Auto merge of #19994 - Manishearth:rm-telemetry, r=upsuper

Remove traversal telemetry

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components/style/driver.rs

@@ -7,7 +7,7 @@
 
 #![deny(missing_docs)]
 
-use context::{StyleContext, ThreadLocalStyleContext, TraversalStatistics};
+use context::{StyleContext, ThreadLocalStyleContext};
 use dom::{SendNode, TElement, TNode};
 use parallel;
 use parallel::{DispatchMode, WORK_UNIT_MAX};
@@ -33,7 +33,7 @@ pub fn traverse_dom<E, D>(
     traversal: &D,
     token: PreTraverseToken<E>,
     pool: Option<&rayon::ThreadPool>
-) -> (bool, Option<TraversalStatistics>)
+)
 where
     E: TElement,
     D: DomTraversal<E>,
@@ -43,7 +43,6 @@ where
 
     let dump_stats = traversal.shared_context().options.dump_style_statistics;
     let is_nightly  = traversal.shared_context().options.is_nightly();
-    let mut used_parallel = false;
     let start_time = if dump_stats { Some(time::precise_time_s()) } else { None };
 
     // Declare the main-thread context, as well as the worker-thread contexts,
@@ -90,7 +89,6 @@ where
             // moving to the next level in the dom so that we can pass the same
             // depth for all the children.
             if pool.is_some() && discovered.len() > WORK_UNIT_MAX {
-                used_parallel = true;
                 let pool = pool.unwrap();
                 maybe_tls = Some(ScopedTLS::<ThreadLocalStyleContext<E>>::new(pool));
                 let root_opaque = root.as_node().opaque();
@@ -115,7 +113,6 @@ where
             nodes_remaining_at_current_depth = discovered.len();
         }
     }
-    let mut maybe_stats = None;
     // Accumulate statistics
     if dump_stats || is_nightly {
         let mut aggregate =
@@ -136,8 +133,5 @@ where
             aggregate.finish(traversal, parallel, start_time.unwrap());
              println!("{}", aggregate);
         }
-        maybe_stats = Some(aggregate);
     }
-
-    (used_parallel, maybe_stats)
 }

components/style/gecko/data.rs

@@ -5,7 +5,6 @@
 //! Data needed to style a Gecko document.
 
 use atomic_refcell::{AtomicRef, AtomicRefCell, AtomicRefMut};
-use context::TraversalStatistics;
 use dom::TElement;
 use gecko_bindings::bindings::{self, RawServoStyleSet};
 use gecko_bindings::structs::{RawGeckoPresContextOwned, ServoStyleSetSizes, ServoStyleSheet};
@@ -18,7 +17,6 @@ use properties::ComputedValues;
 use selector_parser::SnapshotMap;
 use servo_arc::Arc;
 use shared_lock::{Locked, StylesheetGuards, SharedRwLockReadGuard};
-use std::sync::atomic::{AtomicUsize, Ordering};
 use stylesheets::{StylesheetContents, StylesheetInDocument};
 use stylist::Stylist;
 
@@ -110,40 +108,11 @@ impl StylesheetInDocument for GeckoStyleSheet {
     }
 }
 
-#[derive(Default)]
-/// Helper struct for counting traversals
-pub struct TraversalCount {
-    /// Total number of events
-    pub total_count: AtomicUsize,
-    /// Number of events which were parallel
-    pub parallel_count: AtomicUsize
-}
-
-impl TraversalCount {
-    fn record(&self, parallel: bool, count: u32) {
-        self.total_count.fetch_add(count as usize, Ordering::Relaxed);
-        if parallel {
-            self.parallel_count.fetch_add(count as usize, Ordering::Relaxed);
-        }
-    }
-
-    fn get(&self) -> (u32, u32) {
-        (self.total_count.load(Ordering::Relaxed) as u32,
-         self.parallel_count.load(Ordering::Relaxed) as u32)
-    }
-}
-
 /// The container for data that a Servo-backed Gecko document needs to style
 /// itself.
 pub struct PerDocumentStyleDataImpl {
     /// Rule processor.
     pub stylist: Stylist,
-    /// Counter for traversals that could have been parallel, for telemetry
-    pub traversal_count: TraversalCount,
-    /// Counter for traversals, weighted by elements traversed,
-    pub traversal_count_traversed: TraversalCount,
-    /// Counter for traversals, weighted by elements styled,
-    pub traversal_count_styled: TraversalCount,
 }
 
 /// The data itself is an `AtomicRefCell`, which guarantees the proper semantics
@@ -165,9 +134,6 @@ impl PerDocumentStyleData {
 
         PerDocumentStyleData(AtomicRefCell::new(PerDocumentStyleDataImpl {
             stylist: Stylist::new(device, quirks_mode.into()),
-            traversal_count: Default::default(),
-            traversal_count_traversed: Default::default(),
-            traversal_count_styled: Default::default(),
         }))
     }
 
@@ -187,13 +153,6 @@ impl Drop for PerDocumentStyleDataImpl {
         if !structs::GECKO_IS_NIGHTLY {
             return
         }
-        let (total, parallel)  = self.traversal_count.get();
-        let (total_t, parallel_t)  = self.traversal_count_traversed.get();
-        let (total_s, parallel_s)  = self.traversal_count_styled.get();
-
-        unsafe { bindings::Gecko_RecordTraversalStatistics(total, parallel,
-                                                           total_t, parallel_t,
-                                                           total_s, parallel_s) }
     }
 }
 
@@ -261,15 +220,6 @@ impl PerDocumentStyleDataImpl {
     pub fn add_size_of(&self, ops: &mut MallocSizeOfOps, sizes: &mut ServoStyleSetSizes) {
         self.stylist.add_size_of(ops, sizes);
     }
-
-    /// Record that a traversal happened for later collection as telemetry
-    pub fn record_traversal(&self, was_parallel: bool, stats: Option<TraversalStatistics>) {
-        self.traversal_count.record(was_parallel, 1);
-        if let Some(stats) = stats {
-            self.traversal_count_traversed.record(was_parallel, stats.elements_traversed);
-            self.traversal_count_styled.record(was_parallel, stats.elements_styled);
-        }
-    }
 }
 
 unsafe impl HasFFI for PerDocumentStyleData {

components/style/gecko/generated/bindings.rs

@@ -546,16 +546,6 @@ extern "C" {
 extern "C" {
     pub fn Servo_SourceSizeList_Drop(ptr: RawServoSourceSizeListOwned);
 }
-extern "C" {
-    pub fn Gecko_RecordTraversalStatistics(
-        total: u32,
-        parallel: u32,
-        total_t: u32,
-        parallel_t: u32,
-        total_s: u32,
-        parallel_s: u32,
-    );
-}
 extern "C" {
     pub fn Gecko_IsSignificantChild(
         node: RawGeckoNodeBorrowed,

ports/geckolib/glue.rs

@@ -279,19 +279,8 @@ fn traverse_subtree(
         None
     };
 
-    let is_restyle = element.get_data().is_some();
-
     let traversal = RecalcStyleOnly::new(shared_style_context);
-    let (used_parallel, stats) = driver::traverse_dom(&traversal, token, thread_pool);
+    driver::traverse_dom(&traversal, token, thread_pool);
-
-    if traversal_flags.contains(TraversalFlags::ParallelTraversal) &&
-       !traversal_flags.contains(TraversalFlags::AnimationOnly) &&
-       is_restyle && !element.is_native_anonymous() {
-       // We turn off parallel traversal for background tabs; this
-       // shouldn't count in telemetry. We're also focusing on restyles so
-       // we ensure that it's a restyle.
-       per_doc_data.record_traversal(used_parallel, stats);
-    }
 }
 
 /// Traverses the subtree rooted at `root` for restyling.