gecko-dev/layout/base/nsPresArena.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* arena allocation for the frame tree and closely-related objects */
#ifndef nsPresArena_h___
#define nsPresArena_h___
#include "mozilla/ArenaAllocator.h"
#include "mozilla/ArenaObjectID.h"
#include "mozilla/Assertions.h"
#include "mozilla/MemoryChecking.h" // Note: Do not remove this, needed for MOZ_HAVE_MEM_CHECKS below
#include "mozilla/MemoryReporting.h"
#include <stdint.h>
#include "nscore.h"
#include "nsHashKeys.h"
#include "nsTArray.h"
#include "nsTHashtable.h"
class nsWindowSizes;
template <size_t ArenaSize, typename ObjectId, size_t ObjectIdCount>
class nsPresArena {
public:
nsPresArena() = default;
~nsPresArena();
/**
* Pool allocation with recycler lists indexed by object-type ID (see above).
* Every aID must always be used with the same object size, aSize.
*/
void* Allocate(ObjectId aCode, size_t aSize);
void Free(ObjectId aCode, void* aPtr);
enum class ArenaKind { PresShell, DisplayList };
/**
* Increment nsWindowSizes with sizes of interesting objects allocated in this
* arena, and put the general unclassified size in the relevant field
* depending on the arena size.
*/
void AddSizeOfExcludingThis(nsWindowSizes&, ArenaKind) const;
void Check() { mPool.Check(); }
private:
class FreeList {
public:
nsTArray<void*> mEntries;
size_t mEntrySize;
size_t mEntriesEverAllocated;
FreeList() : mEntrySize(0), mEntriesEverAllocated(0) {}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
return mEntries.ShallowSizeOfExcludingThis(aMallocSizeOf);
}
};
FreeList mFreeLists[ObjectIdCount];
mozilla::ArenaAllocator<ArenaSize, 8> mPool;
};
#endif