libstdc++-v3/src/bitmap_allocator.cc

   1 // Bitmap Allocator. Out of line function definitions. -*- C++ -*-
   2
   3 // Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 #include <ext/bitmap_allocator.h>
  27
  28 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  29 {
  30   namespace __detail
  31   {
  32   _GLIBCXX_BEGIN_NAMESPACE_VERSION
  33     template class __mini_vector<
  34       std::pair<bitmap_allocator<char>::_Alloc_block*,
  35                 bitmap_allocator<char>::_Alloc_block*> >;
  36
  37     template class __mini_vector<
  38       std::pair<bitmap_allocator<wchar_t>::_Alloc_block*,
  39                 bitmap_allocator<wchar_t>::_Alloc_block*> >;
  40
  41     template class __mini_vector<size_t*>;
  42
  43     template size_t** __lower_bound(size_t**, size_t**, size_t const&,
  44                                     free_list::_LT_pointer_compare);
  45   _GLIBCXX_END_NAMESPACE_VERSION
  46   }
  47
  48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  49
  50   size_t*
  51   free_list::
  52   _M_get(size_t __sz) throw(std::bad_alloc)
  53   {
  54 #if defined __GTHREADS
  55     __mutex_type& __bfl_mutex = _M_get_mutex();
  56     __bfl_mutex.lock();
  57 #endif
  58     const vector_type& __free_list = _M_get_free_list();
  59     using __gnu_cxx::__detail::__lower_bound;
  60     iterator __tmp = __lower_bound(__free_list.begin(), __free_list.end(),
  61                                    __sz, _LT_pointer_compare());
  62
  63     if (__tmp == __free_list.end() || !_M_should_i_give(**__tmp, __sz))
  64       {
  65         // We release the lock here, because operator new is
  66         // guaranteed to be thread-safe by the underlying
  67         // implementation.
  68 #if defined __GTHREADS
  69         __bfl_mutex.unlock();
  70 #endif
  71         // Try twice to get the memory: once directly, and the 2nd
  72         // time after clearing the free list. If both fail, then throw
  73         // std::bad_alloc().
  74         int __ctr = 2;
  75         while (__ctr)
  76           {
  77             size_t* __ret = 0;
  78             --__ctr;
  79             __try
  80               {
  81                 __ret = reinterpret_cast<size_t*>
  82                   (::operator new(__sz + sizeof(size_t)));
  83               }
  84             __catch(const std::bad_alloc&)
  85               {
  86                 this->_M_clear();
  87               }
  88             if (!__ret)
  89               continue;
  90             *__ret = __sz;
  91             return __ret + 1;
  92           }
  93         std::__throw_bad_alloc();
  94       }
  95     else
  96       {
  97         size_t* __ret = *__tmp;
  98         _M_get_free_list().erase(__tmp);
  99 #if defined __GTHREADS
 100         __bfl_mutex.unlock();
 101 #endif
 102         return __ret + 1;
 103       }
 104   }
 105
 106   void
 107   free_list::
 108   _M_clear()
 109   {
 110 #if defined __GTHREADS
 111     __gnu_cxx::__scoped_lock __bfl_lock(_M_get_mutex());
 112 #endif
 113     vector_type& __free_list = _M_get_free_list();
 114     iterator __iter = __free_list.begin();
 115     while (__iter != __free_list.end())
 116       {
 117         ::operator delete((void*)*__iter);
 118         ++__iter;
 119       }
 120     __free_list.clear();
 121   }
 122
 123   // Instantiations.
 124   template class bitmap_allocator<char>;
 125   template class bitmap_allocator<wchar_t>;
 126
 127 _GLIBCXX_END_NAMESPACE_VERSION
 128 } // namespace