/* -*- 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/. */ /* arena allocation for the frame tree and closely-related objects */ #ifndef nsPresArena_h___ #define nsPresArena_h___ #include "mozilla/ArenaObjectID.h" #include "mozilla/ArenaRefPtr.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 "nsDataHashtable.h" #include "nsHashKeys.h" #include "nsTArray.h" #include "nsTHashtable.h" #include "plarena.h" struct nsArenaMemoryStats; class nsPresArena { public: nsPresArena(); ~nsPresArena(); /** * Pool allocation with recycler lists indexed by object size, aSize. */ void* AllocateBySize(size_t aSize) { return Allocate(uint32_t(aSize) | uint32_t(mozilla::eArenaObjectID_NON_OBJECT_MARKER), aSize); } void FreeBySize(size_t aSize, void* aPtr) { Free(uint32_t(aSize) | uint32_t(mozilla::eArenaObjectID_NON_OBJECT_MARKER), aPtr); } /** * Pool allocation with recycler lists indexed by frame-type ID. * Every aID must always be used with the same object size, aSize. */ void* AllocateByFrameID(nsQueryFrame::FrameIID aID, size_t aSize) { return Allocate(aID, aSize); } void FreeByFrameID(nsQueryFrame::FrameIID aID, void* aPtr) { Free(aID, aPtr); } /** * 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* AllocateByObjectID(mozilla::ArenaObjectID aID, size_t aSize) { return Allocate(aID, aSize); } void FreeByObjectID(mozilla::ArenaObjectID aID, void* aPtr) { Free(aID, aPtr); } /** * Register an ArenaRefPtr to be cleared when this arena is about to * be destroyed. * * (Defined in ArenaRefPtrInlines.h.) * * @param aPtr The ArenaRefPtr to clear. * @param aObjectID The ArenaObjectID value that uniquely identifies * the type of object the ArenaRefPtr holds. */ template<typename T> void RegisterArenaRefPtr(mozilla::ArenaRefPtr<T>* aPtr); /** * Deregister an ArenaRefPtr that was previously registered with * RegisterArenaRefPtr. */ template<typename T> void DeregisterArenaRefPtr(mozilla::ArenaRefPtr<T>* aPtr) { MOZ_ASSERT(mArenaRefPtrs.Contains(aPtr)); mArenaRefPtrs.Remove(aPtr); } /** * Clears all currently registered ArenaRefPtrs. This will be called during * the destructor, but can be called by users of nsPresArena who want to * ensure arena-allocated objects are released earlier. */ void ClearArenaRefPtrs(); /** * Clears all currently registered ArenaRefPtrs for the given ArenaObjectID. * This is called when we reconstruct the rule tree so that style contexts * pointing into the old rule tree aren't released afterwards, triggering an * assertion in ~nsStyleContext. */ void ClearArenaRefPtrs(mozilla::ArenaObjectID aObjectID); /** * Increment aArenaStats with sizes of interesting objects allocated in this * arena and its mOther field with the size of everything else. */ void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf, nsArenaMemoryStats* aArenaStats); private: void* Allocate(uint32_t aCode, size_t aSize); void Free(uint32_t aCode, void* aPtr); inline void ClearArenaRefPtrWithoutDeregistering( void* aPtr, mozilla::ArenaObjectID aObjectID); // All keys to this hash table fit in 32 bits (see below) so we do not // bother actually hashing them. class FreeList : public PLDHashEntryHdr { public: typedef uint32_t KeyType; nsTArray<void *> mEntries; size_t mEntrySize; size_t mEntriesEverAllocated; typedef const void* KeyTypePointer; KeyTypePointer mKey; explicit FreeList(KeyTypePointer aKey) : mEntrySize(0), mEntriesEverAllocated(0), mKey(aKey) {} // Default copy constructor and destructor are ok. bool KeyEquals(KeyTypePointer const aKey) const { return mKey == aKey; } static KeyTypePointer KeyToPointer(KeyType aKey) { return NS_INT32_TO_PTR(aKey); } static PLDHashNumber HashKey(KeyTypePointer aKey) { return NS_PTR_TO_INT32(aKey); } size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const { return mEntries.ShallowSizeOfExcludingThis(aMallocSizeOf); } enum { ALLOW_MEMMOVE = false }; }; nsTHashtable<FreeList> mFreeLists; PLArenaPool mPool; nsDataHashtable<nsPtrHashKey<void>, mozilla::ArenaObjectID> mArenaRefPtrs; }; #endif