lockfree_transaction_table.cpp

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/*
 * Copyright 2008 Search Solution Corporation
 * Copyright 2016 CUBRID Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

#include "lockfree_transaction_table.hpp"

#include "lockfree_bitmap.hpp"
#include "lockfree_transaction_descriptor.hpp"
#include "lockfree_transaction_system.hpp"

#include <cassert>

namespace lockfree
{
  namespace tran
  {
    //
    // table
    //
    table::table (system &sys)
      : m_sys (sys)
      , m_all (new descriptor[m_sys.get_max_transaction_count ()] ())
      , m_global_tranid { 0 }
      , m_min_active_tranid { 0 }
    {
      for (size_t i = 0; i < m_sys.get_max_transaction_count (); i++)
    {
      m_all[i].set_table (*this);
    }
    }

    table::~table ()
    {
      delete [] m_all;
    }

    descriptor &
    table::get_descriptor (const index &tran_index)
    {
      assert (tran_index <= m_sys.get_max_transaction_count ());
      return m_all[tran_index];
    }

    void
    table::start_tran (const index &tran_index)
    {
      get_descriptor (tran_index).start_tran ();
    }

    void
    table::end_tran (const index &tran_index)
    {
      get_descriptor (tran_index).end_tran ();
    }

    id
    table::get_new_global_tranid ()
    {
      id ret = ++m_global_tranid;
      if (ret % MATI_REFRESH_INTERVAL == 0)
    {
      compute_min_active_tranid ();
    }
      return ret;
    }

    id
    table::get_current_global_tranid () const
    {
      return m_global_tranid;
    }

    void
    table::compute_min_active_tranid ()
    {
      // note: all transactions are actually claimed from boot. this code is optimized for this case. if we ever
      //       change how transactions are requested, this must be updated too
      id minvalue = INVALID_TRANID;  // nothing is bigger than INVALID_TRANID
      for (size_t it = 0; it < m_sys.get_max_transaction_count (); it++)
    {
      id tranid = m_all[it].get_transaction_id ();
      if (minvalue > tranid)
        {
          minvalue = tranid;
        }
    }
      m_min_active_tranid.store (minvalue);
    }

    id
    table::get_min_active_tranid () const
    {
      return m_min_active_tranid;
    }

    size_t
    table::get_total_retire_count () const
    {
      size_t total = 0;
      for (size_t idx = 0; idx < m_sys.get_max_transaction_count (); idx++)
    {
      total += m_all[idx].get_total_retire_count ();
    }
      return total;
    }

    size_t
    table::get_total_reclaim_count () const
    {
      size_t total = 0;
      for (size_t idx = 0; idx < m_sys.get_max_transaction_count (); idx++)
    {
      total += m_all[idx].get_total_reclaim_count ();
    }
      return total;
    }

    size_t
    table::get_current_retire_count () const
    {
      size_t total = 0;
      for (size_t idx = 0; idx < m_sys.get_max_transaction_count (); idx++)
    {
      total += m_all[idx].get_current_retire_count ();
    }
      return total;
    }
  } // namespace tran
} // namespace lockfree