Please could you run this test on your machine?

[Dhruv Matani <dhruvbird at gmx dot net>]

I would like to know the result of this test on Machines with multiple
CPU's as well as a single CPU. I would expect this test to do well in a
single CPU environment, but test results may not agree with me. This
test actually emulates a real world app.

You can leave out testing bitmap_allocator for now.

I am interested in knowing the cache performance of the default alloctor
v/s the __mt_alloc mainly.

On my single CPU Duron 1GHz, 640MB DDR SD RAM, the results are like
this:


//__mt_alloc.
[dhruv@localhost test]$ compile map_test.cpp v4 -lpthread -O3
The Compiler command passed is: g++34 -Wall -lpthread -O3 -o map_test
map_test.cpp
[dhruv@localhost test]$ time ./map_test
Size of Map is: 20
Time taken to Insert: 4.82 Seconds.
Time taken to Find: 0 Seconds.
Time taken to Clear: 1.07 Seconds.
Time taken to Insert: 6.12 Seconds.
Time taken to Find: 0 Seconds.
Time taken to Clear: 1.16 Seconds.

real    1m23.004s
user    1m22.730s
sys     0m0.110s


//std::allocator, which AFAICS is currently new_allocator.
[dhruv@localhost test]$ compile map_test.cpp v4 -lpthread -O3
The Compiler command passed is: g++34 -Wall -lpthread -O3 -o map_test
map_test.cpp
[dhruv@localhost test]$ time ./map_test
Size of Map is: 20
Time taken to Insert: 4.61 Seconds.
Time taken to Find: 0 Seconds.
Time taken to Clear: 0.62 Seconds.
Time taken to Insert: 5.91 Seconds.
Time taken to Find: 0 Seconds.
Time taken to Clear: 0.62 Seconds.

real    1m19.806s
user    1m19.340s
sys     0m0.220s
[dhruv@localhost test]$ 





-- 
	-Dhruv Matani.
http://www.geocities.com/dhruvbird/

Proud to be a Vegetarian.
http://www.vegetarianstarterkit.com/
http://www.vegkids.com/vegkids/index.html

#include <new>
#include <iostream>
#include <nstl/timer.hpp>
#include <map>
#include <ext/bitmap_allocator.h>
#include <ext/mt_allocator.h>
#include <cstdlib>
#include <string>
#include <pthread.h>

using namespace __gnu_cxx;
using namespace std;

bool less_int (int x1, int x2) { return x1<x2; }

//#define USE_FUNCTION_COMPARE
//#define USE_BITMAP_ALLOCATOR
//#define USE_MT_ALLOCATOR

#if defined USE_FUNCTION_COMPARE
#define COMPARE_T typeof(&less_int)
#define COMPARE_F &less_int
#else
#define COMPARE_T std::less<int>
#define COMPARE_F std::less<int>()
#endif

#if defined USE_BITMAP_ALLOCATOR
#define MAP_ALLOC bitmap_allocator<int>
#else
  #if defined USE_MT_ALLOCATOR
  #define MAP_ALLOC __mt_alloc<int>
  #else
  #define MAP_ALLOC std::allocator<int>
  #endif
#endif

void *find_proc (void *_vptr)
{
  map<int, string, COMPARE_T, MAP_ALLOC> *_mptr = 
    reinterpret_cast<map<int, string, COMPARE_T, MAP_ALLOC>*>(_vptr);

  for (int i = 0; i < 3000000; ++i)
    _mptr->find (rand() % 2000000);
  return _vptr;
}


int main()
{
  COMPARE_T _comp = COMPARE_F;

  map<int, string, COMPARE_T, MAP_ALLOC> imap (_comp);
  nstd::timer t;
  pthread_t thr[3];

  cout<<"Size of Map is: "<<sizeof(imap)<<endl;
  int x = 2;

  while (x--)
    {
      t.start();
      for (int i = 0; i < 1000000; ++i)
	imap.insert (make_pair (rand()%1000000, "_test_data"));

      for (int i = 0; i < 100000; ++i)
	imap.insert (make_pair (rand()%2000000, "_test_data"));
      t.stop();

      cout<<"Time taken to Insert: "<<t()<<" Seconds."<<endl;

      t.start();
      pthread_create (&thr[0], NULL, find_proc, (void*)&imap);
      pthread_create (&thr[1], NULL, find_proc, (void*)&imap);
      pthread_create (&thr[2], NULL, find_proc, (void*)&imap);

      pthread_join (thr[0], 0);
      pthread_join (thr[1], 0);
      pthread_join (thr[2], 0);

      t.stop();

      cout<<"Time taken to Find: "<<t()<<" Seconds."<<endl;


      t.start();
      imap.clear ();
      t.stop();

      cout<<"Time taken to Clear: "<<t()<<" Seconds."<<endl;
    }

//   int temp;
//   cin>>temp;
}