table_data_locks.h

Go to the documentation of this file.

/* Copyright (c) 2016, 2025, Oracle and/or its affiliates.
 
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
  This program is designed to work with certain software (including
  but not limited to OpenSSL) that is licensed under separate terms,
  as designated in a particular file or component or in included license
  documentation.  The authors of MySQL hereby grant you an additional
  permission to link the program and your derivative works with the
  separately licensed software that they have either included with
  the program or referenced in the documentation.
 
  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, version 2.0, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef TABLE_DATA_LOCK_H
#define TABLE_DATA_LOCK_H
 
/**
  @file storage/perfschema/table_data_locks.h
  Table DATA_LOCKS (declarations).
*/
 
#include <sys/types.h>
 
#include "my_base.h"
#include "storage/perfschema/pfs.h"
#include "storage/perfschema/pfs_data_lock.h"
#include "storage/perfschema/pfs_engine_table.h"
 
class Field;
class PSI_engine_data_lock_iterator;
class Plugin_table;
struct TABLE;
struct THR_LOCK;
 
/**
  @addtogroup Performance_schema_tables
  @{
*/
 
/**
  Position of a cursor on
  PERFORMANCE_SCHEMA.DATA_LOCKS.
  Index 1 on engine (0 based)
  Index 2 on engine index (0 based)
*/
struct scan_pos_data_lock {
  scan_pos_data_lock() {
    m_index_1 = 0;
    m_index_2 = 0;
  }
 
  inline void reset() {
    m_index_1 = 0;
    m_index_2 = 0;
  }
 
  void set_at(const scan_pos_data_lock *other) {
    m_index_1 = other->m_index_1;
    m_index_2 = other->m_index_2;
  }
 
  void set_after(const scan_pos_data_lock *other) {
    m_index_1 = other->m_index_1;
    m_index_2 = other->m_index_2 + 1;
  }
 
  inline bool has_more_engine() const {
    return (m_index_1 < COUNT_DATA_LOCK_ENGINES);
  }
 
  inline void next_engine() {
    m_index_1++;
    m_index_2 = 0;
  }
 
  unsigned int m_index_1;
  unsigned int m_index_2;
};
 
/** Table PERFORMANCE_SCHEMA.DATA_LOCKS. */
class table_data_locks : public PFS_engine_table {
  typedef scan_pos_data_lock scan_pos_t;
  typedef pk_pos_data_lock pk_pos_t;
 
 public:
  /** Table share. */
  static PFS_engine_table_share m_share;
  static PFS_engine_table *create(PFS_engine_table_share *);
  static ha_rows get_row_count();
 
  int rnd_next() override;
  int rnd_pos(const void *pos) override;
  void reset_position() override;
 
  int index_init(uint idx, bool sorted) override;
  int index_next() override;
 
 private:
  int read_row_values(TABLE *table, unsigned char *buf, Field **fields,
                      bool read_all) override;
 
  table_data_locks();
 
  void destroy_iterators();
 
 public:
  ~table_data_locks() override;
 
 private:
  /** Table share lock. */
  static THR_LOCK m_table_lock;
  /** Table definition. */
  static Plugin_table m_table_def;
 
  /** Current row. */
  row_data_lock *m_row;
  /** Current scan position. */
  scan_pos_t m_pos;
  /** Next scan position. */
  scan_pos_t m_next_pos;
  /** Current pk position. */
  pk_pos_t m_pk_pos;
 
  PFS_data_lock_container m_container;
  PSI_engine_data_lock_iterator *m_iterator[COUNT_DATA_LOCK_ENGINES];
 
  PFS_pk_data_locks *m_opened_pk;
  PFS_index_data_locks *m_opened_index;
};
 
/** @} */
#endif