libstdc++-v3/src/bitmap_allocator.cc

   1 // Bitmap Allocator. Out of line function definitions. -*- C++ -*-
   2
   3 // Copyright (C) 2004 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  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 #if defined __GTHREADS
  52   _Mutex free_list::_S_bfl_mutex;
  53 #endif
  54   free_list::vector_type free_list::_S_free_list;
  55
  56   size_t*
  57   free_list::
  58   _M_get(size_t __sz) throw(std::bad_alloc)
  59   {
  60 #if defined __GTHREADS
  61     _Lock __bfl_lock(&_S_bfl_mutex);
  62     __bfl_lock._M_lock();
  63 #endif
  64     iterator __temp =
  65       __gnu_cxx::balloc::__lower_bound
  66       (_S_free_list.begin(), _S_free_list.end(),
  67        __sz, _LT_pointer_compare());
  68
  69     if (__temp == _S_free_list.end() || !_M_should_i_give(**__temp, __sz))
  70       {
  71         // We release the lock here, because operator new is
  72         // guaranteed to be thread-safe by the underlying
  73         // implementation.
  74 #if defined __GTHREADS
  75         __bfl_lock._M_unlock();
  76 #endif
  77         // Try twice to get the memory: once directly, and the 2nd
  78         // time after clearing the free list. If both fail, then
  79         // throw std::bad_alloc().
  80         int __ctr = 2;
  81         while (__ctr)
  82           {
  83             size_t* __ret = 0;
  84             --__ctr;
  85             try
  86               {
  87                 __ret = reinterpret_cast<size_t*>
  88                   (::operator new(__sz + sizeof(size_t)));
  89               }
  90             catch(...)
  91               {
  92                 this->_M_clear();
  93               }
  94             if (!__ret)
  95               continue;
  96             *__ret = __sz;
  97             return __ret + 1;
  98           }
  99         throw std::bad_alloc();
 100       }
 101     else
 102       {
 103         size_t* __ret = *__temp;
 104         _S_free_list.erase(__temp);
 105 #if defined __GTHREADS
 106         __bfl_lock._M_unlock();
 107 #endif
 108         return __ret + 1;
 109       }
 110   }
 111
 112   void
 113   free_list::
 114   _M_clear()
 115   {
 116 #if defined __GTHREADS
 117     _Auto_Lock __bfl_lock(&_S_bfl_mutex);
 118 #endif
 119     iterator __iter = _S_free_list.begin();
 120     while (__iter != _S_free_list.end())
 121       {
 122         ::operator delete((void*)*__iter);
 123         ++__iter;
 124       }
 125     _S_free_list.clear();
 126   }
 127
 128   // Instantiations.
 129   template class bitmap_allocator<char>;
 130   template class bitmap_allocator<wchar_t>;
 131 } // namespace __gnu_cxx