memory/mozalloc/VolatileBufferWindows.cpp@b8a032363ba2 (annotated)
memory/mozalloc/VolatileBufferWindows.cpp
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | |
| michael@0 | 5 | #if defined(XP_WIN) |
| michael@0 | 6 | # define MOZALLOC_EXPORT __declspec(dllexport) |
| michael@0 | 7 | #endif |
| michael@0 | 8 | |
| michael@0 | 9 | #include "VolatileBuffer.h" |
| michael@0 | 10 | #include "mozilla/Assertions.h" |
| michael@0 | 11 | #include "mozilla/mozalloc.h" |
| michael@0 | 12 | #include "mozilla/WindowsVersion.h" |
| michael@0 | 13 | |
| michael@0 | 14 | #include <windows.h> |
| michael@0 | 15 | |
| michael@0 | 16 | #ifdef MOZ_MEMORY |
| michael@0 | 17 | extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size); |
| michael@0 | 18 | #endif |
| michael@0 | 19 | |
| michael@0 | 20 | #ifndef MEM_RESET_UNDO |
| michael@0 | 21 | #define MEM_RESET_UNDO 0x1000000 |
| michael@0 | 22 | #endif |
| michael@0 | 23 | |
| michael@0 | 24 | #define MIN_VOLATILE_ALLOC_SIZE 8192 |
| michael@0 | 25 | |
| michael@0 | 26 | namespace mozilla { |
| michael@0 | 27 | |
| michael@0 | 28 | VolatileBuffer::VolatileBuffer() |
| michael@0 | 29 | : mBuf(nullptr) |
| michael@0 | 30 | , mSize(0) |
| michael@0 | 31 | , mLockCount(0) |
| michael@0 | 32 | , mHeap(false) |
| michael@0 | 33 | , mFirstLock(true) |
| michael@0 | 34 | { |
| michael@0 | 35 | } |
| michael@0 | 36 | |
| michael@0 | 37 | bool |
| michael@0 | 38 | VolatileBuffer::Init(size_t aSize, size_t aAlignment) |
| michael@0 | 39 | { |
| michael@0 | 40 | MOZ_ASSERT(!mSize && !mBuf, "Init called twice"); |
| michael@0 | 41 | MOZ_ASSERT(!(aAlignment % sizeof(void *)), |
| michael@0 | 42 | "Alignment must be multiple of pointer size"); |
| michael@0 | 43 | |
| michael@0 | 44 | mSize = aSize; |
| michael@0 | 45 | if (aSize < MIN_VOLATILE_ALLOC_SIZE) { |
| michael@0 | 46 | goto heap_alloc; |
| michael@0 | 47 | } |
| michael@0 | 48 | |
| michael@0 | 49 | static bool sUndoSupported = IsWin8OrLater(); |
| michael@0 | 50 | if (!sUndoSupported) { |
| michael@0 | 51 | goto heap_alloc; |
| michael@0 | 52 | } |
| michael@0 | 53 | |
| michael@0 | 54 | mBuf = VirtualAllocEx(GetCurrentProcess(), |
| michael@0 | 55 | nullptr, |
| michael@0 | 56 | mSize, |
| michael@0 | 57 | MEM_COMMIT | MEM_RESERVE, |
| michael@0 | 58 | PAGE_READWRITE); |
| michael@0 | 59 | if (mBuf) { |
| michael@0 | 60 | return true; |
| michael@0 | 61 | } |
| michael@0 | 62 | |
| michael@0 | 63 | heap_alloc: |
| michael@0 | 64 | #ifdef MOZ_MEMORY |
| michael@0 | 65 | posix_memalign(&mBuf, aAlignment, aSize); |
| michael@0 | 66 | #else |
| michael@0 | 67 | mBuf = _aligned_malloc(aSize, aAlignment); |
| michael@0 | 68 | #endif |
| michael@0 | 69 | mHeap = true; |
| michael@0 | 70 | return !!mBuf; |
| michael@0 | 71 | } |
| michael@0 | 72 | |
| michael@0 | 73 | VolatileBuffer::~VolatileBuffer() |
| michael@0 | 74 | { |
| michael@0 | 75 | if (OnHeap()) { |
| michael@0 | 76 | #ifdef MOZ_MEMORY |
| michael@0 | 77 | free(mBuf); |
| michael@0 | 78 | #else |
| michael@0 | 79 | _aligned_free(mBuf); |
| michael@0 | 80 | #endif |
| michael@0 | 81 | } else { |
| michael@0 | 82 | VirtualFreeEx(GetCurrentProcess(), mBuf, 0, MEM_RELEASE); |
| michael@0 | 83 | } |
| michael@0 | 84 | } |
| michael@0 | 85 | |
| michael@0 | 86 | bool |
| michael@0 | 87 | VolatileBuffer::Lock(void** aBuf) |
| michael@0 | 88 | { |
| michael@0 | 89 | MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer"); |
| michael@0 | 90 | |
| michael@0 | 91 | *aBuf = mBuf; |
| michael@0 | 92 | if (++mLockCount > 1 || OnHeap()) { |
| michael@0 | 93 | return true; |
| michael@0 | 94 | } |
| michael@0 | 95 | |
| michael@0 | 96 | // MEM_RESET_UNDO's behavior is undefined when called on memory that |
| michael@0 | 97 | // hasn't been MEM_RESET. |
| michael@0 | 98 | if (mFirstLock) { |
| michael@0 | 99 | mFirstLock = false; |
| michael@0 | 100 | return true; |
| michael@0 | 101 | } |
| michael@0 | 102 | |
| michael@0 | 103 | void* addr = VirtualAllocEx(GetCurrentProcess(), |
| michael@0 | 104 | mBuf, |
| michael@0 | 105 | mSize, |
| michael@0 | 106 | MEM_RESET_UNDO, |
| michael@0 | 107 | PAGE_READWRITE); |
| michael@0 | 108 | return !!addr; |
| michael@0 | 109 | } |
| michael@0 | 110 | |
| michael@0 | 111 | void |
| michael@0 | 112 | VolatileBuffer::Unlock() |
| michael@0 | 113 | { |
| michael@0 | 114 | MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!"); |
| michael@0 | 115 | if (--mLockCount || OnHeap()) { |
| michael@0 | 116 | return; |
| michael@0 | 117 | } |
| michael@0 | 118 | |
| michael@0 | 119 | void* addr = VirtualAllocEx(GetCurrentProcess(), |
| michael@0 | 120 | mBuf, |
| michael@0 | 121 | mSize, |
| michael@0 | 122 | MEM_RESET, |
| michael@0 | 123 | PAGE_READWRITE); |
| michael@0 | 124 | MOZ_ASSERT(addr, "Failed to MEM_RESET"); |
| michael@0 | 125 | } |
| michael@0 | 126 | |
| michael@0 | 127 | bool |
| michael@0 | 128 | VolatileBuffer::OnHeap() const |
| michael@0 | 129 | { |
| michael@0 | 130 | return mHeap; |
| michael@0 | 131 | } |
| michael@0 | 132 | |
| michael@0 | 133 | size_t |
| michael@0 | 134 | VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const |
| michael@0 | 135 | { |
| michael@0 | 136 | if (OnHeap()) { |
| michael@0 | 137 | #ifdef MOZ_MEMORY |
| michael@0 | 138 | return aMallocSizeOf(mBuf); |
| michael@0 | 139 | #else |
| michael@0 | 140 | return mSize; |
| michael@0 | 141 | #endif |
| michael@0 | 142 | } |
| michael@0 | 143 | |
| michael@0 | 144 | return 0; |
| michael@0 | 145 | } |
| michael@0 | 146 | |
| michael@0 | 147 | size_t |
| michael@0 | 148 | VolatileBuffer::NonHeapSizeOfExcludingThis() const |
| michael@0 | 149 | { |
| michael@0 | 150 | if (OnHeap()) { |
| michael@0 | 151 | return 0; |
| michael@0 | 152 | } |
| michael@0 | 153 | |
| michael@0 | 154 | return (mSize + 4095) & ~4095; |
| michael@0 | 155 | } |
| michael@0 | 156 | |
| michael@0 | 157 | } // namespace mozilla |
