// 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 V8_HEAP_CPPGC_VIRTUAL_MEMORY_H_ #define V8_HEAP_CPPGC_VIRTUAL_MEMORY_H_ #include <cstdint> #include "include/cppgc/platform.h" #include "src/base/macros.h" namespace cppgc { namespace internal { // Represents and controls an area of reserved memory. class V8_EXPORT_PRIVATE VirtualMemory { public: // Empty VirtualMemory object, controlling no reserved memory. VirtualMemory() = default; // Reserves virtual memory containing an area of the given size that is // aligned per |alignment| rounded up to the |page_allocator|'s allocate page // size. The |size| is aligned with |page_allocator|'s commit page size. VirtualMemory(PageAllocator*, size_t size, size_t alignment, void* hint = nullptr); // Releases the reserved memory, if any, controlled by this VirtualMemory // object. ~VirtualMemory() V8_NOEXCEPT; VirtualMemory(VirtualMemory&&) V8_NOEXCEPT; VirtualMemory& operator=(VirtualMemory&&) V8_NOEXCEPT; // Returns whether the memory has been reserved. bool IsReserved() const { return start_ != nullptr; } void* address() const { DCHECK(IsReserved()); return start_; } size_t size() const { DCHECK(IsReserved()); return size_; } private: // Resets to the default state. void Reset(); PageAllocator* page_allocator_ = nullptr; void* start_ = nullptr; size_t size_ = 0; }; } // namespace internal } // namespace cppgc #endif // V8_HEAP_CPPGC_VIRTUAL_MEMORY_H_