marking-visitor.h | Explore in Territory

// Copyright 2019 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.

#ifndef V8_HEAP_MARKING_VISITOR_H_
#define V8_HEAP_MARKING_VISITOR_H_

#include "src/base/logging.h"
#include "src/common/globals.h"
#include "src/execution/isolate.h"
#include "src/heap/marking-state.h"
#include "src/heap/marking-worklist.h"
#include "src/heap/marking.h"
#include "src/heap/objects-visiting.h"
#include "src/heap/pretenuring-handler.h"
#include "src/heap/spaces.h"
#include "src/heap/weak-object-worklists.h"

namespace v8 {
namespace internal {

struct EphemeronMarking { … };

// The base class for all marking visitors (main and concurrent marking) but
// also for e.g. the reference summarizer. It implements marking logic with
// support for bytecode flushing, embedder tracing and weak references.
//
// Derived classes are expected to provide the following methods:
// - CanUpdateValuesInHeap
// - AddStrongReferenceForReferenceSummarizer
// - AddWeakReferenceForReferenceSummarizer
// - marking_state
// - MarkPointerTableEntry
// - RecordSlot
// - RecordRelocSlot
//
// These methods capture the difference between the different visitor
// implementations. For example, the concurrent visitor has to use the locking
// for string types that can be transitioned to other types on the main thread
// concurrently. On the other hand, the reference summarizer is not supposed to
// write into heap objects.
template <typename ConcreteVisitor>
class MarkingVisitorBase : public ConcurrentHeapVisitor<int, ConcreteVisitor> { … };

// This is the common base class for main and concurrent full marking visitors.
// Derived class are expected to provide the same methods as for
// MarkingVisitorBase except for those defined in this class.
template <typename ConcreteVisitor>
class FullMarkingVisitorBase : public MarkingVisitorBase<ConcreteVisitor> { … };

}  // namespace internal
}  // namespace v8

#endif  // V8_HEAP_MARKING_VISITOR_H_
chromium/v8/src/heap/marking-visitor.h
