chromium/v8/src/base/bounded-page-allocator.h

// Copyright 2018 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_BASE_BOUNDED_PAGE_ALLOCATOR_H_
#define V8_BASE_BOUNDED_PAGE_ALLOCATOR_H_

#include "include/v8-platform.h"
#include "src/base/platform/mutex.h"
#include "src/base/region-allocator.h"

namespace v8 {
namespace base {

// Defines the page initialization mode of a BoundedPageAllocator.
enum class PageInitializationMode { … };

// Defines how BoundedPageAllocator frees pages when FreePages or ReleasePages
// is requested.
enum class PageFreeingMode { … };

// This is a v8::PageAllocator implementation that allocates pages within the
// pre-reserved region of virtual space. This class requires the virtual space
// to be kept reserved during the lifetime of this object.
// The main application of bounded page allocator are
//  - V8 heap pointer compression which requires the whole V8 heap to be
//    allocated within a contiguous range of virtual address space,
//  - executable page allocation, which allows to use PC-relative 32-bit code
//    displacement on certain 64-bit platforms.
// Bounded page allocator uses other page allocator instance for doing actual
// page allocations.
// The implementation is thread-safe.
class V8_BASE_EXPORT BoundedPageAllocator : public v8::PageAllocator { … };

}  // namespace base
}  // namespace v8

#endif  // V8_BASE_BOUNDED_PAGE_ALLOCATOR_H_