/* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.

  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; version 2 of the License.

  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,
  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_pthread.h"
#include "pfs_instr.h"
#include "pfs_column_types.h"
#include "pfs_column_values.h"
#include "table_sync_instances.h"
#include "pfs_global.h"

THR_LOCK table_mutex_instances::m_table_lock;

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 */
  NULL, /* get_row_count */
  1000, /* records */
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE mutex_instances("
                      "NAME VARCHAR(128) not null,"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
                      "LOCKED_BY_THREAD_ID BIGINT unsigned)") }
};

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

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;

  for (m_pos.set_at(&m_next_pos); m_pos.m_index < mutex_max; m_pos.next())
  {
    pfs= &mutex_array[m_pos.m_index];
    if (pfs->m_lock.is_populated())
    {
      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);
  DBUG_ASSERT(m_pos.m_index < mutex_max);
  pfs= &mutex_array[m_pos.m_index];
  if (pfs->m_lock.is_populated())
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_mutex_instances::make_row(PFS_mutex *pfs)
{
  pfs_lock 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 */
  DBUG_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:
        DBUG_ASSERT(false);
      }
    }
  }

  return 0;
}

THR_LOCK table_rwlock_instances::m_table_lock;

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 */
  NULL, /* get_row_count */
  1000, /* records */
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE rwlock_instances("
                      "NAME VARCHAR(128) not null,"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
                      "WRITE_LOCKED_BY_THREAD_ID BIGINT unsigned,"
                      "READ_LOCKED_BY_COUNT INTEGER unsigned not null)") }
};

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

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;

  for (m_pos.set_at(&m_next_pos); m_pos.m_index < rwlock_max; m_pos.next())
  {
    pfs= &rwlock_array[m_pos.m_index];
    if (pfs->m_lock.is_populated())
    {
      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);
  DBUG_ASSERT(m_pos.m_index < rwlock_max);
  pfs= &rwlock_array[m_pos.m_index];
  if (pfs->m_lock.is_populated())
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_rwlock_instances::make_row(PFS_rwlock *pfs)
{
  pfs_lock 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 */
  DBUG_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:
        DBUG_ASSERT(false);
      }
    }
  }

  return 0;
}

THR_LOCK table_cond_instances::m_table_lock;

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 */
  NULL, /* get_row_count */
  1000, /* records */
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE cond_instances("
                      "NAME VARCHAR(128) not null,"
                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null)") }
};

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

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;

  for (m_pos.set_at(&m_next_pos); m_pos.m_index < cond_max; m_pos.next())
  {
    pfs= &cond_array[m_pos.m_index];
    if (pfs->m_lock.is_populated())
    {
      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);
  DBUG_ASSERT(m_pos.m_index < cond_max);
  pfs= &cond_array[m_pos.m_index];
  if (pfs->m_lock.is_populated())
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_cond_instances::make_row(PFS_cond *pfs)
{
  pfs_lock 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 */
  DBUG_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:
        DBUG_ASSERT(false);
      }
    }
  }

  return 0;
}