1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/sandbox/chromium/base/memory/aligned_memory.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,114 @@
1.4 +// Copyright (c) 2012 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +// AlignedMemory is a POD type that gives you a portable way to specify static
1.9 +// or local stack data of a given alignment and size. For example, if you need
1.10 +// static storage for a class, but you want manual control over when the object
1.11 +// is constructed and destructed (you don't want static initialization and
1.12 +// destruction), use AlignedMemory:
1.13 +//
1.14 +// static AlignedMemory<sizeof(MyClass), ALIGNOF(MyClass)> my_class;
1.15 +//
1.16 +// // ... at runtime:
1.17 +// new(my_class.void_data()) MyClass();
1.18 +//
1.19 +// // ... use it:
1.20 +// MyClass* mc = my_class.data_as<MyClass>();
1.21 +//
1.22 +// // ... later, to destruct my_class:
1.23 +// my_class.data_as<MyClass>()->MyClass::~MyClass();
1.24 +//
1.25 +// Alternatively, a runtime sized aligned allocation can be created:
1.26 +//
1.27 +// float* my_array = static_cast<float*>(AlignedAlloc(size, alignment));
1.28 +//
1.29 +// // ... later, to release the memory:
1.30 +// AlignedFree(my_array);
1.31 +//
1.32 +// Or using scoped_ptr_malloc:
1.33 +//
1.34 +// scoped_ptr_malloc<float, ScopedPtrAlignedFree> my_array(
1.35 +// static_cast<float*>(AlignedAlloc(size, alignment)));
1.36 +
1.37 +#ifndef BASE_MEMORY_ALIGNED_MEMORY_H_
1.38 +#define BASE_MEMORY_ALIGNED_MEMORY_H_
1.39 +
1.40 +#include "base/base_export.h"
1.41 +#include "base/basictypes.h"
1.42 +#include "base/compiler_specific.h"
1.43 +
1.44 +#if defined(COMPILER_MSVC)
1.45 +#include <malloc.h>
1.46 +#else
1.47 +#include <stdlib.h>
1.48 +#endif
1.49 +
1.50 +namespace base {
1.51 +
1.52 +// AlignedMemory is specialized for all supported alignments.
1.53 +// Make sure we get a compiler error if someone uses an unsupported alignment.
1.54 +template <size_t Size, size_t ByteAlignment>
1.55 +struct AlignedMemory {};
1.56 +
1.57 +#define BASE_DECL_ALIGNED_MEMORY(byte_alignment) \
1.58 + template <size_t Size> \
1.59 + class AlignedMemory<Size, byte_alignment> { \
1.60 + public: \
1.61 + ALIGNAS(byte_alignment) uint8 data_[Size]; \
1.62 + void* void_data() { return static_cast<void*>(data_); } \
1.63 + const void* void_data() const { \
1.64 + return static_cast<const void*>(data_); \
1.65 + } \
1.66 + template<typename Type> \
1.67 + Type* data_as() { return static_cast<Type*>(void_data()); } \
1.68 + template<typename Type> \
1.69 + const Type* data_as() const { \
1.70 + return static_cast<const Type*>(void_data()); \
1.71 + } \
1.72 + private: \
1.73 + void* operator new(size_t); \
1.74 + void operator delete(void*); \
1.75 + }
1.76 +
1.77 +// Specialization for all alignments is required because MSVC (as of VS 2008)
1.78 +// does not understand ALIGNAS(ALIGNOF(Type)) or ALIGNAS(template_param).
1.79 +// Greater than 4096 alignment is not supported by some compilers, so 4096 is
1.80 +// the maximum specified here.
1.81 +BASE_DECL_ALIGNED_MEMORY(1);
1.82 +BASE_DECL_ALIGNED_MEMORY(2);
1.83 +BASE_DECL_ALIGNED_MEMORY(4);
1.84 +BASE_DECL_ALIGNED_MEMORY(8);
1.85 +BASE_DECL_ALIGNED_MEMORY(16);
1.86 +BASE_DECL_ALIGNED_MEMORY(32);
1.87 +BASE_DECL_ALIGNED_MEMORY(64);
1.88 +BASE_DECL_ALIGNED_MEMORY(128);
1.89 +BASE_DECL_ALIGNED_MEMORY(256);
1.90 +BASE_DECL_ALIGNED_MEMORY(512);
1.91 +BASE_DECL_ALIGNED_MEMORY(1024);
1.92 +BASE_DECL_ALIGNED_MEMORY(2048);
1.93 +BASE_DECL_ALIGNED_MEMORY(4096);
1.94 +
1.95 +#undef BASE_DECL_ALIGNED_MEMORY
1.96 +
1.97 +BASE_EXPORT void* AlignedAlloc(size_t size, size_t alignment);
1.98 +
1.99 +inline void AlignedFree(void* ptr) {
1.100 +#if defined(COMPILER_MSVC)
1.101 + _aligned_free(ptr);
1.102 +#else
1.103 + free(ptr);
1.104 +#endif
1.105 +}
1.106 +
1.107 +// Helper class for use with scoped_ptr_malloc.
1.108 +class BASE_EXPORT ScopedPtrAlignedFree {
1.109 + public:
1.110 + inline void operator()(void* ptr) const {
1.111 + AlignedFree(ptr);
1.112 + }
1.113 +};
1.114 +
1.115 +} // namespace base
1.116 +
1.117 +#endif // BASE_MEMORY_ALIGNED_MEMORY_H_
