| // Copyright 2020 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 INCLUDE_V8_CPPGC_H_ |
| #define INCLUDE_V8_CPPGC_H_ |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "cppgc/custom-space.h" |
| #include "cppgc/internal/write-barrier.h" |
| #include "cppgc/visitor.h" |
| #include "v8-internal.h" // NOLINT(build/include_directory) |
| #include "v8.h" // NOLINT(build/include_directory) |
| |
| namespace cppgc { |
| class AllocationHandle; |
| class HeapHandle; |
| } // namespace cppgc |
| |
| namespace v8 { |
| |
| namespace internal { |
| class CppHeap; |
| } // namespace internal |
| |
| struct V8_EXPORT CppHeapCreateParams { |
| std::vector<std::unique_ptr<cppgc::CustomSpaceBase>> custom_spaces; |
| }; |
| |
| /** |
| * A heap for allocating managed C++ objects. |
| */ |
| class V8_EXPORT CppHeap { |
| public: |
| virtual ~CppHeap() = default; |
| |
| /** |
| * \returns the opaque handle for allocating objects using |
| * `MakeGarbageCollected()`. |
| */ |
| cppgc::AllocationHandle& GetAllocationHandle(); |
| |
| /** |
| * \returns the opaque heap handle which may be used to refer to this heap in |
| * other APIs. Valid as long as the underlying `CppHeap` is alive. |
| */ |
| cppgc::HeapHandle& GetHeapHandle(); |
| |
| private: |
| CppHeap() = default; |
| |
| friend class internal::CppHeap; |
| }; |
| |
| class JSVisitor : public cppgc::Visitor { |
| public: |
| explicit JSVisitor(cppgc::Visitor::Key key) : cppgc::Visitor(key) {} |
| |
| void Trace(const TracedReferenceBase& ref) { |
| if (ref.IsEmptyThreadSafe()) return; |
| Visit(ref); |
| } |
| |
| protected: |
| using cppgc::Visitor::Visit; |
| |
| virtual void Visit(const TracedReferenceBase& ref) {} |
| }; |
| |
| /** |
| * **DO NOT USE: Use the appropriate managed types.** |
| * |
| * Consistency helpers that aid in maintaining a consistent internal state of |
| * the garbage collector. |
| */ |
| class JSHeapConsistency final { |
| public: |
| using WriteBarrierParams = cppgc::internal::WriteBarrier::Params; |
| using WriteBarrierType = cppgc::internal::WriteBarrier::Type; |
| |
| /** |
| * Gets the required write barrier type for a specific write. |
| * |
| * \param ref The reference being written to. |
| * \param params Parameters that may be used for actual write barrier calls. |
| * Only filled if return value indicates that a write barrier is needed. The |
| * contents of the `params` are an implementation detail. |
| * \returns whether a write barrier is needed and which barrier to invoke. |
| */ |
| static V8_INLINE WriteBarrierType GetWriteBarrierType( |
| const TracedReferenceBase& ref, WriteBarrierParams& params) { |
| if (ref.IsEmpty()) return WriteBarrierType::kNone; |
| return cppgc::internal::WriteBarrier::GetWriteBarrierType(&ref, params); |
| } |
| |
| /** |
| * Conservative Dijkstra-style write barrier that processes an object if it |
| * has not yet been processed. |
| * |
| * \param params The parameters retrieved from `GetWriteBarrierType()`. |
| * \param ref The reference being written to. |
| */ |
| static V8_INLINE void DijkstraMarkingBarrier(const WriteBarrierParams& params, |
| cppgc::HeapHandle& heap_handle, |
| const TracedReferenceBase& ref) { |
| cppgc::internal::WriteBarrier::CheckParams(WriteBarrierType::kMarking, |
| params); |
| DijkstraMarkingBarrierSlow(heap_handle, ref); |
| } |
| |
| /** |
| * Generational barrier for maintaining consistency when running with multiple |
| * generations. |
| * |
| * \param params The parameters retrieved from `GetWriteBarrierType()`. |
| * \param ref The reference being written to. |
| */ |
| static V8_INLINE void GenerationalBarrier(const WriteBarrierParams& params, |
| const TracedReferenceBase& ref) {} |
| |
| private: |
| JSHeapConsistency() = delete; |
| |
| static void DijkstraMarkingBarrierSlow(cppgc::HeapHandle&, |
| const TracedReferenceBase& ref); |
| }; |
| |
| } // namespace v8 |
| |
| namespace cppgc { |
| |
| template <typename T> |
| struct TraceTrait<v8::TracedReference<T>> { |
| static void Trace(Visitor* visitor, const v8::TracedReference<T>* self) { |
| static_cast<v8::JSVisitor*>(visitor)->Trace(*self); |
| } |
| }; |
| |
| } // namespace cppgc |
| |
| #endif // INCLUDE_V8_CPPGC_H_ |