//=============================================================================
/**
 *  @file    allocator.cpp
 *
 * Compares the performance of a TSS allocator, with no locks, to
 * the global allocator (with locks) even in the abscence of
 * contention.
 * The idea behind this test is to measure the predictability of
 * each allocator, specially under the light of potential
 * fragmentation in the main allocator.
 *
 *  @author Carlos O'Ryan
 */
//=============================================================================


#include "tao/ORB_Core.h"
#include "tao/ORB.h"

#include "ace/Get_Opt.h"
#include "ace/High_Res_Timer.h"

#define DEFAULT_BUFFER_SIZE 512

/**
 * @class Application_Simulator
 *
 * Tries to simulate the behavior of an application: it randomly
 * acquires and releases memory, of variable sizes.
 * The intention is to produce some level of fragmentation in main
 * memory.
 */
class Application_Simulator
{
public:
  /// Constructor, limits the amount of fragmentation and memory this
  /// class takes.
  Application_Simulator (int max_fragments,
                    int max_fragment_size);

  /// Destructor, releases any memory left behind.
  ~Application_Simulator ();

  /**
   * Simulate an upcall. The class allocates some memory and then
   * releases some memory too, the amount of memory allocated and the
   * number of allocations is random.
   */
  void upcall (unsigned int* seed);

private:
  /// The allocated buffers.
  char** buffers_;

  /// The size of the <buffers_> array.
  int max_fragments_;

  /// The maximum size of any element of <buffers_>
  int max_fragment_size_;
};

int
ACE_TMAIN(int argc, ACE_TCHAR *argv[])
{
  try
    {
      CORBA::ORB_var orb =
        CORBA::ORB_init (argc, argv);

      int tss = 0;
      int iterations = 500;
      int repeat = 100;
      int max_fragments = 2048;
      int max_fragment_size = 1024;
      int max_arguments = 16;
      int max_argument_size = 1024;
      int quiet = 0;
      unsigned int seed = static_cast<unsigned int> (ACE_OS::time(0));

      ACE_Get_Opt get_opt (argc, argv, ACE_TEXT("tn:f:m:s:a:b:r:q"));
      int opt;

      while ((opt = get_opt ()) != EOF)
        {
          switch (opt)
            {
            case 't':
              tss = 1;
              break;
            case 'n':
              iterations = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'r':
              repeat = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'f':
              max_fragments = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'm':
              max_fragment_size = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 's':
              seed = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'a':
              max_arguments = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'b':
              max_argument_size = ACE_OS::atoi (get_opt.opt_arg ());
              break;
            case 'q':
              quiet = 1;
              break;
            case '?':
            default:
              ACE_DEBUG ((LM_DEBUG,
                          "Usage: %s "
                          "-n iterations "
                          "-n repeat "
                          "-f max_fragments "
                          "-m max_fragment_size "
                          "-s seed "
                          "-a max_arguments "
                          "-b max_argument_size "
                          "\n",
                          argv[0]));
              return -1;
            }
        }

      ACE_DEBUG ((LM_DEBUG, "SEED = %d\n", seed));

      ACE_Allocator* buffer_allocator =
        ACE_Allocator::instance ();
      ACE_Allocator* dblock_allocator =
        ACE_Allocator::instance ();
      if (tss)
        {
          buffer_allocator =
            TAO_ORB_Core_instance ()->output_cdr_buffer_allocator ();
          dblock_allocator =
            TAO_ORB_Core_instance ()->output_cdr_dblock_allocator ();
        }

      Application_Simulator simulator (max_fragments,
                                      max_fragment_size);
      char* argument_buffer;
      ACE_NEW_RETURN (argument_buffer, char[max_argument_size], 1);

      int* argument_sizes;
      ACE_NEW_RETURN (argument_sizes, int[max_arguments], 1);

      int n = ACE_OS::rand_r (&seed) % max_arguments + 1;
      for (int k = 0; k < n; ++k)
        argument_sizes[k] = ACE_OS::rand_r (&seed) % max_argument_size + 1;

      for (int i = 0; i < iterations; ++i)
        {
          simulator.upcall (&seed);

          // @@ TODO this is the place to put the other allocators.
          ACE_High_Res_Timer cdr_encoding;
          for (int j = 0; j < repeat; ++j)
            {
              cdr_encoding.start_incr ();

              char buffer[DEFAULT_BUFFER_SIZE];
              ACE_OutputCDR cdr (buffer, sizeof(buffer),
                                TAO_ENCAP_BYTE_ORDER,
                                buffer_allocator,
                                dblock_allocator);

              for (int k = 0; k < n; ++k)
                {
                  cdr.write_char_array (argument_buffer,
                                        argument_sizes[k]);
                }

              cdr_encoding.stop_incr ();
            }

          ACE_Time_Value tv;
          cdr_encoding.elapsed_time_incr (tv);
          ACE_hrtime_t usecs = tv.sec ();
          usecs *= static_cast<ACE_UINT32> (ACE_ONE_SECOND_IN_USECS);
          usecs += tv.usec ();
          double average =
            static_cast<double> (ACE_HRTIME_CONVERSION(usecs)) / repeat;

          if (!quiet)
            ACE_OS::printf ("AVE: %d %f\n",
                            i, average);
        }
    }
  catch (const CORBA::Exception& ex)
    {
      ex._tao_print_exception ("Caught unexpected CORBA exception:");

      return 1;
    }
  return 0;
}

Application_Simulator::Application_Simulator (int max_fragments,
                                    int max_fragment_size)
  :  max_fragments_ (max_fragments),
     max_fragment_size_ (max_fragment_size)
{
  ACE_NEW (buffers_, char*[this->max_fragments_]);
  for (char** i = this->buffers_;
       i != this->buffers_ + this->max_fragments_;
       ++i)
    *i = 0;
}

Application_Simulator::~Application_Simulator ()
{
  for (char** i = this->buffers_;
       i != this->buffers_ + this->max_fragments_;
       ++i)
    {
      if (*i != 0)
        {
          delete[] *i;
          *i = 0;
        }
    }
  delete[] this->buffers_;
  this->buffers_ = 0;
}

void
Application_Simulator::upcall (unsigned int* seed)
{
  for (char** i = this->buffers_;
       i != this->buffers_ + this->max_fragments_;
       ++i)
    {
      if (*i != 0)
        {
          if (ACE_OS::rand_r (seed) % 10000 < 5000)
            {
              delete[] *i;
              *i = 0;
            }
        }
      else
        {
          if (ACE_OS::rand_r (seed) % 10000 < 5000)
            {
              int size = ACE_OS::rand_r (seed) %
                this->max_fragment_size_ + 1;
              ACE_NEW (*i, char[size]);
            }
        }
    }
}