AlignedAlloc.hpp

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/*
    Copyright (c) 2009-2010 Christopher A. Taylor.  All rights reserved.

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    modification, are permitted provided that the following conditions are met:

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      this list of conditions and the following disclaimer.
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      to endorse or promote products derived from this software without
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    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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#ifndef CAT_ALIGNED_ALLOC_HPP
#define CAT_ALIGNED_ALLOC_HPP

#include <cat/Platform.hpp>

#include <cstddef> // size_t
#include <vector> // std::_Construct and std::_Destroy


namespace cat {


// Small to medium -size aligned heap allocator
class Aligned
{
public:
    CAT_INLINE Aligned() {}

    // Acquires memory aligned to a CPU cache-line byte boundary from the heap
    static void *Acquire(u32 bytes);

    // Resizes an aligned pointer
    static void *Resize(void *ptr, u32 bytes);

    // Release an aligned pointer
    static void Release(void *ptr);

    template<class T>
    static inline void Delete(T *ptr)
    {
        ptr->~T();
        Release(ptr);
    }

    static Aligned ii;
};

// Use STLAlignedAllocator in place of the standard STL allocator
// to make use of the Aligned in STL types.
template<typename T>
class STLAlignedAllocator
{
public:
    typedef std::size_t size_type;
    typedef std::size_t difference_type;
    typedef T *pointer;
    typedef const T *const_pointer;
    typedef T &reference;
    typedef const T &const_reference;
    typedef T value_type;

    template<typename S>
    struct rebind
    {
        typedef STLAlignedAllocator<S> other;
    };

    pointer address(reference X) const
    {
        return &X;
    }

    const_pointer address(const_reference X) const
    {
        return &X;
    }

    STLAlignedAllocator() throw ()
    {
    }

    template<typename S>
    STLAlignedAllocator(const STLAlignedAllocator<S> &cp) throw ()
    {
    }

    template<typename S>
    STLAlignedAllocator<T> &operator=(const STLAlignedAllocator<S> &cp) throw ()
    {
        return *this;
    }

    pointer allocate(size_type Count, const void *Hint = 0)
    {
        return (pointer)Aligned::Acquire((u32)Count * sizeof(T));
    }

    void deallocate(pointer Ptr, size_type Count)
    {
        Aligned::Release(Ptr);
    }

    void construct(pointer Ptr, const T &Val)
    {
        std::_Construct(Ptr, Val);
    }

    void destroy(pointer Ptr)
    {
        std::_Destroy(Ptr);
    }

    size_type max_size() const
    {
        return 0x00FFFFFF;
    }

    template<typename S>
    bool operator==(STLAlignedAllocator <S> const &) const throw()
    {
        return true;
    }

    template<typename S>
    bool operator!=(STLAlignedAllocator <S> const &) const throw()
    {
        return false;
    }
};


// Large-size aligned heap allocator
class LargeAligned
{
public:
    // Acquires memory aligned to a CPU cache-line byte boundary from the heap
    static void *Acquire(u32 bytes);

    // Release an aligned pointer
    static void Release(void *ptr);
};

// Use STLAlignedAllocator in place of the standard STL allocator
// to make use of the Aligned in STL types.
template<typename T>
class STLLargeAlignedAllocator
{
public:
    typedef std::size_t size_type;
    typedef std::size_t difference_type;
    typedef T *pointer;
    typedef const T *const_pointer;
    typedef T &reference;
    typedef const T &const_reference;
    typedef T value_type;

    template<typename S>
    struct rebind
    {
        typedef STLLargeAlignedAllocator<S> other;
    };

    pointer address(reference X) const
    {
        return &X;
    }

    const_pointer address(const_reference X) const
    {
        return &X;
    }

    STLLargeAlignedAllocator() throw ()
    {
    }

    template<typename S>
    STLLargeAlignedAllocator(const STLLargeAlignedAllocator<S> &cp) throw ()
    {
    }

    template<typename S>
    STLLargeAlignedAllocator<T> &operator=(const STLLargeAlignedAllocator<S> &cp) throw ()
    {
        return *this;
    }

    pointer allocate(size_type Count, const void *Hint = 0)
    {
        return (pointer)LargeAligned::Acquire((u32)Count * sizeof(T));
    }

    void deallocate(pointer Ptr, size_type Count)
    {
        LargeAligned::Release(Ptr);
    }

    void construct(pointer Ptr, const T &Val)
    {
        std::_Construct(Ptr, Val);
    }

    void destroy(pointer Ptr)
    {
        std::_Destroy(Ptr);
    }

    size_type max_size() const
    {
        return 0x00FFFFFF;
    }

    template<typename S>
    bool operator==(STLLargeAlignedAllocator <S> const &) const throw()
    {
        return true;
    }

    template<typename S>
    bool operator!=(STLLargeAlignedAllocator <S> const &) const throw()
    {
        return false;
    }
};


u32 GetCacheLineBytes();


} // namespace cat

// Provide placement new constructor and delete pair to allow for
// an easy syntax to create objects from the RegionAllocator:
//   T *a = new (Aligned()) T();
// The object can be freed with:
//   Aligned::Delete(a);
// Which insures that the destructor is called before freeing memory
CAT_INLINE void *operator new[](std::size_t bytes, cat::Aligned &) throw()
{
    return cat::Aligned::Acquire((int)bytes);
}

// Placement "delete": Does not call destructor
CAT_INLINE void operator delete(void *ptr, cat::Aligned &) throw()
{
    cat::Aligned::Release(ptr);
}

#endif // CAT_ENDIAN_NEUTRAL_HPP