gnu/dist/gcc4/libstdc++-v3/src/bitmap_allocator.cc

   1 // Bitmap Allocator. Out of line function definitions. -*- C++ -*-
   2
   3 // Copyright (C) 2004, 2005 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #include <ext/bitmap_allocator.h>
  31
  32 namespace __gnu_cxx
  33 {
  34   namespace balloc
  35   {
  36     template class __mini_vector<std::pair
  37     <bitmap_allocator<char>::_Alloc_block*,
  38      bitmap_allocator<char>::_Alloc_block*> >;
  39
  40     template class __mini_vector<std::pair
  41     <bitmap_allocator<wchar_t>::_Alloc_block*,
  42      bitmap_allocator<wchar_t>::_Alloc_block*> >;
  43
  44     template class __mini_vector<size_t*>;
  45
  46     template size_t** __lower_bound
  47     (size_t**, size_t**,
  48      size_t const&, free_list::_LT_pointer_compare);
  49   }
  50
  51   size_t*
  52   free_list::
  53   _M_get(size_t __sz) throw(std::bad_alloc)
  54   {
  55 #if defined __GTHREADS
  56     _Lock __bfl_lock(_M_get_mutex());
  57     __bfl_lock._M_lock();
  58 #endif
  59     iterator __temp =
  60       __gnu_cxx::balloc::__lower_bound
  61       (_M_get_free_list().begin(), _M_get_free_list().end(),
  62        __sz, _LT_pointer_compare());
  63
  64     if (__temp == _M_get_free_list().end() || !_M_should_i_give(**__temp, __sz))
  65       {
  66         // We release the lock here, because operator new is
  67         // guaranteed to be thread-safe by the underlying
  68         // implementation.
  69 #if defined __GTHREADS
  70         __bfl_lock._M_unlock();
  71 #endif
  72         // Try twice to get the memory: once directly, and the 2nd
  73         // time after clearing the free list. If both fail, then
  74         // throw std::bad_alloc().
  75         int __ctr = 2;
  76         while (__ctr)
  77           {
  78             size_t* __ret = 0;
  79             --__ctr;
  80             try
  81               {
  82                 __ret = reinterpret_cast<size_t*>
  83                   (::operator new(__sz + sizeof(size_t)));
  84               }
  85             catch(...)
  86               {
  87                 this->_M_clear();
  88               }
  89             if (!__ret)
  90               continue;
  91             *__ret = __sz;
  92             return __ret + 1;
  93           }
  94         std::__throw_bad_alloc();
  95       }
  96     else
  97       {
  98         size_t* __ret = *__temp;
  99         _M_get_free_list().erase(__temp);
 100 #if defined __GTHREADS
 101         __bfl_lock._M_unlock();
 102 #endif
 103         return __ret + 1;
 104       }
 105   }
 106
 107   void
 108   free_list::
 109   _M_clear()
 110   {
 111 #if defined __GTHREADS
 112     _Auto_Lock __bfl_lock(_M_get_mutex());
 113 #endif
 114     vector_type& __free_list = _M_get_free_list();
 115     iterator __iter = __free_list.begin();
 116     while (__iter != __free_list.end())
 117       {
 118         ::operator delete((void*)*__iter);
 119         ++__iter;
 120       }
 121     __free_list.clear();
 122   }
 123
 124   // Instantiations.
 125   template class bitmap_allocator<char>;
 126   template class bitmap_allocator<wchar_t>;
 127 } // namespace __gnu_cxx