自己封装了一个NedAllocator,底层使用nedmalloc

自己封装了一个NedAllocator,底层使用nedmalloc

[ 2010-01-20 14:36:40 | 作者: Admin ]

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这里是对nedmalloc的简介，来自http://www.nedprod.com/programs/portable/nedmalloc/

nedmalloc is a VERY fast, VERY scalable, multithreaded memory allocator with little memory fragmentation. It is faster in real world code than Hoard, faster than tcmalloc, faster than ptmalloc2 and it scales with extra processing cores better than Hoard, better than tcmalloc and better than ptmalloc2 or ptmalloc3. Put another way, there is no faster portable memory allocator out there! Unlike other allocators, it is written in C and so can be used anywhere and it also comes under the Boost software license which permits commercial usage.

在这里我就不翻译了，可惜他是C代码，上层应用很麻烦了，于是我将它封装成了一个NedAllocatorObject.Lib，方便大家使用。

要封装nedmalloc, 先实现一个NedAllocatorImpl
NedAllocatorImpl.h代码如下

#ifndef _NEDALLOCATOR_IMPL_H_
#define _NEDALLOCATOR_IMPL_H_

class NedAllocatorImpl
{
public:
  static void* allocBytes(size_t count);
  static void deallocBytes(void* ptr);
  static void* allocBytesAligned(size_t align, size_t count);
  static void deallocBytesAligned(size_t align, void* ptr);
};

#endif //_NEDALLOCATOR_IMPL_H_

实现如下（NedAllocatorImpl.cpp）

#include "NedAllocatorImpl.h"
#include "nedmalloc.c"

void* NedAllocatorImpl::allocBytes(size_t count)
{
  void* ptr = nedalloc::nedmalloc(count);
  return ptr;
}

void NedAllocatorImpl::deallocBytes(void* ptr)
{
  if(!ptr)
    return;

  nedalloc::nedfree(ptr);
}

void* NedAllocatorImpl::allocBytesAligned(size_t align, size_t count)
{
  const size_t SIMD_ALIGNMENT = 16;
  void* ptr = align ? nedalloc::nedmemalign(align, count)
    : nedalloc::nedmemalign(SIMD_ALIGNMENT, count);

  return ptr;
}

void NedAllocatorImpl::deallocBytesAligned(size_t align, void* ptr)
{
  if (!ptr)
    return;

  nedalloc::nedfree(ptr);
}

最后我们在封装成一个NedAllocatedObject

#ifndef _NEDALLOCATED_OBJECT_H_
#define _NEDALLOCATED_OBJECT_H_

#include "NedAllocatorImpl.h"

class NedAllocatedObject
{
public:
  explicit NedAllocatedObject()
  {

  }
  ~NedAllocatedObject()
  {

  }

  void* operator new(size_t sz)
  {
    return NedAllocatorImpl::allocBytes(sz);
  }

  /// placement operator new
  void* operator new(size_t sz, void* ptr)
  {
    return ptr;
  }

  void* operator new[] ( size_t sz )
  {
    return NedAllocatorImpl::allocBytes(sz);
  }

  void operator delete( void* ptr )
  {
    NedAllocatorImpl::deallocBytes(ptr);
  }

  void operator delete( void* ptr, void* )
  {
    NedAllocatorImpl::deallocBytes(ptr);
  }

  void operator delete[] ( void* ptr )
  {
    NedAllocatorImpl::deallocBytes(ptr);
  }
};

#endif //_NEDALLOCATED_OBJECT_H_

源代码以及测试代码如下：