restructure content process shutdown ack with threaded sender, without layout

components/constellation/pipeline.rs

@@ -9,7 +9,7 @@ use canvas_traits::webgl::WebGLPipeline;
 use compositing::compositor_thread::Msg as CompositorMsg;
 use compositing::CompositionPipeline;
 use compositing::CompositorProxy;
-use crossbeam_channel::Sender;
+use crossbeam_channel::{unbounded, Sender};
 use devtools_traits::{DevtoolsControlMsg, ScriptToDevtoolsControlMsg};
 use embedder_traits::EventLoopWaker;
 use euclid::{Scale, Size2D};
@@ -218,9 +218,6 @@ impl Pipeline {
         // probably requires a general low-memory strategy.
         let (pipeline_chan, pipeline_port) = ipc::channel().expect("Pipeline main chan");
 
-        let (layout_content_process_shutdown_chan, layout_content_process_shutdown_port) =
-            ipc::channel().expect("Pipeline layout content shutdown chan");
-
         let window_size = WindowSizeData {
             initial_viewport: state.window_size,
             device_pixel_ratio: state.device_pixel_ratio,
@@ -237,7 +234,6 @@ impl Pipeline {
                     load_data: state.load_data.clone(),
                     window_size: window_size,
                     pipeline_port: pipeline_port,
-                    content_process_shutdown_chan: Some(layout_content_process_shutdown_chan),
                 };
 
                 if let Err(e) =
@@ -275,9 +271,6 @@ impl Pipeline {
                     script_to_devtools_chan
                 });
 
-                let (script_content_process_shutdown_chan, script_content_process_shutdown_port) =
-                    ipc::channel().expect("Pipeline script content process shutdown chan");
-
                 let mut unprivileged_pipeline_content = UnprivilegedPipelineContent {
                     id: state.id,
                     browsing_context_id: state.browsing_context_id,
@@ -306,10 +299,6 @@ impl Pipeline {
                     prefs: prefs::pref_map().iter().collect(),
                     pipeline_port: pipeline_port,
                     pipeline_namespace_id: state.pipeline_namespace_id,
-                    layout_content_process_shutdown_chan: layout_content_process_shutdown_chan,
-                    layout_content_process_shutdown_port: layout_content_process_shutdown_port,
-                    script_content_process_shutdown_chan: script_content_process_shutdown_chan,
-                    script_content_process_shutdown_port: script_content_process_shutdown_port,
                     webrender_api_sender: state.webrender_api_sender,
                     webrender_document: state.webrender_document,
                     webgl_chan: state.webgl_chan,
@@ -515,10 +504,6 @@ pub struct UnprivilegedPipelineContent {
     prefs: HashMap<String, PrefValue>,
     pipeline_port: IpcReceiver<LayoutControlMsg>,
     pipeline_namespace_id: PipelineNamespaceId,
-    layout_content_process_shutdown_chan: IpcSender<()>,
-    layout_content_process_shutdown_port: IpcReceiver<()>,
-    script_content_process_shutdown_chan: IpcSender<()>,
-    script_content_process_shutdown_port: IpcReceiver<()>,
     webrender_api_sender: webrender_api::RenderApiSender,
     webrender_document: webrender_api::DocumentId,
     webgl_chan: Option<WebGLPipeline>,
@@ -545,6 +530,7 @@ impl UnprivilegedPipelineContent {
             self.script_chan.clone(),
             self.load_data.url.clone(),
         );
+        let (content_process_shutdown_chan, content_process_shutdown_port) = unbounded();
         let layout_thread_busy_flag = Arc::new(AtomicBool::new(false));
         let layout_pair = STF::create(
             InitialScriptState {
@@ -567,7 +553,7 @@ impl UnprivilegedPipelineContent {
                 devtools_chan: self.devtools_chan,
                 window_size: self.window_size,
                 pipeline_namespace_id: self.pipeline_namespace_id,
-                content_process_shutdown_chan: self.script_content_process_shutdown_chan,
+                content_process_shutdown_chan: content_process_shutdown_chan,
                 webgl_chan: self.webgl_chan,
                 webvr_chan: self.webvr_chan,
                 webxr_registry: self.webxr_registry,
@@ -605,7 +591,6 @@ impl UnprivilegedPipelineContent {
             self.font_cache_thread,
             self.time_profiler_chan,
             self.mem_profiler_chan,
-            Some(self.layout_content_process_shutdown_chan),
             self.webrender_api_sender,
             self.webrender_document,
             paint_time_metrics,
@@ -624,8 +609,10 @@ impl UnprivilegedPipelineContent {
         );
 
         if wait_for_completion {
-            let _ = self.script_content_process_shutdown_port.recv();
-            let _ = self.layout_content_process_shutdown_port.recv();
+            match content_process_shutdown_port.recv() {
+                Ok(()) => {},
+                Err(_) => error!("Script-thread shut-down unexpectedly"),
+            }
         }
     }
 

components/layout_thread/lib.rs

@@ -306,7 +306,6 @@ impl LayoutThreadFactory for LayoutThread {
         font_cache_thread: FontCacheThread,
         time_profiler_chan: profile_time::ProfilerChan,
         mem_profiler_chan: profile_mem::ProfilerChan,
-        content_process_shutdown_chan: Option<IpcSender<()>>,
         webrender_api_sender: webrender_api::RenderApiSender,
         webrender_document: webrender_api::DocumentId,
         paint_time_metrics: PaintTimeMetrics,
@@ -383,9 +382,6 @@ impl LayoutThreadFactory for LayoutThread {
                         Msg::CollectReports,
                     );
                 }
-                if let Some(content_process_shutdown_chan) = content_process_shutdown_chan {
-                    let _ = content_process_shutdown_chan.send(());
-                }
             })
             .expect("Thread spawning failed");
     }
@@ -951,7 +947,6 @@ impl LayoutThread {
             self.font_cache_thread.clone(),
             self.time_profiler_chan.clone(),
             self.mem_profiler_chan.clone(),
-            info.content_process_shutdown_chan,
             self.webrender_api.clone_sender(),
             self.webrender_document,
             info.paint_time_metrics,

components/layout_thread_2020/lib.rs

@@ -243,7 +243,6 @@ impl LayoutThreadFactory for LayoutThread {
         font_cache_thread: FontCacheThread,
         time_profiler_chan: profile_time::ProfilerChan,
         mem_profiler_chan: profile_mem::ProfilerChan,
-        content_process_shutdown_chan: Option<IpcSender<()>>,
         webrender_api_sender: webrender_api::RenderApiSender,
         webrender_document: webrender_api::DocumentId,
         paint_time_metrics: PaintTimeMetrics,
@@ -312,9 +311,6 @@ impl LayoutThreadFactory for LayoutThread {
                         Msg::CollectReports,
                     );
                 }
-                if let Some(content_process_shutdown_chan) = content_process_shutdown_chan {
-                    let _ = content_process_shutdown_chan.send(());
-                }
             })
             .expect("Thread spawning failed");
     }
@@ -819,7 +815,6 @@ impl LayoutThread {
             self.font_cache_thread.clone(),
             self.time_profiler_chan.clone(),
             self.mem_profiler_chan.clone(),
-            info.content_process_shutdown_chan,
             self.webrender_api.clone_sender(),
             self.webrender_document,
             info.paint_time_metrics,

components/layout_traits/lib.rs

@@ -43,7 +43,6 @@ pub trait LayoutThreadFactory {
         font_cache_thread: FontCacheThread,
         time_profiler_chan: time::ProfilerChan,
         mem_profiler_chan: mem::ProfilerChan,
-        content_process_shutdown_chan: Option<IpcSender<()>>,
         webrender_api_sender: webrender_api::RenderApiSender,
         webrender_document: webrender_api::DocumentId,
         paint_time_metrics: PaintTimeMetrics,

components/script/dom/htmliframeelement.rs

@@ -198,7 +198,6 @@ impl HTMLIFrameElement {
                     opener: None,
                     load_data: load_data,
                     pipeline_port: pipeline_receiver,
-                    content_process_shutdown_chan: None,
                     window_size: WindowSizeData {
                         initial_viewport: {
                             let rect = self.upcast::<Node>().bounding_content_box_or_zero();

components/script/dom/windowproxy.rs

@@ -303,7 +303,6 @@ impl WindowProxy {
                 opener: Some(self.browsing_context_id),
                 load_data: load_data,
                 pipeline_port: pipeline_receiver,
-                content_process_shutdown_chan: None,
                 window_size: window.window_size(),
             };
             let constellation_msg = ScriptMsg::ScriptNewAuxiliary(load_info, pipeline_sender);

components/script/script_thread.rs

@@ -612,7 +612,7 @@ pub struct ScriptThread {
     timer_event_chan: Sender<TimerEvent>,
     timer_event_port: Receiver<TimerEvent>,
 
-    content_process_shutdown_chan: IpcSender<()>,
+    content_process_shutdown_chan: Sender<()>,
 
     /// <https://html.spec.whatwg.org/multipage/#microtask-queue>
     microtask_queue: Rc<MicrotaskQueue>,
@@ -2276,7 +2276,6 @@ impl ScriptThread {
             load_data,
             window_size,
             pipeline_port,
-            content_process_shutdown_chan,
         } = new_layout_info;
 
         let layout_pair = unbounded();
@@ -2294,7 +2293,6 @@ impl ScriptThread {
             constellation_chan: self.layout_to_constellation_chan.clone(),
             script_chan: self.control_chan.clone(),
             image_cache: self.image_cache.clone(),
-            content_process_shutdown_chan: content_process_shutdown_chan,
             paint_time_metrics: PaintTimeMetrics::new(
                 new_pipeline_id,
                 self.time_profiler_chan.clone(),

components/script_layout_interface/message.rs

@@ -225,7 +225,6 @@ pub struct LayoutThreadInit {
     pub constellation_chan: IpcSender<ConstellationMsg>,
     pub script_chan: IpcSender<ConstellationControlMsg>,
     pub image_cache: Arc<dyn ImageCache>,
-    pub content_process_shutdown_chan: Option<IpcSender<()>>,
     pub paint_time_metrics: PaintTimeMetrics,
     pub layout_is_busy: Arc<AtomicBool>,
 }

components/script_traits/lib.rs

@@ -219,8 +219,6 @@ pub struct NewLayoutInfo {
     pub window_size: WindowSizeData,
     /// A port on which layout can receive messages from the pipeline.
     pub pipeline_port: IpcReceiver<LayoutControlMsg>,
-    /// A shutdown channel so that layout can tell the content process to shut down when it's done.
-    pub content_process_shutdown_chan: Option<IpcSender<()>>,
 }
 
 /// When a pipeline is closed, should its browsing context be discarded too?
@@ -651,7 +649,7 @@ pub struct InitialScriptState {
     /// The ID of the pipeline namespace for this script thread.
     pub pipeline_namespace_id: PipelineNamespaceId,
     /// A ping will be sent on this channel once the script thread shuts down.
-    pub content_process_shutdown_chan: IpcSender<()>,
+    pub content_process_shutdown_chan: Sender<()>,
     /// A channel to the WebGL thread used in this pipeline.
     pub webgl_chan: Option<WebGLPipeline>,
     /// A channel to the webvr thread, if available.