",
+ "heapsize 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index 417ad6b6877..62b36b1e6fe 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -86,7 +86,7 @@ use layout::wrapper::LayoutNodeLayoutData;
 use layout_traits::LayoutThreadFactory;
 use libc::c_void;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
-use metrics::{PaintTimeMetrics, ProfilerMetadataFactory};
+use metrics::{PaintTimeMetrics, ProfilerMetadataFactory, ProgressiveWebMetric};
 use msg::constellation_msg::PipelineId;
 use msg::constellation_msg::TopLevelBrowsingContextId;
 use net_traits::image_cache::{ImageCache, UsePlaceholder};
diff --git a/components/metrics/Cargo.toml b/components/metrics/Cargo.toml
index 2420d240da2..0393097669b 100644
--- a/components/metrics/Cargo.toml
+++ b/components/metrics/Cargo.toml
@@ -14,7 +14,11 @@ gfx = {path = "../gfx"}
 gfx_traits = {path = "../gfx_traits"}
 ipc-channel = "0.9"
 log = "0.3.5"
+malloc_size_of = { path = "../malloc_size_of" }
+malloc_size_of_derive = { path = "../malloc_size_of_derive" }
 msg = {path = "../msg"}
+lazy_static = "0.2"
 profile_traits = {path = "../profile_traits"}
 script_traits = {path = "../script_traits"}
 servo_config = {path = "../config"}
+time = "0.1"
diff --git a/components/metrics/lib.rs b/components/metrics/lib.rs
index 6a1259ff173..d6a8710fe0f 100644
--- a/components/metrics/lib.rs
+++ b/components/metrics/lib.rs
@@ -1,16 +1,23 @@
 /* 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/. */
+#![feature(custom_attribute)]
 
 extern crate gfx;
 extern crate gfx_traits;
 extern crate ipc_channel;
 #[macro_use]
+extern crate lazy_static;
+#[macro_use]
 extern crate log;
+extern crate malloc_size_of;
+#[macro_use]
+extern crate malloc_size_of_derive;
 extern crate msg;
 extern crate profile_traits;
 extern crate script_traits;
 extern crate servo_config;
+extern crate time;
 
 use gfx::display_list::{DisplayItem, DisplayList};
 use gfx_traits::Epoch;
@@ -18,60 +25,254 @@ use ipc_channel::ipc::IpcSender;
 use msg::constellation_msg::PipelineId;
 use profile_traits::time::{ProfilerChan, ProfilerCategory, send_profile_data};
 use profile_traits::time::TimerMetadata;
-use script_traits::{ConstellationControlMsg, LayoutMsg, PaintMetricType};
+use script_traits::{ConstellationControlMsg, LayoutMsg, PWMType};
 use servo_config::opts;
 use std::cell::{Cell, RefCell};
+use std::cmp::Ordering;
 use std::collections::HashMap;
+use std::time::{Instant, Duration};
+use time::precise_time_ns;
 
 pub trait ProfilerMetadataFactory {
     fn new_metadata(&self) -> Option<TimerMetadata>;
 }
 
-macro_rules! make_time_setter(
-    ( $attr:ident, $func:ident, $category:ident, $label:expr, $metric_type:path ) => (
-        fn $func(&self,
-                 profiler_metadata: Option<TimerMetadata>,
-                 paint_time: f64) {
-            if self.$attr.get().is_some() {
-                return;
-            }
+pub trait ProgressiveWebMetric {
+    fn get_navigation_start(&self) -> Option<f64>;
+    fn set_navigation_start(&mut self, time: f64);
+    fn get_time_profiler_chan(&self) -> &ProfilerChan;
+    fn send_queued_constellation_msg(&self, name: PWMType, time: f64);
+}
+
+lazy_static!{
+    static ref TEN_SECONDS: Duration = Duration::new(10, 0);
+    pub static ref MAX_TASK_TIME: u64 = 50000000;
+}
+
+
+// there should be some requirements on self
+// can i have self<U> ?
+pub fn set_metric<U: ProgressiveWebMetric>(
+    pwm: &U,
+    metadata: Option<TimerMetadata>,
+    metric_type: PWMType,
+    category: ProfilerCategory,
+    attr: &Cell<Option<f64>>,
+    metric_time: Option<f64>,
+) {
+    let navigation_start = match pwm.get_navigation_start() {
+        Some(time) => time,
+        None => {
+            warn!("Trying to set metric before navigation start");
+            return;
+        }
+    };
+
+    let now = match metric_time {
+        Some(time) => time,
+        None => precise_time_ns() as f64,
+    };
+    let time = now - navigation_start;
+    attr.set(Some(time));
+
+    // Queue performance observer notification.
+    pwm.send_queued_constellation_msg(metric_type, time);
+
+    // Send the metric to the time profiler.
+    send_profile_data(
+        category,
+        metadata,
+        &pwm.get_time_profiler_chan(),
+        time as u64,
+        time as u64,
+        0,
+        0,
+    );
+
+    // Print the metric to console if the print-pwm option was given.
+    if opts::get().print_pwm {
+        println!("{:?} {:?}", metric_type, time);
+    }
+
+}
+
+// https://github.com/GoogleChrome/lighthouse/issues/27
+#[derive(MallocSizeOf)]
+pub struct InteractiveMetrics {
+    navigation_start: Cell<Option<f64>>,
+    dom_content_loaded: Cell<Option<f64>>,
+    main_thread_available: Cell<Option<f64>>,
+    time_to_interactive: Cell<Option<f64>>,
+    #[ignore_malloc_size_of = "can't measure channels"]
+    time_profiler_chan: ProfilerChan,
+}
+
+#[derive(Clone, Copy, Debug, MallocSizeOf)]
+pub struct InteractiveWindow {
+    start: u64,
+    #[ignore_malloc_size_of = "don't need to measure rn"] //FIXME
+    instant: Instant,
+    all_interactive: bool,
+}
+
+
+//TODO i don't think all interactive is needed anymore
+impl InteractiveWindow {
+    pub fn new() -> InteractiveWindow {
+        InteractiveWindow {
+            start: precise_time_ns(),
+            instant: Instant::now(),
+            all_interactive: false,
+        }
+    }
+
+    // We need to either start or restart the 10s window
+    //   start: we've added a new document
+    //   restart: there was a task > 50s
+    //   not all documents are interactive
+    pub fn start_window(&mut self) {
+        self.start = precise_time_ns();
+        self.instant = Instant::now();
+        self.unset_all_interactive();
+    }
+
+    pub fn needs_check(&self) -> bool {
+        self.instant.elapsed() > *TEN_SECONDS
+    }
+
+    pub fn check_interactive(&self) -> bool {
+        self.all_interactive
+    }
+
+    pub fn set_all_interactive(&mut self) {
+        self.all_interactive = true;
+    }
+
+    pub fn unset_all_interactive(&mut self) {
+        self.all_interactive = false;
+    }
+
+    pub fn get_start(&self) -> u64 {
+        self.start
+    }
+
+    pub fn elapsed_since_start(&self) -> u64 {
+        self.instant.elapsed().as_secs()
+    }
+
+    // ^^^^^^^^^^^^^ expected u64, found struct `MAX_TASK_TIME`
+
+    pub fn max_task_time() -> u64 {
+        50000000
+    }
+}
+
+#[derive(Debug)]
+pub enum InteractiveFlag {
+    DCL,
+    TTI,
+}
+
+impl InteractiveMetrics {
+    pub fn new(time_profiler_chan: ProfilerChan) -> InteractiveMetrics {
+        InteractiveMetrics {
+            navigation_start: Cell::new(None),
+            dom_content_loaded: Cell::new(None),
+            main_thread_available: Cell::new(None),
+            time_to_interactive: Cell::new(None),
+            time_profiler_chan: time_profiler_chan,
+        }
+    }
 
-            let navigation_start = match self.navigation_start {
-                Some(time) => time,
-                None => {
-                    warn!("Trying to set metric before navigation start");
-                    return;
+    pub fn set_dom_content_loaded(&self) {
+        if self.dom_content_loaded.get().is_none() {
+            self.dom_content_loaded.set(Some(precise_time_ns() as f64));
+        }
+    }
+
+    pub fn set_main_thread_available(&self, time: Option<f64>) {
+        if self.main_thread_available.get().is_none() && time.is_some() {
+            self.main_thread_available.set(time);
+        }
+    }
+
+    pub fn get_dom_content_loaded(&self) -> Option<f64> {
+        self.dom_content_loaded.get()
+    }
+
+    pub fn get_main_thread_available(&self) -> Option<f64> {
+        self.main_thread_available.get()
+    }
+
+    // can set either dlc or tti first, but both must be set to actually calc metric
+    // when the second is set, set_tti is called with appropriate time
+    pub fn maybe_set_tti<T>(
+        &self,
+        profiler_metadata_factory: &T,
+        time: Option<f64>,
+        metric: InteractiveFlag,
+    ) where
+        T: ProfilerMetadataFactory,
+    {
+        if self.get_tti().is_some() {
+            return;
+        }
+        match metric {
+            InteractiveFlag::DCL => self.set_dom_content_loaded(),
+            InteractiveFlag::TTI => self.set_main_thread_available(time),
+        }
+
+        let dcl = self.dom_content_loaded.get();
+        let mta = self.main_thread_available.get();
+        if dcl.is_some() && mta.is_some() {
+            let metric_time = match dcl.unwrap().partial_cmp(&mta.unwrap()) {
+                Some(order) => {
+                    match order {
+                        Ordering::Less => mta,
+                        _ => dcl,
+                    }
                 }
+                None => panic!("no ordering possible. something bad happened"),
             };
+            set_metric(
+                self,
+                profiler_metadata_factory.new_metadata(),
+                PWMType::TimeToInteractive,
+                ProfilerCategory::TimeToInteractive,
+                &self.time_to_interactive,
+                metric_time,
+            );
 
-            let time = paint_time - navigation_start;
-            self.$attr.set(Some(time));
+        }
+    }
 
-            // Queue performance observer notification.
-            let msg = ConstellationControlMsg::PaintMetric(self.pipeline_id,
-                                                           $metric_type,
-                                                           time);
-            if let Err(e) = self.script_chan.send(msg) {
-                warn!("Sending paint metric to script thread failed ({}).", e);
-            }
+    pub fn get_tti(&self) -> Option<f64> {
+        self.time_to_interactive.get()
+    }
+}
 
-            // Send the metric to the time profiler.
-            send_profile_data(ProfilerCategory::$category,
-                              profiler_metadata,
-                              &self.time_profiler_chan,
-                              time as u64, time as u64, 0, 0);
+// TODO don't impl on ref
+impl ProgressiveWebMetric for InteractiveMetrics {
+    fn get_navigation_start(&self) -> Option<f64> {
+        self.navigation_start.get()
+    }
 
-            // Print the metric to console if the print-pwm option was given.
-            if opts::get().print_pwm {
-                println!("{:?} {:?}", $label, time);
-            }
-        }
-    );
-);
+    fn set_navigation_start(&mut self, time: f64) {
+        self.navigation_start.set(Some(time));
+    }
+
+    fn send_queued_constellation_msg(&self, name: PWMType, time: f64) {
+        // TODO
+    }
+
+    fn get_time_profiler_chan(&self) -> &ProfilerChan {
+        &self.time_profiler_chan
+    }
+}
 
 pub struct PaintTimeMetrics {
     pending_metrics: RefCell<HashMap<Epoch, (Option<TimerMetadata>, bool)>>,
-    navigation_start: Option<f64>,
+    navigation_start: Cell<Option<f64>>,
     first_paint: Cell<Option<f64>>,
     first_contentful_paint: Cell<Option<f64>>,
     pipeline_id: PipelineId,
@@ -81,14 +282,15 @@ pub struct PaintTimeMetrics {
 }
 
 impl PaintTimeMetrics {
-    pub fn new(pipeline_id: PipelineId,
-               time_profiler_chan: ProfilerChan,
-               constellation_chan: IpcSender<LayoutMsg>,
-               script_chan: IpcSender<ConstellationControlMsg>)
-        -> PaintTimeMetrics {
+    pub fn new(
+        pipeline_id: PipelineId,
+        time_profiler_chan: ProfilerChan,
+        constellation_chan: IpcSender<LayoutMsg>,
+        script_chan: IpcSender<ConstellationControlMsg>,
+    ) -> PaintTimeMetrics {
         PaintTimeMetrics {
             pending_metrics: RefCell::new(HashMap::new()),
-            navigation_start: None,
+            navigation_start: Cell::new(None),
             first_paint: Cell::new(None),
             first_contentful_paint: Cell::new(None),
             pipeline_id,
@@ -98,24 +300,34 @@ impl PaintTimeMetrics {
         }
     }
 
-    pub fn set_navigation_start(&mut self, time: f64) {
-        self.navigation_start = Some(time);
-    }
+    pub fn maybe_set_first_paint<T>(&self, profiler_metadata_factory: &T)
+    where
+        T: ProfilerMetadataFactory,
+    {
+        {
+            if self.first_paint.get().is_some() {
+                return;
+            }
+        }
 
-    make_time_setter!(first_paint, set_first_paint,
-                      TimeToFirstPaint,
-                      "first-paint",
-                      PaintMetricType::FirstPaint);
-    make_time_setter!(first_contentful_paint, set_first_contentful_paint,
-                      TimeToFirstContentfulPaint,
-                      "first-contentful-paint",
-                      PaintMetricType::FirstContentfulPaint);
+        set_metric(
+            self,
+            profiler_metadata_factory.new_metadata(),
+            PWMType::FirstPaint,
+            ProfilerCategory::TimeToFirstPaint,
+            &self.first_paint,
+            None,
+        );
+    }
 
-    pub fn maybe_observe_paint_time<T>(&self,
-                                       profiler_metadata_factory: &T,
-                                       epoch: Epoch,
-                                       display_list: &DisplayList)
-        where T: ProfilerMetadataFactory {
+    pub fn maybe_observe_paint_time<T>(
+        &self,
+        profiler_metadata_factory: &T,
+        epoch: Epoch,
+        display_list: &DisplayList,
+    ) where
+        T: ProfilerMetadataFactory,
+    {
         if self.first_paint.get().is_some() && self.first_contentful_paint.get().is_some() {
             // If we already set all paint metrics, we just bail out.
             return;
@@ -131,15 +343,15 @@ impl PaintTimeMetrics {
                 &DisplayItem::Image(_) => {
                     is_contentful = true;
                     break;
-                },
+                }
                 _ => (),
             }
         }
 
-        self.pending_metrics.borrow_mut().insert(
-            epoch,
-            (profiler_metadata_factory.new_metadata(), is_contentful)
-        );
+        self.pending_metrics.borrow_mut().insert(epoch, (
+            profiler_metadata_factory.new_metadata(),
+            is_contentful,
+        ));
 
         // Send the pending metric information to the compositor thread.
         // The compositor will record the current time after painting the
@@ -150,9 +362,10 @@ impl PaintTimeMetrics {
         }
     }
 
-    pub fn maybe_set_metric(&mut self, epoch: Epoch, paint_time: f64) {
+    pub fn maybe_set_metric(&self, epoch: Epoch, paint_time: f64) {
         if (self.first_paint.get().is_some() && self.first_contentful_paint.get().is_some()) ||
-           self.navigation_start.is_none() {
+            self.get_navigation_start().is_none()
+        {
             // If we already set all paint metrics or we have not set navigation start yet,
             // we just bail out.
             return;
@@ -160,16 +373,26 @@ impl PaintTimeMetrics {
 
         if let Some(pending_metric) = self.pending_metrics.borrow_mut().remove(&epoch) {
             let profiler_metadata = pending_metric.0;
-            self.set_first_paint(profiler_metadata.clone(), paint_time);
+            set_metric(
+                self,
+                profiler_metadata.clone(),
+                PWMType::FirstPaint,
+                ProfilerCategory::TimeToFirstPaint,
+                &self.first_paint,
+                Some(paint_time),
+            );
+
             if pending_metric.1 {
-                self.set_first_contentful_paint(profiler_metadata, paint_time);
+                set_metric(
+                    self,
+                    profiler_metadata,
+                    PWMType::FirstContentfulPaint,
+                    ProfilerCategory::TimeToFirstContentfulPaint,
+                    &self.first_contentful_paint,
+                    Some(paint_time),
+                );
             }
         }
-
-    }
-
-    pub fn get_navigation_start(&self) -> Option<f64> {
-        self.navigation_start
     }
 
     pub fn get_first_paint(&self) -> Option<f64> {
@@ -180,3 +403,25 @@ impl PaintTimeMetrics {
         self.first_contentful_paint.get()
     }
 }
+
+// TODO don't impl on ref
+impl ProgressiveWebMetric for PaintTimeMetrics {
+    fn get_navigation_start(&self) -> Option<f64> {
+        self.navigation_start.get()
+    }
+
+    fn set_navigation_start(&mut self, time: f64) {
+        self.navigation_start.set(Some(time));
+    }
+
+    fn send_queued_constellation_msg(&self, name: PWMType, time: f64) {
+        let msg = ConstellationControlMsg::PaintMetric(self.pipeline_id, name, time);
+        if let Err(e) = self.script_chan.send(msg) {
+            warn!("Sending metric to script thread failed ({}).", e);
+        }
+    }
+
+    fn get_time_profiler_chan(&self) -> &ProfilerChan {
+        &self.time_profiler_chan
+    }
+}
diff --git a/components/profile/time.rs b/components/profile/time.rs
index cd2aad1d092..c075272fbc0 100644
--- a/components/profile/time.rs
+++ b/components/profile/time.rs
@@ -157,6 +157,7 @@ impl Formattable for ProfilerCategory {
             ProfilerCategory::ScriptPerformanceEvent => "Script Performance Event",
             ProfilerCategory::TimeToFirstPaint => "Time To First Paint",
             ProfilerCategory::TimeToFirstContentfulPaint => "Time To First Contentful Paint",
+            ProfilerCategory::TimeToInteractive => "Time to Interactive",
             ProfilerCategory::ApplicationHeartbeat => "Application Heartbeat",
         };
         format!("{}{}", padding, name)
diff --git a/components/profile_traits/time.rs b/components/profile_traits/time.rs
index 096afa2ead7..3b9316f9478 100644
--- a/components/profile_traits/time.rs
+++ b/components/profile_traits/time.rs
@@ -12,8 +12,8 @@ use signpost;
 
 #[derive(Clone, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
 pub struct TimerMetadata {
-    pub url:         String,
-    pub iframe:      TimerMetadataFrameType,
+    pub url: String,
+    pub iframe: TimerMetadataFrameType,
     pub incremental: TimerMetadataReflowType,
 }
 
@@ -93,6 +93,7 @@ pub enum ProfilerCategory {
     ScriptPerformanceEvent = 0x7b,
     TimeToFirstPaint = 0x80,
     TimeToFirstContentfulPaint = 0x81,
+    TimeToInteractive = 0x82,
     ApplicationHeartbeat = 0x90,
 }
 
@@ -113,7 +114,7 @@ pub fn profile<T, F>(category: ProfilerCategory,
                      profiler_chan: ProfilerChan,
                      callback: F)
                   -> T
-    where F: FnOnce() -> T
+    where F: FnOnce() -> T,
 {
     if opts::get().signpost {
         signpost::start(category as u32, &[0, 0, 0, (category as usize) >> 4]);
diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index 5c7723f17de..6f5dce2ab14 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -61,6 +61,7 @@ use js::glue::{CallObjectTracer, CallValueTracer};
 use js::jsapi::{GCTraceKindToAscii, Heap, JSObject, JSTracer, TraceKind};
 use js::jsval::JSVal;
 use js::rust::Runtime;
+use metrics::{InteractiveMetrics, InteractiveWindow};
 use msg::constellation_msg::{BrowsingContextId, FrameType, PipelineId, TopLevelBrowsingContextId};
 use net_traits::{Metadata, NetworkError, ReferrerPolicy, ResourceThreads};
 use net_traits::filemanager_thread::RelativePos;
@@ -283,7 +284,7 @@ unsafe impl<T: JSTraceable, U: JSTraceable> JSTraceable for Result<T, U> {
 unsafe impl<K, V, S> JSTraceable for HashMap<K, V, S>
     where K: Hash + Eq + JSTraceable,
           V: JSTraceable,
-          S: BuildHasher
+          S: BuildHasher,
 {
     #[inline]
     unsafe fn trace(&self, trc: *mut JSTracer) {
@@ -296,7 +297,7 @@ unsafe impl<K, V, S> JSTraceable for HashMap<K, V, S>
 
 unsafe impl<T, S> JSTraceable for HashSet<T, S>
     where T: Hash + Eq + JSTraceable,
-          S: BuildHasher
+          S: BuildHasher,
 {
     #[inline]
     unsafe fn trace(&self, trc: *mut JSTracer) {
@@ -413,6 +414,8 @@ unsafe_no_jsmanaged_fields!(WebGLVertexArrayId);
 unsafe_no_jsmanaged_fields!(MediaList);
 unsafe_no_jsmanaged_fields!(WebVRGamepadHand);
 unsafe_no_jsmanaged_fields!(ScriptToConstellationChan);
+unsafe_no_jsmanaged_fields!(InteractiveMetrics);
+unsafe_no_jsmanaged_fields!(InteractiveWindow);
 
 unsafe impl<'a> JSTraceable for &'a str {
     #[inline]
diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index 51c52e3f766..bf2077b743f 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -196,7 +196,8 @@ impl DedicatedWorkerGlobalScope {
                     println!("error loading script {}", serialized_worker_url);
                     parent_sender.send(CommonScriptMsg::Task(
                         WorkerEvent,
-                        Box::new(SimpleWorkerErrorHandler::new(worker))
+                        Box::new(SimpleWorkerErrorHandler::new(worker)),
+                        pipeline_id
                     )).unwrap();
                     return;
                 }
@@ -358,6 +359,7 @@ impl DedicatedWorkerGlobalScope {
     #[allow(unsafe_code)]
     pub fn forward_error_to_worker_object(&self, error_info: ErrorInfo) {
         let worker = self.worker.borrow().as_ref().unwrap().clone();
+        let pipeline_id = worker.clone().root().global().pipeline_id();
         let task = Box::new(task!(forward_error_to_worker_object: move || {
             let worker = worker.root();
             let global = worker.global();
@@ -383,7 +385,7 @@ impl DedicatedWorkerGlobalScope {
             }
         }));
         // TODO: Should use the DOM manipulation task source.
-        self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task)).unwrap();
+        self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task, Some(pipeline_id))).unwrap();
     }
 }
 
@@ -404,10 +406,11 @@ impl DedicatedWorkerGlobalScopeMethods for DedicatedWorkerGlobalScope {
     unsafe fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
         let data = StructuredCloneData::write(cx, message)?;
         let worker = self.worker.borrow().as_ref().unwrap().clone();
+        let pipeline_id = worker.clone().root().global().pipeline_id();
         let task = Box::new(task!(post_worker_message: move || {
             Worker::handle_message(worker, data);
         }));
-        self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task)).unwrap();
+        self.parent_sender.send(CommonScriptMsg::Task(WorkerEvent, task, Some(pipeline_id))).unwrap();
         Ok(())
     }
 
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 95408843f07..b9b4542697b 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -99,6 +99,7 @@ use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcSender};
 use js::jsapi::{JSContext, JSRuntime};
 use js::jsapi::JS_GetRuntime;
+use metrics::{InteractiveFlag, InteractiveMetrics, InteractiveWindow, ProfilerMetadataFactory, ProgressiveWebMetric};
 use msg::constellation_msg::{ALT, CONTROL, SHIFT, SUPER};
 use msg::constellation_msg::{BrowsingContextId, Key, KeyModifiers, KeyState, TopLevelBrowsingContextId};
 use net_traits::{FetchResponseMsg, IpcSend, ReferrerPolicy};
@@ -108,6 +109,7 @@ use net_traits::pub_domains::is_pub_domain;
 use net_traits::request::RequestInit;
 use net_traits::response::HttpsState;
 use num_traits::ToPrimitive;
+use profile_traits::time::{TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType};
 use script_layout_interface::message::{Msg, NodesFromPointQueryType, ReflowGoal};
 use script_runtime::{CommonScriptMsg, ScriptThreadEventCategory};
 use script_thread::{MainThreadScriptMsg, ScriptThread};
@@ -360,6 +362,8 @@ pub struct Document {
     /// is inserted or removed from the document.
     /// See https://html.spec.whatwg.org/multipage/#form-owner
     form_id_listener_map: DomRefCell<HashMap<Atom, HashSet<Dom<Element>>>>,
+    interactive_time: DomRefCell<InteractiveMetrics>,
+    tti_window: DomRefCell<InteractiveWindow>,
 }
 
 #[derive(JSTraceable, MallocSizeOf)]
@@ -1834,6 +1838,9 @@ impl Document {
         window.reflow(ReflowGoal::Full, ReflowReason::DOMContentLoaded);
         update_with_current_time_ms(&self.dom_content_loaded_event_end);
 
+        // html parsing has finished - set dom content loaded
+        self.interactive_time.borrow().maybe_set_tti(self, None, InteractiveFlag::DCL);
+
         // Step 4.2.
         // TODO: client message queue.
     }
@@ -1916,6 +1923,14 @@ impl Document {
         self.dom_interactive.get()
     }
 
+    pub fn get_interactive_metrics(&self) -> Ref<InteractiveMetrics> {
+        self.interactive_time.borrow()
+    }
+
+    pub fn is_interactive(&self) -> bool {
+        self.get_interactive_metrics().get_tti().is_some()
+    }
+
     pub fn get_dom_content_loaded_event_start(&self) -> u64 {
         self.dom_content_loaded_event_start.get()
     }
@@ -1936,6 +1951,23 @@ impl Document {
         self.load_event_end.get()
     }
 
+    pub fn start_tti(&self) {
+        self.tti_window.borrow_mut().start_window();
+    }
+
+    /// check tti for this document
+    /// if it's been 10s since this doc encountered a task over 50ms, then we consider the
+    /// main thread available and try to set tti
+    pub fn check_tti(&self) {
+        if self.is_interactive() { return; }
+
+        if self.tti_window.borrow().needs_check() {
+            self.get_interactive_metrics().maybe_set_tti(self,
+                Some(self.tti_window.borrow().get_start() as f64),
+                InteractiveFlag::TTI);
+        }
+    }
+
     // https://html.spec.whatwg.org/multipage/#fire-a-focus-event
     fn fire_focus_event(&self, focus_event_type: FocusEventType, node: &Node, related_target: Option<&EventTarget>) {
         let (event_name, does_bubble) = match focus_event_type {
@@ -2145,6 +2177,9 @@ impl Document {
             (DocumentReadyState::Complete, true)
         };
 
+        let mut interactive_time = InteractiveMetrics::new(window.time_profiler_chan().clone());
+        interactive_time.set_navigation_start(window.get_navigation_start());
+
         Document {
             node: Node::new_document_node(),
             window: Dom::from_ref(window),
@@ -2236,6 +2271,8 @@ impl Document {
             dom_count: Cell::new(1),
             fullscreen_element: MutNullableDom::new(None),
             form_id_listener_map: Default::default(),
+            interactive_time: DomRefCell::new(interactive_time),
+            tti_window: DomRefCell::new(InteractiveWindow::new()),
         }
     }
 
@@ -2579,11 +2616,13 @@ impl Document {
             self.send_to_constellation(event);
         }
 
+        let pipeline_id = self.window().pipeline_id();
+
         // Step 7
         let trusted_pending = Trusted::new(pending);
         let trusted_promise = TrustedPromise::new(promise.clone());
         let handler = ElementPerformFullscreenEnter::new(trusted_pending, trusted_promise, error);
-        let script_msg = CommonScriptMsg::Task(ScriptThreadEventCategory::EnterFullscreen, handler);
+        let script_msg = CommonScriptMsg::Task(ScriptThreadEventCategory::EnterFullscreen, handler, pipeline_id);
         let msg = MainThreadScriptMsg::Common(script_msg);
         window.main_thread_script_chan().send(msg).unwrap();
 
@@ -2615,7 +2654,8 @@ impl Document {
         let trusted_element = Trusted::new(element.r());
         let trusted_promise = TrustedPromise::new(promise.clone());
         let handler = ElementPerformFullscreenExit::new(trusted_element, trusted_promise);
-        let script_msg = CommonScriptMsg::Task(ScriptThreadEventCategory::ExitFullscreen, handler);
+        let pipeline_id = Some(global.pipeline_id());
+        let script_msg = CommonScriptMsg::Task(ScriptThreadEventCategory::ExitFullscreen, handler, pipeline_id);
         let msg = MainThreadScriptMsg::Common(script_msg);
         window.main_thread_script_chan().send(msg).unwrap();
 
@@ -2673,6 +2713,16 @@ impl Element {
     }
 }
 
+impl ProfilerMetadataFactory for Document {
+    fn new_metadata(&self) -> Option<TimerMetadata> {
+        Some(TimerMetadata {
+            url: String::from(self.url().as_str()),
+            iframe: TimerMetadataFrameType::RootWindow,
+            incremental: TimerMetadataReflowType::Incremental,
+        })
+    }
+}
+
 impl DocumentMethods for Document {
     // https://drafts.csswg.org/cssom/#dom-document-stylesheets
     fn StyleSheets(&self) -> DomRoot<StyleSheetList> {
diff --git a/components/script/dom/performancepainttiming.rs b/components/script/dom/performancepainttiming.rs
index 4c25e785208..fb7b8b30209 100644
--- a/components/script/dom/performancepainttiming.rs
+++ b/components/script/dom/performancepainttiming.rs
@@ -9,7 +9,7 @@ use dom::bindings::str::DOMString;
 use dom::globalscope::GlobalScope;
 use dom::performanceentry::PerformanceEntry;
 use dom_struct::dom_struct;
-use script_traits::PaintMetricType;
+use script_traits::PWMType;
 
 #[dom_struct]
 pub struct PerformancePaintTiming {
@@ -17,11 +17,11 @@ pub struct PerformancePaintTiming {
 }
 
 impl PerformancePaintTiming {
-    fn new_inherited(metric_type: PaintMetricType, start_time: f64)
-        -> PerformancePaintTiming {
+    fn new_inherited(metric_type: PWMType, start_time: f64) -> PerformancePaintTiming {
         let name = match metric_type {
-            PaintMetricType::FirstPaint => DOMString::from("first-paint"),
-            PaintMetricType::FirstContentfulPaint => DOMString::from("first-contentful-paint"),
+            PWMType::FirstPaint => DOMString::from("first-paint"),
+            PWMType::FirstContentfulPaint => DOMString::from("first-contentful-paint"),
+            _ => DOMString::from(""),
         };
         PerformancePaintTiming {
             entry: PerformanceEntry::new_inherited(name,
@@ -33,7 +33,7 @@ impl PerformancePaintTiming {
 
     #[allow(unrooted_must_root)]
     pub fn new(global: &GlobalScope,
-               metric_type: PaintMetricType,
+               metric_type: PWMType,
                start_time: f64) -> DomRoot<PerformancePaintTiming> {
         let entry = PerformancePaintTiming::new_inherited(metric_type, start_time);
         reflect_dom_object(Box::new(entry), global, PerformancePaintTimingBinding::Wrap)
diff --git a/components/script/dom/vrdisplay.rs b/components/script/dom/vrdisplay.rs
index d63e0f514e0..55d94412095 100644
--- a/components/script/dom/vrdisplay.rs
+++ b/components/script/dom/vrdisplay.rs
@@ -505,6 +505,7 @@ impl VRDisplay {
             let (raf_sender, raf_receiver) = mpsc::channel();
             let mut near = near_init;
             let mut far = far_init;
+            // let pipeline_id = self.global().pipeline_id().clone(); TODO
 
             // Initialize compositor
             api_sender.send_vr(WebVRCommand::Create(display_id)).unwrap();
@@ -515,7 +516,7 @@ impl VRDisplay {
                 let task = Box::new(task!(handle_vrdisplay_raf: move || {
                     this.root().handle_raf(&sender);
                 }));
-                js_sender.send(CommonScriptMsg::Task(WebVREvent, task)).unwrap();
+                js_sender.send(CommonScriptMsg::Task(WebVREvent, task, None)).unwrap();
 
                 // Run Sync Poses in parallell on Render thread
                 let msg = WebVRCommand::SyncPoses(display_id, near, far, sync_sender.clone());
diff --git a/components/script/dom/websocket.rs b/components/script/dom/websocket.rs
index 47d3a6f3668..a29aed6f246 100644
--- a/components/script/dom/websocket.rs
+++ b/components/script/dom/websocket.rs
@@ -263,9 +263,10 @@ impl WebSocket {
                 address: address,
             });
 
+            let pipeline_id = self.global().pipeline_id();
             self.global()
                 .script_chan()
-                .send(CommonScriptMsg::Task(WebSocketEvent, task))
+                .send(CommonScriptMsg::Task(WebSocketEvent, task, Some(pipeline_id)))
                 .unwrap();
         }
 
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 1df5d6490c8..384c46a04fb 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -304,6 +304,11 @@ impl Window {
         }
     }
 
+    /// Get a sender to the time profiler thread.
+    pub fn time_profiler_chan(&self) -> &TimeProfilerChan {
+        self.globalscope.time_profiler_chan()
+    }
+
     pub fn origin(&self) -> &MutableOrigin {
         self.globalscope.origin()
     }
@@ -1040,6 +1045,10 @@ impl Window {
         }
     }
 
+    pub fn get_navigation_start(&self) -> f64 {
+        self.navigation_start_precise.get()
+    }
+
     /// Cancels all the tasks associated with that window.
     ///
     /// This sets the current `ignore_further_async_events` sentinel value to
@@ -1854,6 +1863,10 @@ impl Window {
             WindowBinding::Wrap(runtime.cx(), win)
         }
     }
+
+    pub fn pipeline_id(&self) -> Option<PipelineId> {
+        Some(self.upcast::<GlobalScope>().pipeline_id())
+    }
 }
 
 fn should_move_clip_rect(clip_rect: Rect<Au>, new_viewport: Rect<f32>) -> bool {
@@ -1962,6 +1975,7 @@ impl Window {
         let _ = self.script_chan.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::DomEvent,
             Box::new(self.task_canceller().wrap_task(task)),
+            self.pipeline_id()
         ));
     }
 }
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 4ebfd67a486..6638f1d1922 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -386,7 +386,7 @@ impl WorkerGlobalScope {
 
     pub fn process_event(&self, msg: CommonScriptMsg) {
         match msg {
-            CommonScriptMsg::Task(_, task) => {
+            CommonScriptMsg::Task(_, task, _) => {
                 task.run_box()
             },
             CommonScriptMsg::CollectReports(reports_chan) => {
diff --git a/components/script/dom/worklet.rs b/components/script/dom/worklet.rs
index ca48ec08fe8..e49163bb799 100644
--- a/components/script/dom/worklet.rs
+++ b/components/script/dom/worklet.rs
@@ -646,7 +646,7 @@ impl WorkletThread {
     where
         T: TaskBox + 'static,
     {
-        let msg = CommonScriptMsg::Task(ScriptThreadEventCategory::WorkletEvent, Box::new(task));
+        let msg = CommonScriptMsg::Task(ScriptThreadEventCategory::WorkletEvent, Box::new(task), None);
         let msg = MainThreadScriptMsg::Common(msg);
         self.global_init.to_script_thread_sender.send(msg).expect("Worklet thread outlived script thread.");
     }
diff --git a/components/script/script_runtime.rs b/components/script/script_runtime.rs
index 7d3e5e60e1c..57e1bbd0755 100644
--- a/components/script/script_runtime.rs
+++ b/components/script/script_runtime.rs
@@ -22,6 +22,7 @@ use js::jsapi::{JSObject, RuntimeOptionsRef, SetPreserveWrapperCallback, SetEnqu
 use js::panic::wrap_panic;
 use js::rust::Runtime as RustRuntime;
 use microtask::{EnqueuedPromiseCallback, Microtask};
+use msg::constellation_msg::PipelineId;
 use profile_traits::mem::{Report, ReportKind, ReportsChan};
 use script_thread::trace_thread;
 use servo_config::opts;
@@ -44,14 +45,14 @@ pub enum CommonScriptMsg {
     /// supplied channel.
     CollectReports(ReportsChan),
     /// Generic message that encapsulates event handling.
-    Task(ScriptThreadEventCategory, Box<TaskBox>),
+    Task(ScriptThreadEventCategory, Box<TaskBox>, Option<PipelineId>),
 }
 
 impl fmt::Debug for CommonScriptMsg {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             CommonScriptMsg::CollectReports(_) => write!(f, "CollectReports(...)"),
-            CommonScriptMsg::Task(ref category, ref task) => {
+            CommonScriptMsg::Task(ref category, ref task, _) => {
                 f.debug_tuple("Task").field(category).field(task).finish()
             },
         }
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 1a45b08e54b..1fe8c47b7bc 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -16,6 +16,7 @@
 //! takes over the response body. Once parsing is complete, the document lifecycle for loading
 //! a page runs its course and the script thread returns to processing events in the main event
 //! loop.
+#![feature(box_syntax)]
 
 use bluetooth_traits::BluetoothRequest;
 use canvas_traits::webgl::WebGLPipeline;
@@ -74,7 +75,7 @@ use js::jsapi::{JSTracer, SetWindowProxyClass};
 use js::jsval::UndefinedValue;
 use malloc_size_of::MallocSizeOfOps;
 use mem::malloc_size_of_including_self;
-use metrics::PaintTimeMetrics;
+use metrics::{InteractiveWindow, PaintTimeMetrics};
 use microtask::{MicrotaskQueue, Microtask};
 use msg::constellation_msg::{BrowsingContextId, FrameType, PipelineId, PipelineNamespace, TopLevelBrowsingContextId};
 use net_traits::{FetchMetadata, FetchResponseListener, FetchResponseMsg};
@@ -91,7 +92,7 @@ use script_traits::{CompositorEvent, ConstellationControlMsg};
 use script_traits::{DiscardBrowsingContext, DocumentActivity, EventResult};
 use script_traits::{InitialScriptState, JsEvalResult, LayoutMsg, LoadData};
 use script_traits::{MouseButton, MouseEventType, MozBrowserEvent, NewLayoutInfo};
-use script_traits::{PaintMetricType, Painter, ScriptMsg, ScriptThreadFactory};
+use script_traits::{PWMType, Painter, ScriptMsg, ScriptThreadFactory};
 use script_traits::{ScriptToConstellationChan, TimerEvent, TimerSchedulerMsg};
 use script_traits::{TimerSource, TouchEventType, TouchId, UntrustedNodeAddress};
 use script_traits::{UpdatePipelineIdReason, WindowSizeData, WindowSizeType};
@@ -345,6 +346,10 @@ impl Documents {
         self.map.get(&pipeline_id).map(|doc| DomRoot::from_ref(&**doc))
     }
 
+    pub fn len(&self) -> usize {
+        self.map.len()
+    }
+
     pub fn find_window(&self, pipeline_id: PipelineId) -> Option<DomRoot<Window>> {
         self.find_document(pipeline_id).map(|doc| DomRoot::from_ref(doc.window()))
     }
@@ -681,7 +686,8 @@ impl ScriptThread {
         SCRIPT_THREAD_ROOT.with(|root| {
             if let Some(script_thread) = root.get() {
                 let script_thread = unsafe { &*script_thread };
-                script_thread.profile_event(ScriptThreadEventCategory::AttachLayout, || {
+                let p_id = Some(new_layout_info.new_pipeline_id);
+                script_thread.profile_event(ScriptThreadEventCategory::AttachLayout, p_id, || {
                     script_thread.handle_new_layout(new_layout_info, origin);
                 })
             }
@@ -727,8 +733,8 @@ impl ScriptThread {
         pipeline_id: PipelineId,
         name: Atom,
         properties: Vec<Atom>,
-        painter: Box<Painter>,
-    ) {
+        painter: Box<Painter>)
+    {
         let window = self.documents.borrow().find_window(pipeline_id);
         let window = match window {
             Some(window) => window,
@@ -840,7 +846,7 @@ impl ScriptThread {
             control_chan: state.control_chan,
             control_port: control_port,
             script_sender: state.script_to_constellation_chan.sender.clone(),
-            time_profiler_chan: state.time_profiler_chan,
+            time_profiler_chan: state.time_profiler_chan.clone(),
             mem_profiler_chan: state.mem_profiler_chan,
 
             devtools_chan: state.devtools_chan,
@@ -964,7 +970,8 @@ impl ScriptThread {
                 // child list yet, causing the find() to fail.
                 FromConstellation(ConstellationControlMsg::AttachLayout(
                         new_layout_info)) => {
-                    self.profile_event(ScriptThreadEventCategory::AttachLayout, || {
+                    //FIXME there should be a pipeline id
+                    self.profile_event(ScriptThreadEventCategory::AttachLayout, None, || {
                         // If this is an about:blank load, it must share the creator's origin.
                         // This must match the logic in the constellation when creating a new pipeline
                         let origin = if new_layout_info.load_data.url.as_str() != "about:blank" {
@@ -986,17 +993,17 @@ impl ScriptThread {
                 }
                 FromConstellation(ConstellationControlMsg::Resize(id, size, size_type)) => {
                     // step 7.7
-                    self.profile_event(ScriptThreadEventCategory::Resize, || {
+                    self.profile_event(ScriptThreadEventCategory::Resize, Some(id), || {
                         self.handle_resize(id, size, size_type);
                     })
                 }
                 FromConstellation(ConstellationControlMsg::Viewport(id, rect)) => {
-                    self.profile_event(ScriptThreadEventCategory::SetViewport, || {
+                    self.profile_event(ScriptThreadEventCategory::SetViewport, Some(id), || {
                         self.handle_viewport(id, rect);
                     })
                 }
                 FromConstellation(ConstellationControlMsg::SetScrollState(id, scroll_state)) => {
-                    self.profile_event(ScriptThreadEventCategory::SetScrollState, || {
+                    self.profile_event(ScriptThreadEventCategory::SetScrollState, Some(id), || {
                         self.handle_set_scroll_state(id, &scroll_state);
                     })
                 }
@@ -1051,9 +1058,11 @@ impl ScriptThread {
         debug!("Processing events.");
         for msg in sequential {
             debug!("Processing event {:?}.", msg);
+
             let category = self.categorize_msg(&msg);
+            let p_id = self.message_to_pipeline(&msg);
 
-            let result = self.profile_event(category, move || {
+            let result = self.profile_event(category, p_id, move || {
                 match msg {
                     FromConstellation(ConstellationControlMsg::ExitScriptThread) => {
                         self.handle_exit_script_thread_msg();
@@ -1122,7 +1131,7 @@ impl ScriptThread {
             MixedMessage::FromImageCache(_) => ScriptThreadEventCategory::ImageCacheMsg,
             MixedMessage::FromScript(ref inner_msg) => {
                 match *inner_msg {
-                    MainThreadScriptMsg::Common(CommonScriptMsg::Task(category, _)) => {
+                    MainThreadScriptMsg::Common(CommonScriptMsg::Task(category, ..)) => {
                         category
                     },
                     MainThreadScriptMsg::RegisterPaintWorklet { .. } => {
@@ -1135,7 +1144,67 @@ impl ScriptThread {
         }
     }
 
-    fn profile_event<F, R>(&self, category: ScriptThreadEventCategory, f: F) -> R
+    fn message_to_pipeline(&self, msg: &MixedMessage) -> Option<PipelineId> {
+        use script_traits::ConstellationControlMsg::*;
+        match *msg {
+            MixedMessage::FromConstellation(ref inner_msg) => {
+                match *inner_msg {
+                    NavigationResponse(id, _) => Some(id),
+                    AttachLayout(ref new_layout_info) => Some(new_layout_info.new_pipeline_id),
+                    Resize(id, ..) => Some(id),
+                    ResizeInactive(id, ..) => Some(id),
+                    ExitPipeline(id, ..) => Some(id),
+                    ExitScriptThread => None,
+                    SendEvent(id, ..) => Some(id),
+                    Viewport(id, ..) => Some(id),
+                    SetScrollState(id, ..) => Some(id),
+                    GetTitle(id) => Some(id),
+                    SetDocumentActivity(id, ..) => Some(id),
+                    ChangeFrameVisibilityStatus(id, ..) => Some(id),
+                    NotifyVisibilityChange(id, ..) => Some(id),
+                    Navigate(id, ..) => Some(id),
+                    PostMessage(id, ..) => Some(id),
+                    MozBrowserEvent(id, ..) => Some(id),
+                    UpdatePipelineId(_, _, id, _) => Some(id),
+                    FocusIFrame(id, ..) => Some(id),
+                    WebDriverScriptCommand(id, ..) => Some(id),
+                    TickAllAnimations(id) => Some(id),
+                    TransitionEnd(..) => None,
+                    WebFontLoaded(id) => Some(id),
+                    DispatchIFrameLoadEvent { .. } => None,
+                    DispatchStorageEvent(id, ..) => Some(id),
+                    ReportCSSError(id, ..) => Some(id),
+                    Reload(id, ..) => Some(id),
+                    WebVREvents(id, ..) => Some(id),
+                    PaintMetric(..) => None,
+                    InteractiveMetric(..) => None,
+                }
+            },
+            MixedMessage::FromDevtools(_) => None,
+            MixedMessage::FromScript(ref inner_msg) => {
+                match *inner_msg {
+                    MainThreadScriptMsg::Common(CommonScriptMsg::Task(_, _, pipeline_id)) =>
+                        pipeline_id,
+                    MainThreadScriptMsg::Common(_) => None, //TODO double check
+                    MainThreadScriptMsg::ExitWindow(pipeline_id) => Some(pipeline_id),
+                    MainThreadScriptMsg::Navigate(pipeline_id, ..) => Some(pipeline_id),
+                    MainThreadScriptMsg::WorkletLoaded(pipeline_id) => Some(pipeline_id),
+                    MainThreadScriptMsg::RegisterPaintWorklet { pipeline_id, .. } => Some(pipeline_id),
+                    MainThreadScriptMsg::DispatchJobQueue { .. }  => None,
+                }
+            },
+            MixedMessage::FromImageCache((pipeline_id, _)) => Some(pipeline_id),
+            MixedMessage::FromScheduler(ref timer_event) => {
+                let TimerEvent(source, _) = *timer_event;
+                match source {
+                    TimerSource::FromWindow(pipeline_id) => Some(pipeline_id),
+                    _ => None
+                }
+            }
+        }
+    }
+
+    fn profile_event<F, R>(&self, category: ScriptThreadEventCategory, p_id: Option<PipelineId>, f: F) -> R
         where F: FnOnce() -> R {
         if opts::get().profile_script_events {
             let profiler_cat = match category {
@@ -1169,7 +1238,24 @@ impl ScriptThread {
                 ScriptThreadEventCategory::ExitFullscreen => ProfilerCategory::ScriptExitFullscreen,
                 ScriptThreadEventCategory::PerformanceTimelineTask => ProfilerCategory::ScriptPerformanceEvent,
             };
-            profile(profiler_cat, None, self.time_profiler_chan.clone(), f)
+
+            let start = precise_time_ns();
+            let t = profile(profiler_cat, None, self.time_profiler_chan.clone(), f);
+            let end = precise_time_ns();
+            debug!("Task {:?} took {}", category, end - start);       // TODO do we want to do anything with this?
+
+            for (doc_id, doc) in self.documents.borrow().iter() {
+                match p_id {
+                    Some(p_id) => {
+                        if p_id == doc_id && end - start > InteractiveWindow::max_task_time() {
+                            doc.start_tti()
+                        }
+                    },
+                    _ => ()
+                }
+                doc.check_tti();
+            }
+            t
         } else {
             f()
         }
@@ -1240,6 +1326,7 @@ impl ScriptThread {
                 self.handle_webvr_events(pipeline_id, events),
             ConstellationControlMsg::PaintMetric(pipeline_id, metric_type, metric_value) =>
                 self.handle_paint_metric(pipeline_id, metric_type, metric_value),
+            ConstellationControlMsg::InteractiveMetric(pipeline_id, metric_value) => (),  //TODO
             msg @ ConstellationControlMsg::AttachLayout(..) |
             msg @ ConstellationControlMsg::Viewport(..) |
             msg @ ConstellationControlMsg::SetScrollState(..) |
@@ -1257,7 +1344,7 @@ impl ScriptThread {
             MainThreadScriptMsg::ExitWindow(id) => {
                 self.handle_exit_window_msg(id)
             },
-            MainThreadScriptMsg::Common(CommonScriptMsg::Task(_, task)) => {
+            MainThreadScriptMsg::Common(CommonScriptMsg::Task(_, task, _)) => {
                 task.run_box()
             }
             MainThreadScriptMsg::Common(CommonScriptMsg::CollectReports(chan)) => {
@@ -2563,7 +2650,7 @@ impl ScriptThread {
 
     fn handle_paint_metric(&self,
                            pipeline_id: PipelineId,
-                           metric_type: PaintMetricType,
+                           metric_type: PWMType,
                            metric_value: f64) {
         let window = self.documents.borrow().find_window(pipeline_id);
         if let Some(window) = window {
diff --git a/components/script/task_source/dom_manipulation.rs b/components/script/task_source/dom_manipulation.rs
index 5eb20d2d274..16db9310693 100644
--- a/components/script/task_source/dom_manipulation.rs
+++ b/components/script/task_source/dom_manipulation.rs
@@ -37,6 +37,7 @@ impl TaskSource for DOMManipulationTaskSource {
         let msg = MainThreadScriptMsg::Common(CommonScriptMsg::Task(
             ScriptThreadEventCategory::ScriptEvent,
             Box::new(canceller.wrap_task(task)),
+            None    //TODO
         ));
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/components/script/task_source/file_reading.rs b/components/script/task_source/file_reading.rs
index fe2ae2e4d17..8f4cdd80ac3 100644
--- a/components/script/task_source/file_reading.rs
+++ b/components/script/task_source/file_reading.rs
@@ -30,6 +30,7 @@ impl TaskSource for FileReadingTaskSource {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::FileRead,
             Box::new(canceller.wrap_task(task)),
+            None    //TODO
         ))
     }
 }
diff --git a/components/script/task_source/networking.rs b/components/script/task_source/networking.rs
index 41795227e5d..0c2fd8f6162 100644
--- a/components/script/task_source/networking.rs
+++ b/components/script/task_source/networking.rs
@@ -27,6 +27,7 @@ impl TaskSource for NetworkingTaskSource {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::NetworkEvent,
             Box::new(canceller.wrap_task(task)),
+            None
         ))
     }
 }
@@ -41,6 +42,7 @@ impl NetworkingTaskSource {
         self.0.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::NetworkEvent,
             Box::new(task),
+            None                //TODO
         ))
     }
 }
diff --git a/components/script/task_source/performance_timeline.rs b/components/script/task_source/performance_timeline.rs
index 0de171c4949..a91865cf02f 100644
--- a/components/script/task_source/performance_timeline.rs
+++ b/components/script/task_source/performance_timeline.rs
@@ -40,7 +40,8 @@ impl TaskSource for PerformanceTimelineTaskSource {
     {
         let msg = CommonScriptMsg::Task(
             ScriptThreadEventCategory::PerformanceTimelineTask,
-            Box::new(canceller.wrap_task(task))
+            Box::new(canceller.wrap_task(task)),
+            None
         );
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/components/script/task_source/user_interaction.rs b/components/script/task_source/user_interaction.rs
index c10e870ac7e..ba90a26a080 100644
--- a/components/script/task_source/user_interaction.rs
+++ b/components/script/task_source/user_interaction.rs
@@ -37,6 +37,7 @@ impl TaskSource for UserInteractionTaskSource {
         let msg = MainThreadScriptMsg::Common(CommonScriptMsg::Task(
             ScriptThreadEventCategory::InputEvent,
             Box::new(canceller.wrap_task(task)),
+            None
         ));
         self.0.send(msg).map_err(|_| ())
     }
diff --git a/components/script_traits/lib.rs b/components/script_traits/lib.rs
index a4e3634296d..f2210cfd76d 100644
--- a/components/script_traits/lib.rs
+++ b/components/script_traits/lib.rs
@@ -231,13 +231,15 @@ pub enum DocumentActivity {
     FullyActive,
 }
 
-/// The type of recorded paint metric.
-#[derive(Deserialize, Serialize)]
-pub enum PaintMetricType {
-    /// Time to First Paint type.
+/// Type of recorded progressive web metric
+#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+pub enum PWMType {
+    /// Time to first Paint
     FirstPaint,
-    /// Time to First Contentful Paint type.
+    /// Time to first contentful paint
     FirstContentfulPaint,
+    /// Time to interactive
+    TimeToInteractive,
 }
 
 /// The reason why the pipeline id of an iframe is being updated.
@@ -322,7 +324,9 @@ pub enum ConstellationControlMsg {
     /// Notifies the script thread of WebVR events.
     WebVREvents(PipelineId, Vec<WebVREvent>),
     /// Notifies the script thread about a new recorded paint metric.
-    PaintMetric(PipelineId, PaintMetricType, f64),
+    PaintMetric(PipelineId, PWMType, f64),
+    /// Notifies the script thread of interactive time
+    InteractiveMetric(PipelineId, f64),
 }
 
 impl fmt::Debug for ConstellationControlMsg {
@@ -357,6 +361,7 @@ impl fmt::Debug for ConstellationControlMsg {
             Reload(..) => "Reload",
             WebVREvents(..) => "WebVREvents",
             PaintMetric(..) => "PaintMetric",
+            InteractiveMetric(..) => "InteractiveMetric"
         };
         write!(formatter, "ConstellationMsg::{}", variant)
     }
diff --git a/tests/unit/metrics/interactive_time.rs b/tests/unit/metrics/interactive_time.rs
new file mode 100644
index 00000000000..5652ffbe06d
--- /dev/null
+++ b/tests/unit/metrics/interactive_time.rs
@@ -0,0 +1,116 @@
+/* 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/. */
+
+use ipc_channel::ipc;
+use metrics::{InteractiveMetrics, InteractiveFlag, InteractiveWindow};
+use metrics::{ProfilerMetadataFactory, ProgressiveWebMetric};
+use profile_traits::time::{ProfilerChan, TimerMetadata};
+use time;
+
+struct DummyProfilerMetadataFactory {}
+impl ProfilerMetadataFactory for DummyProfilerMetadataFactory {
+    fn new_metadata(&self) -> Option<TimerMetadata> {
+        None
+    }
+}
+
+
+fn test_interactive() -> InteractiveMetrics {
+    let (sender, _) = ipc::channel().unwrap();
+    let profiler_chan = ProfilerChan(sender);
+    let mut interactive = InteractiveMetrics::new(profiler_chan);
+
+    assert_eq!((&interactive).get_navigation_start(), None);
+    assert_eq!(interactive.get_tti(), None);
+
+    interactive.set_navigation_start(time::precise_time_ns() as f64);
+
+    interactive
+}
+
+#[test]
+fn test_set_dcl() {
+    let profiler_metadata_factory = DummyProfilerMetadataFactory {};
+
+    let interactive = test_interactive();
+    interactive.maybe_set_tti(&profiler_metadata_factory, None, InteractiveFlag::DCL);
+    let dcl = interactive.get_dom_content_loaded();
+    assert!(dcl.is_some());
+
+    //try to overwrite
+    interactive.maybe_set_tti(&profiler_metadata_factory, None, InteractiveFlag::DCL);
+    assert_eq!(interactive.get_dom_content_loaded(), dcl);
+    assert_eq!(interactive.get_tti(), None);
+}
+
+#[test]
+fn test_set_mta() {
+    let profiler_metadata_factory = DummyProfilerMetadataFactory {};
+
+    let interactive = test_interactive();
+    let t = time::precise_time_ns();
+    interactive.maybe_set_tti(
+        &profiler_metadata_factory,
+        Some(t as f64),
+        InteractiveFlag::TTI,
+    );
+    let mta = interactive.get_main_thread_available();
+    assert!(mta.is_some());
+    assert_eq!(mta, Some(t as f64));
+
+    //try to overwrite
+    interactive.maybe_set_tti(
+        &profiler_metadata_factory,
+        Some(time::precise_time_ns() as f64),
+        InteractiveFlag::TTI,
+    );
+    assert_eq!(interactive.get_main_thread_available(), mta);
+    assert_eq!(interactive.get_tti(), None);
+}
+
+#[test]
+fn test_set_tti_dcl() {
+    let profiler_metadata_factory = DummyProfilerMetadataFactory {};
+
+    let interactive = test_interactive();
+    let t = time::precise_time_ns();
+    interactive.maybe_set_tti(
+        &profiler_metadata_factory,
+        Some(t as f64),
+        InteractiveFlag::TTI,
+    );
+    let mta = interactive.get_main_thread_available();
+    assert!(mta.is_some());
+
+    interactive.maybe_set_tti(&profiler_metadata_factory, None, InteractiveFlag::DCL);
+    let dcl = interactive.get_dom_content_loaded();
+    assert!(dcl.is_some());
+
+    let interactive_time = dcl.unwrap() - (&interactive).get_navigation_start().unwrap();
+    assert_eq!(interactive.get_tti(), Some(interactive_time));
+}
+
+#[test]
+fn test_set_tti_mta() {
+    let profiler_metadata_factory = DummyProfilerMetadataFactory {};
+
+    let interactive = test_interactive();
+    interactive.maybe_set_tti(&profiler_metadata_factory, None, InteractiveFlag::DCL);
+    let dcl = interactive.get_dom_content_loaded();
+    assert!(dcl.is_some());
+
+    let t = time::precise_time_ns();
+    interactive.maybe_set_tti(
+        &profiler_metadata_factory,
+        Some(t as f64),
+        InteractiveFlag::TTI,
+    );
+    let mta = interactive.get_main_thread_available();
+    assert!(mta.is_some());
+
+    let interactive_time = mta.unwrap() - (&interactive).get_navigation_start().unwrap();
+    assert_eq!(interactive.get_tti(), Some(interactive_time));
+}
+
+// TODO InteractiveWindow tests
diff --git a/tests/unit/metrics/lib.rs b/tests/unit/metrics/lib.rs
index bde61912493..fc5456a271c 100644
--- a/tests/unit/metrics/lib.rs
+++ b/tests/unit/metrics/lib.rs
@@ -14,4 +14,5 @@ extern crate style;
 extern crate time;
 
 #[cfg(test)]
+mod interactive_time;
 mod paint_time;
diff --git a/tests/unit/metrics/paint_time.rs b/tests/unit/metrics/paint_time.rs
index 2148c71f3ee..8af87a33c51 100644
--- a/tests/unit/metrics/paint_time.rs
+++ b/tests/unit/metrics/paint_time.rs
@@ -7,7 +7,7 @@ use gfx::display_list::{BaseDisplayItem, WebRenderImageInfo};
 use gfx::display_list::{DisplayItem, DisplayList, ImageDisplayItem};
 use gfx_traits::Epoch;
 use ipc_channel::ipc;
-use metrics::{PaintTimeMetrics, ProfilerMetadataFactory};
+use metrics::{PaintTimeMetrics, ProfilerMetadataFactory, ProgressiveWebMetric};
 use msg::constellation_msg::TEST_PIPELINE_ID;
 use net_traits::image::base::PixelFormat;
 use profile_traits::time::{ProfilerChan, TimerMetadata};
@@ -27,10 +27,27 @@ fn test_paint_metrics_construction() {
     let profiler_chan = ProfilerChan(sender);
     let (layout_sender, _) = ipc::channel().unwrap();
     let (script_sender, _) = ipc::channel().unwrap();
-    let paint_time_metrics = PaintTimeMetrics::new(TEST_PIPELINE_ID, profiler_chan, layout_sender, script_sender);
-    assert_eq!(paint_time_metrics.get_navigation_start(), None, "navigation start is None");
-    assert_eq!(paint_time_metrics.get_first_paint(), None, "first paint is None");
-    assert_eq!(paint_time_metrics.get_first_contentful_paint(), None, "first contentful paint is None");
+    let paint_time_metrics = PaintTimeMetrics::new(
+        TEST_PIPELINE_ID,
+        profiler_chan,
+        layout_sender,
+        script_sender,
+    );
+    assert_eq!(
+        (&paint_time_metrics).get_navigation_start(),
+        None,
+        "navigation start is None"
+    );
+    assert_eq!(
+        paint_time_metrics.get_first_paint(),
+        None,
+        "first paint is None"
+    );
+    assert_eq!(
+        paint_time_metrics.get_first_contentful_paint(),
+        None,
+        "first contentful paint is None"
+    );
 }
 
 fn test_common(display_list: &DisplayList, epoch: Epoch) -> PaintTimeMetrics {
@@ -38,22 +55,40 @@ fn test_common(display_list: &DisplayList, epoch: Epoch) -> PaintTimeMetrics {
     let profiler_chan = ProfilerChan(sender);
     let (layout_sender, _) = ipc::channel().unwrap();
     let (script_sender, _) = ipc::channel().unwrap();
-    let mut paint_time_metrics = PaintTimeMetrics::new(TEST_PIPELINE_ID, profiler_chan, layout_sender, script_sender);
+    let mut paint_time_metrics = PaintTimeMetrics::new(
+        TEST_PIPELINE_ID,
+        profiler_chan,
+        layout_sender,
+        script_sender,
+    );
     let dummy_profiler_metadata_factory = DummyProfilerMetadataFactory {};
 
-    paint_time_metrics.maybe_observe_paint_time(&dummy_profiler_metadata_factory,
-                                                epoch,
-                                                &display_list);
+    paint_time_metrics.maybe_observe_paint_time(
+        &dummy_profiler_metadata_factory,
+        epoch,
+        &display_list,
+    );
 
     // Should not set any metric until navigation start is set.
     paint_time_metrics.maybe_set_metric(epoch, 0.);
-    assert_eq!(paint_time_metrics.get_first_paint(), None, "first paint is None");
-    assert_eq!(paint_time_metrics.get_first_contentful_paint(), None, "first contentful paint is None");
+    assert_eq!(
+        paint_time_metrics.get_first_paint(),
+        None,
+        "first paint is None"
+    );
+    assert_eq!(
+        paint_time_metrics.get_first_contentful_paint(),
+        None,
+        "first contentful paint is None"
+    );
 
     let navigation_start = time::precise_time_ns() as f64;
     paint_time_metrics.set_navigation_start(navigation_start);
-    assert_eq!(paint_time_metrics.get_navigation_start().unwrap(),
-               navigation_start, "navigation start is set");
+    assert_eq!(
+        (&paint_time_metrics).get_navigation_start().unwrap(),
+        navigation_start,
+        "navigation start is set"
+    );
 
     paint_time_metrics
 }
@@ -68,8 +103,15 @@ fn test_first_paint_setter() {
     let mut paint_time_metrics = test_common(&empty_display_list, epoch);
     let now = time::precise_time_ns() as f64;
     paint_time_metrics.maybe_set_metric(epoch, now);
-    assert!(paint_time_metrics.get_first_paint().is_some(), "first paint is set");
-    assert_eq!(paint_time_metrics.get_first_contentful_paint(), None, "first contentful paint is None");
+    assert!(
+        paint_time_metrics.get_first_paint().is_some(),
+        "first paint is set"
+    );
+    assert_eq!(
+        paint_time_metrics.get_first_contentful_paint(),
+        None,
+        "first contentful paint is None"
+    );
 }
 
 #[test]
@@ -95,6 +137,12 @@ fn test_first_contentful_paint_setter() {
     let mut paint_time_metrics = test_common(&display_list, epoch);
     let now = time::precise_time_ns() as f64;
     paint_time_metrics.maybe_set_metric(epoch, now);
-    assert!(paint_time_metrics.get_first_contentful_paint().is_some(), "first contentful paint is set");
-    assert!(paint_time_metrics.get_first_paint().is_some(), "first paint is set");
+    assert!(
+        paint_time_metrics.get_first_contentful_paint().is_some(),
+        "first contentful paint is set"
+    );
+    assert!(
+        paint_time_metrics.get_first_paint().is_some(),
+        "first paint is set"
+    );
 }