name : base-page-handle.h // Copyright 2022 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_CPPGC_INTERNAL_BASE_PAGE_HANDLE_H_ #define INCLUDE_CPPGC_INTERNAL_BASE_PAGE_HANDLE_H_ #include "cppgc/heap-handle.h" #include "cppgc/internal/api-constants.h" #include "cppgc/internal/logging.h" #include "v8config.h" // NOLINT(build/include_directory) namespace cppgc { namespace internal { // The class is needed in the header to allow for fast access to HeapHandle in // the write barrier. class BasePageHandle { public: static V8_INLINE BasePageHandle* FromPayload(void* payload) { return reinterpret_cast<BasePageHandle*>( (reinterpret_cast<uintptr_t>(payload) & ~(api_constants::kPageSize - 1)) + api_constants::kGuardPageSize); } static V8_INLINE const BasePageHandle* FromPayload(const void* payload) { return FromPayload(const_cast<void*>(payload)); } HeapHandle& heap_handle() { return heap_handle_; } const HeapHandle& heap_handle() const { return heap_handle_; } protected: explicit BasePageHandle(HeapHandle& heap_handle) : heap_handle_(heap_handle) { CPPGC_DCHECK(reinterpret_cast<uintptr_t>(this) % api_constants::kPageSize == api_constants::kGuardPageSize); } HeapHandle& heap_handle_; }; } // namespace internal } // namespace cppgc #endif // INCLUDE_CPPGC_INTERNAL_BASE_PAGE_HANDLE_H_