16728.cc

Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

// Copyright (C) 2004, 2005 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 * The goal with this application is to compare the performance
 * between different std::allocator implementations. The results are
 * influenced by the underlying allocator in the "C" library, malloc.
 */

#include <set>
#include <sstream>

using namespace std;

typedef int test_type;

// The number of iterations to be performed.
int iterations = 10000;

// The number of values to insert in the container, 32 will cause 5
// (re)allocations to be performed (sizes 4, 8, 16, 32 and 64)
// This means that all allocations are within _MAX_BYTES = 128 as
// defined in stl_alloc.h for __pool_alloc.  Whether or not this
// value is relevant in "the real world" or not I don't know and
// should probably be investigated in more detail.
int insert_values = 128;

template<typename TestType>
  struct value_type : public pair<TestType, TestType>
  {
    value_type() : pair<TestType, TestType>(0, 0) { }

    inline value_type operator++() { return ++this->first, *this; }
    inline operator TestType() const { return this->first; }
  };

template<typename Container>
  void
  do_loop()
  {
    Container obj;
    int test_iterations = 0;
    value_type<test_type> test_value;
    while (test_iterations < iterations)
      {
	for (int j = 0; j < insert_values; ++j)
	  obj.insert(obj.end(), ++test_value);
	++test_iterations;
      }
  }

template<typename Container>
  void
  test_container(Container obj, bool run_threaded = false)
  {
    do_loop<Container>();
    std::ostringstream comment;
    if (run_threaded)
      comment << "4-way threaded iterations: " << iterations*4 << '\t';
    else
      comment << "iterations: " << iterations << '\t';
  }

// http://gcc.gnu.org/ml/libstdc++/2001-05/msg00105.html
// http://gcc.gnu.org/ml/libstdc++/2003-05/msg00231.html
int main(void)
{
  typedef less<test_type> compare_type;
  test_container(set<test_type, compare_type>());
  return 0;
}