The Tor Browser / file comparison
comparison: memory/mozalloc/VolatileBufferWindows.cpp
memory/mozalloc/VolatileBufferWindows.cpp
- changeset 0
- 6474c204b198
equal
deleted
inserted
replaced
| -1:000000000000 | 0:f5ae1962ae58 |
|---|---|
| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 #if defined(XP_WIN) | |
| 6 # define MOZALLOC_EXPORT __declspec(dllexport) | |
| 7 #endif | |
| 8 | |
| 9 #include "VolatileBuffer.h" | |
| 10 #include "mozilla/Assertions.h" | |
| 11 #include "mozilla/mozalloc.h" | |
| 12 #include "mozilla/WindowsVersion.h" | |
| 13 | |
| 14 #include <windows.h> | |
| 15 | |
| 16 #ifdef MOZ_MEMORY | |
| 17 extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size); | |
| 18 #endif | |
| 19 | |
| 20 #ifndef MEM_RESET_UNDO | |
| 21 #define MEM_RESET_UNDO 0x1000000 | |
| 22 #endif | |
| 23 | |
| 24 #define MIN_VOLATILE_ALLOC_SIZE 8192 | |
| 25 | |
| 26 namespace mozilla { | |
| 27 | |
| 28 VolatileBuffer::VolatileBuffer() | |
| 29 : mBuf(nullptr) | |
| 30 , mSize(0) | |
| 31 , mLockCount(0) | |
| 32 , mHeap(false) | |
| 33 , mFirstLock(true) | |
| 34 { | |
| 35 } | |
| 36 | |
| 37 bool | |
| 38 VolatileBuffer::Init(size_t aSize, size_t aAlignment) | |
| 39 { | |
| 40 MOZ_ASSERT(!mSize && !mBuf, "Init called twice"); | |
| 41 MOZ_ASSERT(!(aAlignment % sizeof(void *)), | |
| 42 "Alignment must be multiple of pointer size"); | |
| 43 | |
| 44 mSize = aSize; | |
| 45 if (aSize < MIN_VOLATILE_ALLOC_SIZE) { | |
| 46 goto heap_alloc; | |
| 47 } | |
| 48 | |
| 49 static bool sUndoSupported = IsWin8OrLater(); | |
| 50 if (!sUndoSupported) { | |
| 51 goto heap_alloc; | |
| 52 } | |
| 53 | |
| 54 mBuf = VirtualAllocEx(GetCurrentProcess(), | |
| 55 nullptr, | |
| 56 mSize, | |
| 57 MEM_COMMIT | MEM_RESERVE, | |
| 58 PAGE_READWRITE); | |
| 59 if (mBuf) { | |
| 60 return true; | |
| 61 } | |
| 62 | |
| 63 heap_alloc: | |
| 64 #ifdef MOZ_MEMORY | |
| 65 posix_memalign(&mBuf, aAlignment, aSize); | |
| 66 #else | |
| 67 mBuf = _aligned_malloc(aSize, aAlignment); | |
| 68 #endif | |
| 69 mHeap = true; | |
| 70 return !!mBuf; | |
| 71 } | |
| 72 | |
| 73 VolatileBuffer::~VolatileBuffer() | |
| 74 { | |
| 75 if (OnHeap()) { | |
| 76 #ifdef MOZ_MEMORY | |
| 77 free(mBuf); | |
| 78 #else | |
| 79 _aligned_free(mBuf); | |
| 80 #endif | |
| 81 } else { | |
| 82 VirtualFreeEx(GetCurrentProcess(), mBuf, 0, MEM_RELEASE); | |
| 83 } | |
| 84 } | |
| 85 | |
| 86 bool | |
| 87 VolatileBuffer::Lock(void** aBuf) | |
| 88 { | |
| 89 MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer"); | |
| 90 | |
| 91 *aBuf = mBuf; | |
| 92 if (++mLockCount > 1 || OnHeap()) { | |
| 93 return true; | |
| 94 } | |
| 95 | |
| 96 // MEM_RESET_UNDO's behavior is undefined when called on memory that | |
| 97 // hasn't been MEM_RESET. | |
| 98 if (mFirstLock) { | |
| 99 mFirstLock = false; | |
| 100 return true; | |
| 101 } | |
| 102 | |
| 103 void* addr = VirtualAllocEx(GetCurrentProcess(), | |
| 104 mBuf, | |
| 105 mSize, | |
| 106 MEM_RESET_UNDO, | |
| 107 PAGE_READWRITE); | |
| 108 return !!addr; | |
| 109 } | |
| 110 | |
| 111 void | |
| 112 VolatileBuffer::Unlock() | |
| 113 { | |
| 114 MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!"); | |
| 115 if (--mLockCount || OnHeap()) { | |
| 116 return; | |
| 117 } | |
| 118 | |
| 119 void* addr = VirtualAllocEx(GetCurrentProcess(), | |
| 120 mBuf, | |
| 121 mSize, | |
| 122 MEM_RESET, | |
| 123 PAGE_READWRITE); | |
| 124 MOZ_ASSERT(addr, "Failed to MEM_RESET"); | |
| 125 } | |
| 126 | |
| 127 bool | |
| 128 VolatileBuffer::OnHeap() const | |
| 129 { | |
| 130 return mHeap; | |
| 131 } | |
| 132 | |
| 133 size_t | |
| 134 VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const | |
| 135 { | |
| 136 if (OnHeap()) { | |
| 137 #ifdef MOZ_MEMORY | |
| 138 return aMallocSizeOf(mBuf); | |
| 139 #else | |
| 140 return mSize; | |
| 141 #endif | |
| 142 } | |
| 143 | |
| 144 return 0; | |
| 145 } | |
| 146 | |
| 147 size_t | |
| 148 VolatileBuffer::NonHeapSizeOfExcludingThis() const | |
| 149 { | |
| 150 if (OnHeap()) { | |
| 151 return 0; | |
| 152 } | |
| 153 | |
| 154 return (mSize + 4095) & ~4095; | |
| 155 } | |
| 156 | |
| 157 } // namespace mozilla |
