Function flush_tables

sql/sql_base.cc:560–664

*/

bool flush_tables(THD *thd, flush_tables_type flag)
{
  bool result= TRUE;
  tc_collect_arg collect_arg;
  TABLE *tmp_table;
  flush_tables_error_handler error_handler;
  DBUG_ENTER("flush_tables");

  purge_tables();  /* Flush unused tables and shares */
  DEBUG_SYNC(thd, "after_purge_tables");

  /*
    Loop over all shares and collect shares that have open tables
    TODO:
    Optimize this to only collect shares that have been used for
    write after last time all tables was closed.
  */

  if (!(tmp_table= (TABLE*) my_malloc(PSI_INSTRUMENT_ME, sizeof(*tmp_table),
                                      MYF(MY_WME | MY_THREAD_SPECIFIC))))
    DBUG_RETURN(1);

  my_init_dynamic_array(PSI_INSTRUMENT_ME, &collect_arg.shares,
                        sizeof(TABLE_SHARE*), 100, 100, MYF(0));
  collect_arg.flush_type= flag;
  if (tdc_iterate(thd, tc_collect_used_shares, &collect_arg, true))
  {
    /* Release already collected shares */
    for (uint i= 0 ; i < collect_arg.shares.elements ; i++)
    {
      TABLE_SHARE *share= *dynamic_element(&collect_arg.shares, i,
                                           TABLE_SHARE**);
      tdc_release_share(share);
    }
    goto err;
  }

  /* Call HA_EXTRA_FLUSH on all found shares */

  thd->push_internal_handler(&error_handler);
  for (uint i= 0 ; i < collect_arg.shares.elements ; i++)
  {
    TABLE_SHARE *share= *dynamic_element(&collect_arg.shares, i,
                                         TABLE_SHARE**);
    TABLE *table= tc_acquire_table(thd, share->tdc);
    if (table)
    {
      (void) table->file->extra(HA_EXTRA_FLUSH);
      DEBUG_SYNC(table->in_use, "before_tc_release_table");
      tc_release_table(table);
    }
    else
    {
      /*
        No free TABLE instances available. We have to open a new one.

        Try to take a MDL lock to ensure we can open a new table instance.
        If the lock fails, it means that some DDL operation or flush tables