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