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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=2 sw=2 et tw=78:
* 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/.
*/
#ifndef nsPresArena_h___
#define nsPresArena_h___
#include "nscore.h"
#include "nsQueryFrame.h"
#include "mozilla/StandardInteger.h"
struct nsArenaMemoryStats;
// Uncomment this to disable arenas, instead forwarding to
// malloc for every allocation.
//#define DEBUG_TRACEMALLOC_PRESARENA 1
// The debugging version of nsPresArena does not free all the memory it
// allocated when the arena itself is destroyed.
#ifdef DEBUG_TRACEMALLOC_PRESARENA
#define PRESARENA_MUST_FREE_DURING_DESTROY true
#else
#define PRESARENA_MUST_FREE_DURING_DESTROY false
#endif
class nsPresArena {
public:
nsPresArena();
~nsPresArena();
// Pool allocation with recycler lists indexed by object size, aSize.
NS_HIDDEN_(void*) AllocateBySize(size_t aSize);
NS_HIDDEN_(void) FreeBySize(size_t aSize, void* aPtr);
// Pool allocation with recycler lists indexed by frame-type ID.
// Every aID must always be used with the same object size, aSize.
NS_HIDDEN_(void*) AllocateByFrameID(nsQueryFrame::FrameIID aID, size_t aSize);
NS_HIDDEN_(void) FreeByFrameID(nsQueryFrame::FrameIID aID, void* aPtr);
enum ObjectID {
nsLineBox_id = nsQueryFrame::NON_FRAME_MARKER,
nsRuleNode_id,
nsStyleContext_id,
// The PresArena implementation uses this bit to distinguish objects
// allocated by size from objects allocated by type ID (that is, frames
// using AllocateByFrameID and other objects using AllocateByObjectID).
// It should not collide with any Object ID (above) or frame ID (in
// nsQueryFrame.h). It is not 0x80000000 to avoid the question of
// whether enumeration constants are signed.
NON_OBJECT_MARKER = 0x40000000
};
// Pool allocation with recycler lists indexed by object-type ID (see above).
// Every aID must always be used with the same object size, aSize.
NS_HIDDEN_(void*) AllocateByObjectID(ObjectID aID, size_t aSize);
NS_HIDDEN_(void) FreeByObjectID(ObjectID aID, void* aPtr);
/**
* Fill aArenaStats with sizes of interesting objects allocated in
* this arena and its mOther field with the size of everything else.
*/
void SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf,
nsArenaMemoryStats* aArenaStats);
/**
* Get the poison value that can be used to fill a memory space with
* an address that leads to a safe crash when dereferenced.
*
* The caller is responsible for ensuring that a pres shell has been
* initialized before calling this.
*/
static uintptr_t GetPoisonValue();
private:
struct State;
State* mState;
};
#endif
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