Implement frame attribution (FrameBlamer)

third_party/WebKit/Source/bindings/core/v8/V8GCController.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 33 matching lines @@
 #include "core/dom/TemplateContentDocumentFragment.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/imports/HTMLImportsController.h"
 #include "core/inspector/InspectorTraceEvents.h"
 #include "core/svg/SVGElement.h"
 #include "platform/Histogram.h"
 #include "platform/TraceEvent.h"
+#include "public/platform/WebBlameContext.h"
 #include "wtf/Partitions.h"
 #include "wtf/Vector.h"
 #include <algorithm>
 
 namespace blink {
 
 // FIXME: This should use opaque GC roots.
 static void addReferencesForNodeWithEventListeners(v8::Isolate* isolate, Node* node, const v8::Persistent<v8::Object>& wrapper)
 {
     ASSERT(node->hasEventListeners());
@@ skipping 204 matching lines @@
 
 void gcPrologueForMajorGC(v8::Isolate* isolate, bool constructRetainedObjectInfos)
 {
     objectGroupingForMajorGC(isolate, constructRetainedObjectInfos);
 }
 
 } // namespace
 
 void V8GCController::gcPrologue(v8::Isolate* isolate, v8::GCType type, v8::GCCallbackFlags flags)
 {
-    if (isMainThread())
+    if (isMainThread()) {
         ScriptForbiddenScope::enter();
+        // Attribute garbage collection to the entire thread instead of a specific
+        // frame.
+    }
+
+    if (WebBlameContext* blame_context = Platform::current()->threadBlameContext())
+        blame_context->enter();
 
     // TODO(haraken): A GC callback is not allowed to re-enter V8. This means
     // that it's unsafe to run Oilpan's GC in the GC callback because it may
     // run finalizers that call into V8. To avoid the risk, we should post
     // a task to schedule the Oilpan's GC.
     // (In practice, there is no finalizer that calls into V8 and thus is safe.)
 
-    v8::HandleScope scope(isolate);
     switch (type) {
     case v8::kGCTypeScavenge:
         if (ThreadState::current())
             ThreadState::current()->willStartV8GC(BlinkGC::V8MinorGC);
 
         TRACE_EVENT_BEGIN1("devtools.timeline,v8", "MinorGC", "usedHeapSizeBefore", usedHeapSize(isolate));
         visitWeakHandlesForMinorGC(isolate);
         break;
     case v8::kGCTypeMarkSweepCompact:
         if (ThreadState::current())
@@ skipping 34 matching lines @@
     case v8::kGCTypeIncrementalMarking:
         TRACE_EVENT_END1("devtools.timeline,v8", "MajorGC", "usedHeapSizeAfter", usedHeapSize(isolate));
         break;
     case v8::kGCTypeProcessWeakCallbacks:
         TRACE_EVENT_END1("devtools.timeline,v8", "MajorGC", "usedHeapSizeAfter", usedHeapSize(isolate));
         break;
     default:
         ASSERT_NOT_REACHED();
     }
 
-    if (isMainThread())
+    if (isMainThread()) {
         ScriptForbiddenScope::exit();
+    }
+
+    if (WebBlameContext* blame_context = Platform::current()->threadBlameContext())
+        blame_context->leave();
 
     // v8::kGCCallbackFlagForced forces a Blink heap garbage collection
     // when a garbage collection was forced from V8. This is either used
     // for tests that force GCs from JavaScript to verify that objects die
     // when expected, or when handling memory pressure notifications.
     if (flags & v8::kGCCallbackFlagForced) {
         // This single GC is not enough for two reasons:
         //   (1) The GC is not precise because the GC scans on-stack pointers conservatively.
         //   (2) One GC is not enough to break a chain of persistent handles. It's possible that
         //       some heap allocated objects own objects that contain persistent handles
@@ skipping 131 matching lines @@
 
     DEFINE_THREAD_SAFE_STATIC_LOCAL(CustomCountHistogram, scanPendingActivityHistogram, new CustomCountHistogram("Blink.ScanPendingActivityDuration", 1, 1000, 50));
     double startTime = WTF::currentTimeMS();
     PendingActivityVisitor visitor(executionContext);
     toIsolate(executionContext)->VisitHandlesWithClassIds(&visitor);
     scanPendingActivityHistogram.count(static_cast<int>(WTF::currentTimeMS() - startTime));
     return visitor.pendingActivityFound();
 }
 
 } // namespace blink