xpcom/base/MemoryInfo.h

   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 #ifndef mozilla_MemoryInfo_h
   8 #define mozilla_MemoryInfo_h
   9
  10 #include <cstddef>
  11 #include <cstdint>
  12 #include "mozilla/Attributes.h"
  13 #include "mozilla/EnumSet.h"
  14 /**
  15  * MemoryInfo is a helper class which describes the attributes and sizes of a
  16  * particular region of VM memory on Windows. It roughtly corresponds to the
  17  * values in a MEMORY_BASIC_INFORMATION struct, summed over an entire region or
  18  * memory.
  19  */
  20
  21 namespace mozilla {
  22
  23 class MemoryInfo final {
  24  public:
  25   enum class Perm : uint8_t {
  26     Read,
  27     Write,
  28     Execute,
  29     CopyOnWrite,
  30     Guard,
  31     NoCache,
  32     WriteCombine,
  33   };
  34   enum class PageType : uint8_t {
  35     Image,
  36     Mapped,
  37     Private,
  38   };
  39
  40   using PermSet = EnumSet<Perm>;
  41   using PageTypeSet = EnumSet<PageType>;
  42
  43   MemoryInfo() = default;
  44   MOZ_IMPLICIT MemoryInfo(const MemoryInfo&) = default;
  45
  46   uintptr_t Start() const { return mStart; }
  47   uintptr_t End() const { return mEnd; }
  48
  49   PageTypeSet Type() const { return mType; }
  50   PermSet Perms() const { return mPerms; }
  51
  52   size_t Reserved() const { return mReserved; }
  53   size_t Committed() const { return mCommitted; }
  54   size_t Free() const { return mFree; }
  55   size_t Size() const { return mSize; }
  56
  57   // Returns a MemoryInfo object containing the sums of all region sizes,
  58   // divided into Reserved, Committed, and Free, depending on their State
  59   // properties.
  60   //
  61   // The entire range of aSize bytes starting at aPtr must correspond to a
  62   // single allocation. This restriction is enforced in debug builds.
  63   static MemoryInfo Get(const void* aPtr, size_t aSize);
  64
  65  private:
  66   uintptr_t mStart = 0;
  67   uintptr_t mEnd = 0;
  68
  69   size_t mReserved = 0;
  70   size_t mCommitted = 0;
  71   size_t mFree = 0;
  72   size_t mSize = 0;
  73
  74   PageTypeSet mType{};
  75
  76   PermSet mPerms{};
  77 };
  78
  79 }  // namespace mozilla
  80
  81 #endif  // mozilla_MemoryInfo_h