tor-browser

The Tor Browser
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nsPresArena.h (1959B)


      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
      6 */
      7 
      8 /* arena allocation for the frame tree and closely-related objects */
      9 
     10 #ifndef nsPresArena_h___
     11 #define nsPresArena_h___
     12 
     13 #include "mozilla/ArenaAllocator.h"
     14 #include "mozilla/ArenaObjectID.h"
     15 #include "mozilla/MemoryChecking.h"  // Note: Do not remove this, needed for MOZ_HAVE_MEM_CHECKS below
     16 #include "mozilla/MemoryReporting.h"
     17 #include "nsHashKeys.h"
     18 #include "nsTArray.h"
     19 #include "nsTHashtable.h"
     20 #include "nscore.h"
     21 
     22 class nsWindowSizes;
     23 
     24 template <size_t ArenaSize, typename ObjectId, size_t ObjectIdCount>
     25 class nsPresArena {
     26 public:
     27  nsPresArena() = default;
     28  ~nsPresArena();
     29 
     30  /**
     31   * Pool allocation with recycler lists indexed by object-type ID (see above).
     32   * Every aID must always be used with the same object size, aSize.
     33   */
     34  void* Allocate(ObjectId aCode, size_t aSize);
     35  void Free(ObjectId aCode, void* aPtr);
     36 
     37  enum class ArenaKind { PresShell, DisplayList };
     38  /**
     39   * Increment nsWindowSizes with sizes of interesting objects allocated in this
     40   * arena, and put the general unclassified size in the relevant field
     41   * depending on the arena size.
     42   */
     43  void AddSizeOfExcludingThis(nsWindowSizes&, ArenaKind) const;
     44 
     45  void Check() { mPool.Check(); }
     46 
     47 private:
     48  class FreeList {
     49   public:
     50    nsTArray<void*> mEntries;
     51    size_t mEntrySize;
     52    size_t mEntriesEverAllocated;
     53 
     54    FreeList() : mEntrySize(0), mEntriesEverAllocated(0) {}
     55 
     56    size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
     57      return mEntries.ShallowSizeOfExcludingThis(aMallocSizeOf);
     58    }
     59  };
     60 
     61  FreeList mFreeLists[ObjectIdCount];
     62  mozilla::ArenaAllocator<ArenaSize, 8> mPool;
     63 };
     64 
     65 #endif