chromium/third_party/angle/src/common/PoolAlloc.h

//
// Copyright 2019 The ANGLE 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.
//
// PoolAlloc.h:
//    Defines the class interface for PoolAllocator.
//

#ifndef COMMON_POOLALLOC_H_
#define COMMON_POOLALLOC_H_

#if !defined(NDEBUG)
#define ANGLE_POOL_ALLOC_GUARD_BLOCKS …
#endif

//
// This header defines an allocator that can be used to efficiently
// allocate a large number of small requests for heap memory, with the
// intention that they are not individually deallocated, but rather
// collectively deallocated at one time.
//
// This simultaneously
//
// * Makes each individual allocation much more efficient; the
//     typical allocation is trivial.
// * Completely avoids the cost of doing individual deallocation.
// * Saves the trouble of tracking down and plugging a large class of leaks.
//
// Individual classes can use this allocator by supplying their own
// new and delete methods.
//

#include "angleutils.h"
#include "common/debug.h"

namespace angle
{
class Allocation;
class PageHeader;

//
// There are several stacks.  One is to track the pushing and popping
// of the user, and not yet implemented.  The others are simply a
// repositories of free pages or used pages.
//
// Page stacks are linked together with a simple header at the beginning
// of each allocation obtained from the underlying OS.  Multi-page allocations
// are returned to the OS.  Individual page allocations are kept for future
// re-use.
//
// The "page size" used is not, nor must it match, the underlying OS
// page size.  But, having it be about that size or equal to a set of
// pages is likely most optimal.
//
class PoolAllocator : angle::NonCopyable
{ … };

}  // namespace angle

#endif  // COMMON_POOLALLOC_H_