path: root/storage/perfschema/table_sync_instances.cc

/* Copyright (c) 2008, 2023, 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 also distributed 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 included with MySQL.

  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,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */

/**
  @file storage/perfschema/table_sync_instances.cc
  Table MUTEX_INSTANCES, RWLOCK_INSTANCES
  and COND_INSTANCES (implementation).
*/

#include "my_global.h"
#include "my_thread.h"
#include "pfs_instr.h"
#include "pfs_column_types.h"
#include "pfs_column_values.h"
#include "table_sync_instances.h"
#include "pfs_global.h"
#include "pfs_buffer_container.h"
#include "field.h"

THR_LOCK table_mutex_instances::m_table_lock;

PFS_engine_table_share_state
table_mutex_instances::m_share_state = {
  false /* m_checked */
};

PFS_engine_table_share
table_mutex_instances::m_share=
{
  { C_STRING_WITH_LEN("mutex_instances") },
  &pfs_readonly_acl,
  table_mutex_instances::create,
  NULL, /* write_row */
  NULL, /* delete_all_rows */
  table_mutex_instances::get_row_count,
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE mutex_instances("
                      "NAME VARCHAR(128) not null comment 'Instrument name associated with the mutex.',"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Memory address of the instrumented mutex.',"
                      "LOCKED_BY_THREAD_ID BIGINT unsigned comment 'The THREAD_ID of the locking thread if a thread has a mutex locked, otherwise NULL.')") },
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

PFS_engine_table* table_mutex_instances::create(void)
{
  return new table_mutex_instances();
}

ha_rows
table_mutex_instances::get_row_count(void)
{
  return global_mutex_container.get_row_count();
}

table_mutex_instances::table_mutex_instances()
  : PFS_engine_table(&m_share, &m_pos),
  m_row_exists(false), m_pos(0), m_next_pos(0)
{}

void table_mutex_instances::reset_position(void)
{
  m_pos.m_index= 0;
  m_next_pos.m_index= 0;
}

int table_mutex_instances::rnd_next(void)
{
  PFS_mutex *pfs;

  m_pos.set_at(&m_next_pos);
  PFS_mutex_iterator it= global_mutex_container.iterate(m_pos.m_index);
  pfs= it.scan_next(& m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    m_next_pos.set_after(&m_pos);
    return 0;
  }

  return HA_ERR_END_OF_FILE;
}

int table_mutex_instances::rnd_pos(const void *pos)
{
  PFS_mutex *pfs;

  set_position(pos);

  pfs= global_mutex_container.get(m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_mutex_instances::make_row(PFS_mutex *pfs)
{
  pfs_optimistic_state lock;
  PFS_mutex_class *safe_class;

  m_row_exists= false;

  /* Protect this reader against a mutex destroy */
  pfs->m_lock.begin_optimistic_lock(&lock);

  safe_class= sanitize_mutex_class(pfs->m_class);
  if (unlikely(safe_class == NULL))
    return;

  m_row.m_name= safe_class->m_name;
  m_row.m_name_length= safe_class->m_name_length;
  m_row.m_identity= pfs->m_identity;

  /* Protect this reader against a mutex unlock */
  PFS_thread *safe_owner= sanitize_thread(pfs->m_owner);
  if (safe_owner)
  {
    m_row.m_locked_by_thread_id= safe_owner->m_thread_internal_id;
    m_row.m_locked= true;
  }
  else
    m_row.m_locked= false;

  if (pfs->m_lock.end_optimistic_lock(&lock))
    m_row_exists= true;
}

int table_mutex_instances::read_row_values(TABLE *table,
                                           unsigned char *buf,
                                           Field **fields,
                                           bool read_all)
{
  Field *f;

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  assert(table->s->null_bytes == 1);
  buf[0]= 0;

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* NAME */
        set_field_varchar_utf8(f, m_row.m_name, m_row.m_name_length);
        break;
      case 1: /* OBJECT_INSTANCE */
        set_field_ulonglong(f, (intptr) m_row.m_identity);
        break;
      case 2: /* LOCKED_BY_THREAD_ID */
        if (m_row.m_locked)
          set_field_ulonglong(f, m_row.m_locked_by_thread_id);
        else
          f->set_null();
        break;
      default:
        assert(false);
      }
    }
  }

  return 0;
}

THR_LOCK table_rwlock_instances::m_table_lock;

PFS_engine_table_share_state
table_rwlock_instances::m_share_state = {
  false /* m_checked */
};

PFS_engine_table_share
table_rwlock_instances::m_share=
{
  { C_STRING_WITH_LEN("rwlock_instances") },
  &pfs_readonly_acl,
  table_rwlock_instances::create,
  NULL, /* write_row */
  NULL, /* delete_all_rows */
  table_rwlock_instances::get_row_count,
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE rwlock_instances("
                      "NAME VARCHAR(128) not null comment 'Instrument name associated with the read write lock',"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the instrumented lock',"
                      "WRITE_LOCKED_BY_THREAD_ID BIGINT unsigned comment 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.',"
                      "READ_LOCKED_BY_COUNT INTEGER unsigned not null comment 'Count of current read locks held')") },
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

PFS_engine_table* table_rwlock_instances::create(void)
{
  return new table_rwlock_instances();
}

ha_rows
table_rwlock_instances::get_row_count(void)
{
  return global_rwlock_container.get_row_count();
}

table_rwlock_instances::table_rwlock_instances()
  : PFS_engine_table(&m_share, &m_pos),
  m_row_exists(false), m_pos(0), m_next_pos(0)
{}

void table_rwlock_instances::reset_position(void)
{
  m_pos.m_index= 0;
  m_next_pos.m_index= 0;
}

int table_rwlock_instances::rnd_next(void)
{
  PFS_rwlock *pfs;

  m_pos.set_at(&m_next_pos);
  PFS_rwlock_iterator it= global_rwlock_container.iterate(m_pos.m_index);
  pfs= it.scan_next(& m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    m_next_pos.set_after(&m_pos);
    return 0;
  }

  return HA_ERR_END_OF_FILE;
}

int table_rwlock_instances::rnd_pos(const void *pos)
{
  PFS_rwlock *pfs;

  set_position(pos);

  pfs= global_rwlock_container.get(m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_rwlock_instances::make_row(PFS_rwlock *pfs)
{
  pfs_optimistic_state lock;
  PFS_rwlock_class *safe_class;

  m_row_exists= false;

  /* Protect this reader against a rwlock destroy */
  pfs->m_lock.begin_optimistic_lock(&lock);

  safe_class= sanitize_rwlock_class(pfs->m_class);
  if (unlikely(safe_class == NULL))
    return;

  m_row.m_name= safe_class->m_name;
  m_row.m_name_length= safe_class->m_name_length;
  m_row.m_identity= pfs->m_identity;

  /* Protect this reader against a rwlock unlock in the writer */
  PFS_thread *safe_writer= sanitize_thread(pfs->m_writer);
  if (safe_writer)
  {
    m_row.m_write_locked_by_thread_id= safe_writer->m_thread_internal_id;
    m_row.m_readers= 0;
    m_row.m_write_locked= true;
  }
  else
  {
    m_row.m_readers= pfs->m_readers;
    m_row.m_write_locked= false;
  }

  if (pfs->m_lock.end_optimistic_lock(&lock))
    m_row_exists= true;
}

int table_rwlock_instances::read_row_values(TABLE *table,
                                             unsigned char *buf,
                                             Field **fields,
                                             bool read_all)
{
  Field *f;

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  assert(table->s->null_bytes == 1);
  buf[0]= 0;

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* NAME */
        set_field_varchar_utf8(f, m_row.m_name, m_row.m_name_length);
        break;
      case 1: /* OBJECT_INSTANCE */
        set_field_ulonglong(f, (intptr) m_row.m_identity);
        break;
      case 2: /* WRITE_LOCKED_BY_THREAD_ID */
        if (m_row.m_write_locked)
          set_field_ulonglong(f, m_row.m_write_locked_by_thread_id);
        else
          f->set_null();
        break;
      case 3: /* READ_LOCKED_BY_COUNT */
        set_field_ulong(f, m_row.m_readers);
        break;
      default:
        assert(false);
      }
    }
  }

  return 0;
}

THR_LOCK table_cond_instances::m_table_lock;

PFS_engine_table_share_state
table_cond_instances::m_share_state = {
  false /* m_checked */
};

PFS_engine_table_share
table_cond_instances::m_share=
{
  { C_STRING_WITH_LEN("cond_instances") },
  &pfs_readonly_acl,
  table_cond_instances::create,
  NULL, /* write_row */
  NULL, /* delete_all_rows */
  table_cond_instances::get_row_count,
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE cond_instances("
                      "NAME VARCHAR(128) not null comment 'Client user name for the connection, or NULL if an internal thread.',"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the instrumented condition.')") },
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

PFS_engine_table* table_cond_instances::create(void)
{
  return new table_cond_instances();
}

ha_rows
table_cond_instances::get_row_count(void)
{
  return global_cond_container.get_row_count();
}

table_cond_instances::table_cond_instances()
  : PFS_engine_table(&m_share, &m_pos),
  m_row_exists(false), m_pos(0), m_next_pos(0)
{}

void table_cond_instances::reset_position(void)
{
  m_pos.m_index= 0;
  m_next_pos.m_index= 0;
}

int table_cond_instances::rnd_next(void)
{
  PFS_cond *pfs;

  m_pos.set_at(&m_next_pos);
  PFS_cond_iterator it= global_cond_container.iterate(m_pos.m_index);
  pfs= it.scan_next(& m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    m_next_pos.set_after(&m_pos);
    return 0;
  }

  return HA_ERR_END_OF_FILE;
}

int table_cond_instances::rnd_pos(const void *pos)
{
  PFS_cond *pfs;

  set_position(pos);

  pfs= global_cond_container.get(m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_cond_instances::make_row(PFS_cond *pfs)
{
  pfs_optimistic_state lock;
  PFS_cond_class *safe_class;

  m_row_exists= false;

  /* Protect this reader against a cond destroy */
  pfs->m_lock.begin_optimistic_lock(&lock);

  safe_class= sanitize_cond_class(pfs->m_class);
  if (unlikely(safe_class == NULL))
    return;

  m_row.m_name= safe_class->m_name;
  m_row.m_name_length= safe_class->m_name_length;
  m_row.m_identity= pfs->m_identity;

  if (pfs->m_lock.end_optimistic_lock(&lock))
    m_row_exists= true;
}

int table_cond_instances::read_row_values(TABLE *table,
                                          unsigned char *,
                                          Field **fields,
                                          bool read_all)
{
  Field *f;

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  assert(table->s->null_bytes == 0);

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* NAME */
        set_field_varchar_utf8(f, m_row.m_name, m_row.m_name_length);
        break;
      case 1: /* OBJECT_INSTANCE */
        set_field_ulonglong(f, (intptr) m_row.m_identity);
        break;
      default:
        assert(false);
      }
    }
  }

  return 0;
}