Add thaw/freeze messages that can suspend/resume webcontent timers #4907

6 files changed, 105 insertions, 9 deletions

diff --git a/components/compositing/constellation.rs b/components/compositing/constellation.rs
index dedf6e07b5e..daf2cb2503d 100644
--- a/components/compositing/constellation.rs
+++ b/components/compositing/constellation.rs
@@ -834,6 +834,8 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
                                            pipeline.clone(),
                                            parent.borrow().clone())),
                     NavigationType::Load);
+        // Send message to ScriptTask that will suspend all timers
+        source_frame.pipeline.borrow().freeze();
         self.pipelines.insert(pipeline.id, pipeline);
     }
 
@@ -853,6 +855,7 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
                     let old = self.current_frame().as_ref().unwrap();
                     for frame in old.iter() {
                         frame.pipeline.borrow().revoke_paint_permission();
+                        frame.pipeline.borrow().freeze();
                     }
                 }
                 self.navigation_context.forward(&mut *self.compositor_proxy)
@@ -865,6 +868,7 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
                     let old = self.current_frame().as_ref().unwrap();
                     for frame in old.iter() {
                         frame.pipeline.borrow().revoke_paint_permission();
+                        frame.pipeline.borrow().freeze();
                     }
                 }
                 self.navigation_context.back(&mut *self.compositor_proxy)
@@ -873,6 +877,7 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
 
         for frame in destination_frame.iter() {
             frame.pipeline.borrow().load();
+            frame.pipeline.borrow().thaw();
         }
         self.send_frame_tree_and_grant_paint_permission(destination_frame);
 
diff --git a/components/compositing/pipeline.rs b/components/compositing/pipeline.rs
index 9bb29db622f..27ee5eba150 100644
--- a/components/compositing/pipeline.rs
+++ b/components/compositing/pipeline.rs
@@ -191,6 +191,16 @@ impl Pipeline {
 
     }
 
+    pub fn freeze(&self) {
+        let ScriptControlChan(ref script_channel) = self.script_chan;
+        let _ = script_channel.send(ConstellationControlMsg::Freeze(self.id)).unwrap();
+    }
+
+    pub fn thaw(&self) {
+        let ScriptControlChan(ref script_channel) = self.script_chan;
+        let _ = script_channel.send(ConstellationControlMsg::Thaw(self.id)).unwrap();
+    }
+
     pub fn force_exit(&self) {
         let ScriptControlChan(ref script_channel) = self.script_chan;
         let _ = script_channel.send(
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index fcc56776c8d..2ec968ed6e5 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -335,6 +335,8 @@ pub trait WindowHelpers {
     fn load_url(self, href: DOMString);
     fn handle_fire_timer(self, timer_id: TimerId);
     fn IndexedGetter(self, _index: u32, _found: &mut bool) -> Option<Temporary<Window>>;
+    fn thaw(self);
+    fn freeze(self);
 }
 
 pub trait ScriptHelpers {
@@ -404,6 +406,15 @@ impl<'a> WindowHelpers for JSRef<'a, Window> {
     fn IndexedGetter(self, _index: u32, _found: &mut bool) -> Option<Temporary<Window>> {
         None
     }
+
+    fn thaw(self) {
+        self.timers.resume();
+    }
+
+    fn freeze(self) {
+        self.timers.suspend();
+    }
+
 }
 
 impl Window {
diff --git a/components/script/script_task.rs b/components/script/script_task.rs
index 8573efa9d3f..fa397113c9b 100644
--- a/components/script/script_task.rs
+++ b/components/script/script_task.rs
@@ -602,6 +602,10 @@ impl ScriptTask {
                 panic!("should have handled ExitPipeline already"),
             ConstellationControlMsg::GetTitle(pipeline_id) =>
                 self.handle_get_title_msg(pipeline_id),
+            ConstellationControlMsg::Freeze(pipeline_id) =>
+                self.handle_freeze_msg(pipeline_id),
+            ConstellationControlMsg::Thaw(pipeline_id) =>
+                self.handle_thaw_msg(pipeline_id)
         }
     }
 
@@ -685,6 +689,26 @@ impl ScriptTask {
         window.r().handle_fire_timer(timer_id);
     }
 
+    /// Handles freeze message
+    fn handle_freeze_msg(&self, id: PipelineId) {
+        let page = self.page.borrow_mut();
+        let page = page.find(id).expect("ScriptTask: received freeze msg for a
+                    pipeline ID not associated with this script task. This is a bug.");
+        let frame = page.frame();
+        let window = frame.as_ref().unwrap().window.root();
+        window.r().freeze();
+    }
+
+    /// Handles thaw message
+    fn handle_thaw_msg(&self, id: PipelineId) {
+        let page = self.page.borrow_mut();
+        let page = page.find(id).expect("ScriptTask: received thaw msg for a
+                            pipeline ID not associated with this script task. This is a bug.");
+        let frame = page.frame();
+        let window = frame.as_ref().unwrap().window.root();
+        window.r().thaw();
+    }
+
     /// Handles a notification that reflow completed.
     fn handle_reflow_complete_msg(&self, pipeline_id: PipelineId, reflow_id: uint) {
         debug!("Script: Reflow {:?} complete for {:?}", reflow_id, pipeline_id);
diff --git a/components/script/timers.rs b/components/script/timers.rs
index 8f361ebcb7b..59efeeb7959 100644
--- a/components/script/timers.rs
+++ b/components/script/timers.rs
@@ -37,7 +37,7 @@ pub struct TimerId(i32);
 struct TimerHandle {
     handle: TimerId,
     data: TimerData,
-    cancel_chan: Option<Sender<()>>,
+    control_chan: Option<Sender<TimerControlMsg>>,
 }
 
 #[jstraceable]
@@ -56,7 +56,13 @@ impl<H: Writer + Hasher> Hash<H> for TimerId {
 
 impl TimerHandle {
     fn cancel(&mut self) {
-        self.cancel_chan.as_ref().map(|chan| chan.send(()).ok());
+        self.control_chan.as_ref().map(|chan| chan.send(TimerControlMsg::Cancel).ok());
+    }
+    fn suspend(&mut self) {
+        self.control_chan.as_ref().map(|chan| chan.send(TimerControlMsg::Suspend).ok());
+    }
+    fn resume(&mut self) {
+        self.control_chan.as_ref().map(|chan| chan.send(TimerControlMsg::Resume).ok());
     }
 }
 
@@ -85,6 +91,15 @@ pub enum IsInterval {
     NonInterval,
 }
 
+// Messages sent control timers from script task
+#[jstraceable]
+#[derive(PartialEq, Copy, Clone, Show)]
+pub enum TimerControlMsg {
+    Cancel,
+    Suspend,
+    Resume
+}
+
 // Holder for the various JS values associated with setTimeout
 // (ie. function value to invoke and all arguments to pass
 //      to the function when calling it)
@@ -106,6 +121,17 @@ impl TimerManager {
         }
     }
 
+    pub fn suspend(&self) {
+        for (_, timer_handle) in self.active_timers.borrow_mut().iter_mut() {
+            timer_handle.suspend();
+        }
+    }
+    pub fn resume(&self) {
+        for (_, timer_handle) in self.active_timers.borrow_mut().iter_mut() {
+            timer_handle.resume();
+        }
+    }
+
     #[allow(unsafe_blocks)]
     pub fn set_timeout_or_interval(&self,
                                   callback: TimerCallback,
@@ -122,7 +148,7 @@ impl TimerManager {
         // Spawn a new timer task; it will dispatch the `ScriptMsg::FireTimer`
         // to the relevant script handler that will deal with it.
         let tm = Timer::new().unwrap();
-        let (cancel_chan, cancel_port) = channel();
+        let (control_chan, control_port) = channel();
         let spawn_name = match source {
             TimerSource::FromWindow(_) if is_interval == IsInterval::Interval => "Window:SetInterval",
             TimerSource::FromWorker if is_interval == IsInterval::Interval => "Worker:SetInterval",
@@ -137,31 +163,47 @@ impl TimerManager {
             } else {
                 tm.oneshot(duration)
             };
-            let cancel_port = cancel_port;
+            let control_port = control_port;
 
             let select = Select::new();
             let mut timeout_handle = select.handle(&timeout_port);
             unsafe { timeout_handle.add() };
-            let mut cancel_handle = select.handle(&cancel_port);
-            unsafe { cancel_handle.add() };
+            let mut control_handle = select.handle(&control_port);
+            unsafe { control_handle.add() };
 
             loop {
                 let id = select.wait();
+
                 if id == timeout_handle.id() {
                     timeout_port.recv().unwrap();
                     script_chan.send(ScriptMsg::FireTimer(source, TimerId(handle)));
                     if is_interval == IsInterval::NonInterval {
                         break;
                     }
-                } else if id == cancel_handle.id() {
-                    break;
+                } else if id == control_handle.id() {;
+                    match control_port.recv().unwrap() {
+                        TimerControlMsg::Suspend => {
+                            let msg = control_port.recv().unwrap();
+                            match msg {
+                                TimerControlMsg::Suspend => panic!("Nothing to suspend!"),
+                                TimerControlMsg::Resume => {},
+                                TimerControlMsg::Cancel => {
+                                    break;
+                                },
+                            }
+                            },
+                        TimerControlMsg::Resume => panic!("Nothing to resume!"),
+                        TimerControlMsg::Cancel => {
+                            break;
+                        }
+                    }
                 }
             }
         });
         let timer_id = TimerId(handle);
         let timer = TimerHandle {
             handle: timer_id,
-            cancel_chan: Some(cancel_chan),
+            control_chan: Some(control_chan),
             data: TimerData {
                 is_interval: is_interval,
                 callback: callback,
diff --git a/components/script_traits/lib.rs b/components/script_traits/lib.rs
index 6bee3c388d1..aedb11f2dd5 100644
--- a/components/script_traits/lib.rs
+++ b/components/script_traits/lib.rs
@@ -71,6 +71,10 @@ pub enum ConstellationControlMsg {
     Viewport(PipelineId, Rect<f32>),
     /// Requests that the script task immediately send the constellation the title of a pipeline.
     GetTitle(PipelineId),
+    /// Notifies script task to suspend all its timers
+    Freeze(PipelineId),
+    /// Notifies script task to resume all its timers
+    Thaw(PipelineId)
 }
 
 unsafe impl Send for ConstellationControlMsg {