xpcom/base/MemoryInfo.cpp

   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 #include "mozilla/MemoryInfo.h"
   8
   9 #include "mozilla/DebugOnly.h"
  10
  11 #include <winbase.h>
  12
  13 namespace mozilla {
  14
  15 /* static */
  16 MemoryInfo MemoryInfo::Get(const void* aPtr, size_t aSize) {
  17   MemoryInfo result;
  18
  19   result.mStart = uintptr_t(aPtr);
  20   const char* ptr = reinterpret_cast<const char*>(aPtr);
  21   const char* end = ptr + aSize;
  22   DebugOnly<void*> base = nullptr;
  23   while (ptr < end) {
  24     MEMORY_BASIC_INFORMATION basicInfo;
  25     if (!VirtualQuery(ptr, &basicInfo, sizeof(basicInfo))) {
  26       break;
  27     }
  28
  29     MOZ_ASSERT_IF(base, base == basicInfo.AllocationBase);
  30     base = basicInfo.AllocationBase;
  31
  32     size_t regionSize =
  33         std::min(size_t(basicInfo.RegionSize), size_t(end - ptr));
  34
  35     if (basicInfo.State == MEM_COMMIT) {
  36       result.mCommitted += regionSize;
  37     } else if (basicInfo.State == MEM_RESERVE) {
  38       result.mReserved += regionSize;
  39     } else if (basicInfo.State == MEM_FREE) {
  40       result.mFree += regionSize;
  41     } else {
  42       MOZ_ASSERT_UNREACHABLE("Unexpected region state");
  43     }
  44     result.mSize += regionSize;
  45     ptr += regionSize;
  46
  47     if (result.mType.isEmpty()) {
  48       if (basicInfo.Type & MEM_IMAGE) {
  49         result.mType += PageType::Image;
  50       }
  51       if (basicInfo.Type & MEM_MAPPED) {
  52         result.mType += PageType::Mapped;
  53       }
  54       if (basicInfo.Type & MEM_PRIVATE) {
  55         result.mType += PageType::Private;
  56       }
  57
  58       // The first 8 bits of AllocationProtect are an enum. The remaining bits
  59       // are flags.
  60       switch (basicInfo.AllocationProtect & 0xff) {
  61         case PAGE_EXECUTE_WRITECOPY:
  62           result.mPerms += Perm::CopyOnWrite;
  63           [[fallthrough]];
  64         case PAGE_EXECUTE_READWRITE:
  65           result.mPerms += Perm::Write;
  66           [[fallthrough]];
  67         case PAGE_EXECUTE_READ:
  68           result.mPerms += Perm::Read;
  69           [[fallthrough]];
  70         case PAGE_EXECUTE:
  71           result.mPerms += Perm::Execute;
  72           break;
  73
  74         case PAGE_WRITECOPY:
  75           result.mPerms += Perm::CopyOnWrite;
  76           [[fallthrough]];
  77         case PAGE_READWRITE:
  78           result.mPerms += Perm::Write;
  79           [[fallthrough]];
  80         case PAGE_READONLY:
  81           result.mPerms += Perm::Read;
  82           break;
  83
  84         default:
  85           break;
  86       }
  87
  88       if (basicInfo.AllocationProtect & PAGE_GUARD) {
  89         result.mPerms += Perm::Guard;
  90       }
  91       if (basicInfo.AllocationProtect & PAGE_NOCACHE) {
  92         result.mPerms += Perm::NoCache;
  93       }
  94       if (basicInfo.AllocationProtect & PAGE_WRITECOMBINE) {
  95         result.mPerms += Perm::WriteCombine;
  96       }
  97     }
  98   }
  99
 100   result.mEnd = uintptr_t(ptr);
 101   return result;
 102 }
 103
 104 }  // namespace mozilla