Auto merge of #6334 - nnethercote:report-local-contexts, r=pcwalton

Passing a function that measures TLS to WorkQueue is a bit weird, but I can't see how else to measure that data.

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components/layout/context.rs

@@ -29,6 +29,7 @@ use std::sync::mpsc::{channel, Sender};
 use style::selector_matching::Stylist;
 use url::Url;
 use util::geometry::Au;
+use util::mem::HeapSizeOf;
 use util::opts;
 
 struct LocalLayoutContext {
@@ -37,8 +38,21 @@ struct LocalLayoutContext {
     style_sharing_candidate_cache: RefCell<StyleSharingCandidateCache>,
 }
 
+impl HeapSizeOf for LocalLayoutContext {
+    // FIXME(njn): measure other fields eventually.
+    fn heap_size_of_children(&self) -> usize {
+        self.font_context.heap_size_of_children()
+    }
+}
+
 thread_local!(static LOCAL_CONTEXT_KEY: RefCell<Option<Rc<LocalLayoutContext>>> = RefCell::new(None));
 
+pub fn heap_size_of_local_context() -> usize {
+    LOCAL_CONTEXT_KEY.with(|r| {
+        r.borrow().clone().map_or(0, |context| context.heap_size_of_children())
+    })
+}
+
 fn create_or_get_local_context(shared_layout_context: &SharedLayoutContext)
                                -> Rc<LocalLayoutContext> {
     LOCAL_CONTEXT_KEY.with(|r| {

components/layout/layout_task.rs

@@ -9,7 +9,7 @@
 
 use animation;
 use construct::ConstructionResult;
-use context::{SharedLayoutContext, SharedLayoutContextWrapper};
+use context::{SharedLayoutContext, SharedLayoutContextWrapper, heap_size_of_local_context};
 use css::node_style::StyledNode;
 use data::{LayoutDataAccess, LayoutDataWrapper};
 use display_list_builder::ToGfxColor;
@@ -575,10 +575,28 @@ impl LayoutTask {
         let rw_data = self.lock_rw_data(possibly_locked_rw_data);
         let stacking_context = rw_data.stacking_context.as_ref();
         reports.push(Report {
-            path: path!["pages", format!("url({})", self.url), "display-list"],
+            path: path!["pages", format!("url({})", self.url), "layout-task", "display-list"],
             size: stacking_context.map_or(0, |sc| sc.heap_size_of_children()),
         });
 
+        // The LayoutTask has a context in TLS...
+        reports.push(Report {
+            path: path!["pages", format!("url({})", self.url), "layout-task", "local-context"],
+            size: heap_size_of_local_context(),
+        });
+
+        // ... as do each of the LayoutWorkers, if present.
+        if let Some(ref traversal) = rw_data.parallel_traversal {
+            let sizes = traversal.heap_size_of_tls(heap_size_of_local_context);
+            for (i, size) in sizes.iter().enumerate() {
+                reports.push(Report {
+                    path: path!["pages", format!("url({})", self.url),
+                                format!("layout-worker-{}-local-context", i)],
+                    size: *size
+                });
+            }
+        }
+
         reports_chan.send(reports);
     }