ceph/src/boost/libs/align/include/boost/align/detail/aligned_alloc.hpp

   1 /*
   2 (c) 2014-2015 Glen Joseph Fernandes
   3 <glenjofe -at- gmail.com>
   4
   5 Distributed under the Boost Software
   6 License, Version 1.0.
   7 http://boost.org/LICENSE_1_0.txt
   8 */
   9 #ifndef BOOST_ALIGN_DETAIL_ALIGNED_ALLOC_HPP
  10 #define BOOST_ALIGN_DETAIL_ALIGNED_ALLOC_HPP
  11
  12 #include <boost/align/detail/is_alignment.hpp>
  13 #include <boost/align/align.hpp>
  14 #include <boost/align/alignment_of.hpp>
  15 #include <boost/assert.hpp>
  16 #include <cstdlib>
  17
  18 namespace boost {
  19 namespace alignment {
  20
  21 inline void* aligned_alloc(std::size_t alignment, std::size_t size)
  22     BOOST_NOEXCEPT
  23 {
  24     BOOST_ASSERT(detail::is_alignment(alignment));
  25     enum {
  26         min_align = alignment_of<void*>::value
  27     };
  28     if (alignment < min_align) {
  29         alignment = min_align;
  30     }
  31     std::size_t n = size + alignment - min_align;
  32     void* r = 0;
  33     void* p = std::malloc(sizeof(void*) + n);
  34     if (p) {
  35         r = static_cast<char*>(p) + sizeof p;
  36         (void)align(alignment, size, r, n);
  37         *(static_cast<void**>(r) - 1) = p;
  38     }
  39     return r;
  40 }
  41
  42 inline void aligned_free(void* ptr) BOOST_NOEXCEPT
  43 {
  44     if (ptr) {
  45         std::free(*(static_cast<void**>(ptr) - 1));
  46     }
  47 }
  48
  49 } /* .alignment */
  50 } /* .boost */
  51
  52 #endif