meta_logger_impl.hpp

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/*
 * Copyright (c) 2014-2015, Hewlett-Packard Development Company, LP.
 * This program 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 of the License, or (at your option)
 * any later version.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * HP designates this particular file as subject to the "Classpath" exception
 * as provided by HP in the LICENSE.txt file that accompanied this code.
 */
#ifndef FOEDUS_LOG_META_LOGGER_IMPL_HPP_
#define FOEDUS_LOG_META_LOGGER_IMPL_HPP_
#include <stdint.h>

#include <atomic>
#include <iosfwd>
#include <thread>

#include "foedus/epoch.hpp"
#include "foedus/fwd.hpp"
#include "foedus/initializable.hpp"
#include "foedus/fs/fwd.hpp"
#include "foedus/log/fwd.hpp"
#include "foedus/log/log_id.hpp"
#include "foedus/log/meta_log_buffer.hpp"
#include "foedus/memory/aligned_memory.hpp"
#include "foedus/soc/shared_memory_repo.hpp"

namespace foedus {
namespace log {

class MetaLogger final : public DefaultInitializable {
 public:
  explicit MetaLogger(Engine* engine) : engine_(engine), control_block_(nullptr) {}
  ErrorStack  initialize_once() override;
  ErrorStack  uninitialize_once() override;

  MetaLogger() = delete;
  MetaLogger(const MetaLogger &other) = delete;
  MetaLogger& operator=(const MetaLogger &other) = delete;

  friend std::ostream&    operator<<(std::ostream& o, const MetaLogger& v);

 private:
  void        meta_logger_main();

  ErrorStack  switch_file_if_required();

  ErrorStack  log_epoch_switch(Epoch new_epoch);

  ErrorStack  truncate_non_durable(Epoch saved_durable_epoch);

  Engine* const               engine_;
  MetaLogControlBlock*        control_block_;
  std::thread                 logger_thread_;
  std::atomic<bool>           stop_requested_;
  fs::DirectIoFile*           current_file_;
};
static_assert(
  sizeof(MetaLogControlBlock) <= soc::GlobalMemoryAnchors::kMetaLoggerSize,
  "MetaLogControlBlock is too large.");
}  // namespace log
}  // namespace foedus
#endif  // FOEDUS_LOG_META_LOGGER_IMPL_HPP_