libstdc++-v3/include/ext/throw_allocator.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007 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 terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19 // MA 02111-1307, USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
  36 // and this permission notice appear in supporting documentation. None
  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
  39 // purpose. It is provided "as is" without express or implied
  40 // warranty.
  41
  42 /** @file ext/vstring.h
  43  *  This file is a GNU extension to the Standard C++ Library.
  44  *
  45  *  Contains an exception-throwing allocator, useful for testing
  46  *  exception safety. In addition, allocation addresses are stored and
  47  *  sanity checked.
  48  */
  49
  50 /**
  51  * @file throw_allocator.h
  52  */
  53
  54 #ifndef _THROW_ALLOCATOR_H
  55 #define _THROW_ALLOCATOR_H 1
  56
  57 #include <cmath>
  58 #include <ctime>
  59 #include <map>
  60 #include <set>
  61 #include <string>
  62 #include <ostream>
  63 #include <stdexcept>
  64 #include <utility>
  65 #include <tr1/random>
  66
  67 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  68
  69   class twister_rand_gen
  70   {
  71   public:
  72     twister_rand_gen(unsigned int seed =
  73                      static_cast<unsigned int>(std::time(0)));
  74
  75     void
  76     init(unsigned int);
  77
  78     double
  79     get_prob();
  80
  81   private:
  82     std::tr1::mt19937 _M_generator;
  83   };
  84
  85
  86   struct forced_exception_error : public std::exception
  87   { };
  88
  89   class throw_allocator_base
  90   {
  91   public:
  92     void
  93     init(unsigned long seed);
  94
  95     static void
  96     set_throw_prob(double throw_prob);
  97
  98     static double
  99     get_throw_prob();
 100
 101     static void
 102     set_label(size_t l);
 103
 104     static bool
 105     empty();
 106
 107     struct group_throw_prob_adjustor
 108     {
 109       group_throw_prob_adjustor(size_t size)
 110       : _M_throw_prob_orig(_S_throw_prob)
 111       {
 112         _S_throw_prob =
 113           1 - std::pow(double(1 - _S_throw_prob), double(0.5 / (size + 1)));
 114       }
 115
 116       ~group_throw_prob_adjustor()
 117       { _S_throw_prob = _M_throw_prob_orig; }
 118
 119     private:
 120       const double _M_throw_prob_orig;
 121     };
 122
 123     struct zero_throw_prob_adjustor
 124     {
 125       zero_throw_prob_adjustor() : _M_throw_prob_orig(_S_throw_prob)
 126       { _S_throw_prob = 0; }
 127
 128       ~zero_throw_prob_adjustor()
 129       { _S_throw_prob = _M_throw_prob_orig; }
 130
 131     private:
 132       const double _M_throw_prob_orig;
 133     };
 134
 135   protected:
 136     static void
 137     insert(void*, size_t);
 138
 139     static void
 140     erase(void*, size_t);
 141
 142     static void
 143     throw_conditionally();
 144
 145     // See if a particular address and size has been allocated by this
 146     // allocator.
 147     static void
 148     check_allocated(void*, size_t);
 149
 150     // See if a given label has been allocated by this allocator.
 151     static void
 152     check_allocated(size_t);
 153
 154   private:
 155     typedef std::pair<size_t, size_t>           alloc_data_type;
 156     typedef std::map<void*, alloc_data_type>    map_type;
 157     typedef map_type::value_type                entry_type;
 158     typedef map_type::const_iterator            const_iterator;
 159     typedef map_type::const_reference           const_reference;
 160
 161     friend std::ostream&
 162     operator<<(std::ostream&, const throw_allocator_base&);
 163
 164     static entry_type
 165     make_entry(void*, size_t);
 166
 167     static void
 168     print_to_string(std::string&);
 169
 170     static void
 171     print_to_string(std::string&, const_reference);
 172
 173     static twister_rand_gen     _S_g;
 174     static map_type             _S_map;
 175     static double               _S_throw_prob;
 176     static size_t               _S_label;
 177   };
 178
 179
 180   template<typename T>
 181     class throw_allocator : public throw_allocator_base
 182     {
 183     public:
 184       typedef size_t                            size_type;
 185       typedef ptrdiff_t                         difference_type;
 186       typedef T                                 value_type;
 187       typedef value_type*                       pointer;
 188       typedef const value_type*                 const_pointer;
 189       typedef value_type&                       reference;
 190       typedef const value_type&                 const_reference;
 191
 192
 193       template<typename U>
 194       struct rebind
 195       {
 196         typedef throw_allocator<U> other;
 197       };
 198
 199       throw_allocator() throw() { }
 200
 201       throw_allocator(const throw_allocator&) throw() { }
 202
 203       template<typename U>
 204       throw_allocator(const throw_allocator<U>&) throw() { }
 205
 206       ~throw_allocator() throw() { }
 207
 208       size_type
 209       max_size() const throw()
 210       { return std::allocator<value_type>().max_size(); }
 211
 212       pointer
 213       allocate(size_type num, std::allocator<void>::const_pointer hint = 0)
 214       {
 215         throw_conditionally();
 216         value_type* const a = std::allocator<value_type>().allocate(num, hint);
 217         insert(a, sizeof(value_type) * num);
 218         return a;
 219       }
 220
 221       void
 222       construct(pointer p, const T& val)
 223       { return std::allocator<value_type>().construct(p, val); }
 224
 225       void
 226       destroy(pointer p)
 227       { std::allocator<value_type>().destroy(p); }
 228
 229       void
 230       deallocate(pointer p, size_type num)
 231       {
 232         erase(p, sizeof(value_type) * num);
 233         std::allocator<value_type>().deallocate(p, num);
 234       }
 235
 236       void
 237       check_allocated(pointer p, size_type num)
 238       { throw_allocator_base::check_allocated(p, sizeof(value_type) * num); }
 239
 240       void
 241       check_allocated(size_type label)
 242       { throw_allocator_base::check_allocated(label); }
 243     };
 244
 245   template<typename T>
 246     inline bool
 247     operator==(const throw_allocator<T>&, const throw_allocator<T>&)
 248     { return true; }
 249
 250   template<typename T>
 251     inline bool
 252     operator!=(const throw_allocator<T>&, const throw_allocator<T>&)
 253     { return false; }
 254
 255   std::ostream&
 256   operator<<(std::ostream& os, const throw_allocator_base& alloc)
 257   {
 258     std::string error;
 259     throw_allocator_base::print_to_string(error);
 260     os << error;
 261     return os;
 262   }
 263
 264   // XXX Should be in .cc.
 265   twister_rand_gen::
 266   twister_rand_gen(unsigned int seed) : _M_generator(seed)  { }
 267
 268   void
 269   twister_rand_gen::
 270   init(unsigned int seed)
 271   { _M_generator.seed(seed); }
 272
 273   double
 274   twister_rand_gen::
 275   get_prob()
 276   {
 277     const double eng_min = _M_generator.min();
 278     const double eng_range =
 279       static_cast<const double>(_M_generator.max() - eng_min);
 280
 281     const double eng_res =
 282       static_cast<const double>(_M_generator() - eng_min);
 283
 284     const double ret = eng_res / eng_range;
 285     _GLIBCXX_DEBUG_ASSERT(ret >= 0 && ret <= 1);
 286     return ret;
 287   }
 288
 289   twister_rand_gen throw_allocator_base::_S_g;
 290
 291   throw_allocator_base::map_type
 292   throw_allocator_base::_S_map;
 293
 294   double throw_allocator_base::_S_throw_prob;
 295
 296   size_t throw_allocator_base::_S_label = 0;
 297
 298   throw_allocator_base::entry_type
 299   throw_allocator_base::make_entry(void* p, size_t size)
 300   { return std::make_pair(p, alloc_data_type(_S_label, size)); }
 301
 302   void
 303   throw_allocator_base::init(unsigned long seed)
 304   { _S_g.init(seed); }
 305
 306   void
 307   throw_allocator_base::set_throw_prob(double throw_prob)
 308   { _S_throw_prob = throw_prob; }
 309
 310   double
 311   throw_allocator_base::get_throw_prob()
 312   { return _S_throw_prob; }
 313
 314   void
 315   throw_allocator_base::set_label(size_t l)
 316   { _S_label = l; }
 317
 318   void
 319   throw_allocator_base::insert(void* p, size_t size)
 320   {
 321     const_iterator found_it = _S_map.find(p);
 322     if (found_it != _S_map.end())
 323       {
 324         std::string error("throw_allocator_base::insert");
 325         error += "double insert!";
 326         error += '\n';
 327         print_to_string(error, make_entry(p, size));
 328         print_to_string(error, *found_it);
 329         throw std::logic_error(error);
 330       }
 331     _S_map.insert(make_entry(p, size));
 332   }
 333
 334   bool
 335   throw_allocator_base::empty()
 336   { return _S_map.empty(); }
 337
 338   void
 339   throw_allocator_base::erase(void* p, size_t size)
 340   {
 341     check_allocated(p, size);
 342     _S_map.erase(p);
 343   }
 344
 345   void
 346   throw_allocator_base::check_allocated(void* p, size_t size)
 347   {
 348     const_iterator found_it = _S_map.find(p);
 349     if (found_it == _S_map.end())
 350       {
 351         std::string error("throw_allocator_base::check_allocated by value ");
 352         error += "null erase!";
 353         error += '\n';
 354         print_to_string(error, make_entry(p, size));
 355         throw std::logic_error(error);
 356       }
 357
 358     if (found_it->second.second != size)
 359       {
 360         std::string error("throw_allocator_base::check_allocated by value ");
 361         error += "wrong-size erase!";
 362         error += '\n';
 363         print_to_string(error, make_entry(p, size));
 364         print_to_string(error, *found_it);
 365         throw std::logic_error(error);
 366       }
 367   }
 368
 369   void
 370   throw_allocator_base::check_allocated(size_t label)
 371   {
 372     std::string found;
 373     const_iterator it = _S_map.begin();
 374     while (it != _S_map.end())
 375       {
 376         if (it->second.first == label)
 377           print_to_string(found, *it);
 378         ++it;
 379       }
 380
 381     if (!found.empty())
 382       {
 383         std::string error("throw_allocator_base::check_allocated by label ");
 384         error += '\n';
 385         error += found;
 386         throw std::logic_error(error);
 387       }
 388   }
 389
 390   void
 391   throw_allocator_base::throw_conditionally()
 392   {
 393     if (_S_g.get_prob() < _S_throw_prob)
 394       throw forced_exception_error();
 395   }
 396
 397   void
 398   throw_allocator_base::print_to_string(std::string& s)
 399   {
 400     const_iterator begin = throw_allocator_base::_S_map.begin();
 401     const_iterator end = throw_allocator_base::_S_map.end();
 402     for (; begin != end; ++begin)
 403       print_to_string(s, *begin);
 404   }
 405
 406   void
 407   throw_allocator_base::print_to_string(std::string& s, const_reference ref)
 408   {
 409     char buf[40];
 410     const char tab('\t');
 411     s += "address: ";
 412     sprintf(buf, "%p", ref.first);
 413     s += buf;
 414     s += tab;
 415     s += "label: ";
 416     sprintf(buf, "%u", ref.second.first);
 417     s += buf;
 418     s += tab;
 419     s += "size: ";
 420     sprintf(buf, "%u", ref.second.second);
 421     s += buf;
 422     s += '\n';
 423   }
 424
 425 _GLIBCXX_END_NAMESPACE
 426
 427 #endif