v8/src/context-measure.cc
yangguo 735fa0c478 [serializer] prepare attached references for general use.
Currently attached references are only used for global proxy, source
string and code stubs. Mid-term future we want to use attached
references for arbitrary objects (in fixed order) provided from outside.

This change renames BackReference to SerializerReference to include both
back references and attached references.

R=mtrofin@chromium.org, vogelheim@chromium.org

Review-Url: https://codereview.chromium.org/1992723002
Cr-Commit-Position: refs/heads/master@{#36318}
2016-05-18 11:30:33 +00:00

79 lines
2.1 KiB
C++

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/context-measure.h"
#include "src/base/logging.h"
#include "src/contexts.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
ContextMeasure::ContextMeasure(Context* context)
: context_(context),
root_index_map_(context->GetIsolate()),
recursion_depth_(0),
count_(0),
size_(0) {
DCHECK(context_->IsNativeContext());
Object* next_link = context_->next_context_link();
MeasureObject(context_);
MeasureDeferredObjects();
context_->set(Context::NEXT_CONTEXT_LINK, next_link);
}
bool ContextMeasure::IsShared(HeapObject* object) {
if (object->IsScript()) return true;
if (object->IsSharedFunctionInfo()) return true;
if (object->IsScopeInfo()) return true;
if (object->IsCode() && !Code::cast(object)->is_optimized_code()) return true;
if (object->IsAccessorInfo()) return true;
if (object->IsWeakCell()) return true;
return false;
}
void ContextMeasure::MeasureObject(HeapObject* object) {
if (reference_map_.Lookup(object).is_valid()) return;
if (root_index_map_.Lookup(object) != RootIndexMap::kInvalidRootIndex) return;
if (IsShared(object)) return;
reference_map_.Add(object, SerializerReference::DummyReference());
recursion_depth_++;
if (recursion_depth_ > kMaxRecursion) {
deferred_objects_.Add(object);
} else {
MeasureAndRecurse(object);
}
recursion_depth_--;
}
void ContextMeasure::MeasureDeferredObjects() {
while (deferred_objects_.length() > 0) {
MeasureAndRecurse(deferred_objects_.RemoveLast());
}
}
void ContextMeasure::MeasureAndRecurse(HeapObject* object) {
int size = object->Size();
count_++;
size_ += size;
Map* map = object->map();
MeasureObject(map);
object->IterateBody(map->instance_type(), size, this);
}
void ContextMeasure::VisitPointers(Object** start, Object** end) {
for (Object** current = start; current < end; current++) {
if ((*current)->IsSmi()) continue;
MeasureObject(HeapObject::cast(*current));
}
}
} // namespace internal
} // namespace v8