归国对齐的内存与新？ [英] returning aligned memory with new?

问题描述

目前，我分配我的记忆中使用的MS具体mm_malloc阵列。我对齐的记忆，因为我正在做一些重型数学和矢量拍摄校准的优势。我想知道是否有人知道如何重载新的运营商做同样的事情，因为我觉得脏malloc'ing无处不在（并最终想也编译在Linux上）？感谢您的帮助

I currently allocate my memory for arrays using the MS specific mm_malloc. I align the memory, as I'm doing some heavy duty math and the vectorization takes advantage of the alignment. I was wondering if anyone knows how to overload the new operator to do the same thing, as I feel dirty malloc'ing everywhere (and would eventually like to also compile on Linux)? Thanks for any help

推荐答案

首先，需要注意的是新和删除<非常重要/ code>可以被重载无论是在全球范围，或只是一个类。这两种情况都显示在这篇文章。另外需要注意的是，如果你超载新你几乎肯定要超载删除。

First of all, it's important to note that new and delete can be overloaded either globally, or just for a single class. Both cases are shown in this article. Also important to note is that if you overload new you almost certainly also want to overload delete.

有大约几个重要事项运营商新的和的operator delete ：

There are a few important notes about operator new and operator delete:

1. 在C ++标准要求，即使传递给它的大小为0的有效指针的值。
2. 还有运营商新的[] 和的operator delete [] ，所以不要忘了超载的。
3. 在派生类继承运营商新的和它的兄弟们，所以一定要覆盖这些。

1. The C++ standard requires that a valid pointer is returned even if the size passed to it is 0.
2. There's also operator new[] and operator delete[], so don't forget about overloading those.
3. Derived classes inherit operator new and its brethren, so make sure to override those.

在 C ++有效的，第8项，斯科特迈尔斯包括一些pseudocodish例子：

In Effective C++, item 8, Scott Meyers includes some pseudocodish examples:

void * operator new(size_t size)        // your operator new might
{                                       // take additional params
  if (size == 0) {                      // handle 0-byte requests
    size = 1;                           // by treating them as
  }                                     // 1-byte requests
  while (1) {
    attempt to allocate size bytes;
    if (the allocation was successful)
      return (a pointer to the memory);

    // allocation was unsuccessful; find out what the
    // current error-handling function is (see Item 7)
    new_handler globalHandler = set_new_handler(0);
    set_new_handler(globalHandler);

    if (globalHandler) (*globalHandler)();
    else throw std::bad_alloc();
  }
}


void operator delete(void *rawMemory)
{
  if (rawMemory == 0) return;    // do nothing if the null
                                 // pointer is being deleted
  deallocate the memory pointed to by rawMemory;
  return;
}

有关详细信息，我肯定会拿起的 C ++有效的。

For more information, I'd definitely pick up Effective C++.

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