mariadb/sql/wsrep_client_service.cc

/* Copyright 2018 Codership Oy <info@codership.com>

   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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include "wsrep_client_service.h"
#include "wsrep_high_priority_service.h"
#include "wsrep_applier.h" /* wsrep_apply_events() */
#include "wsrep_binlog.h"  /* wsrep_dump_rbr_buf() */
#include "wsrep_schema.h"  /* remove_fragments() */
#include "wsrep_thd.h"
#include "wsrep_xid.h"
#include "wsrep_trans_observer.h"

#include "sql_base.h"    /* close_temporary_table() */
#include "sql_class.h"   /* THD */
#include "sql_parse.h"   /* stmt_causes_implicit_commit() */
#include "rpl_filter.h"  /* binlog_filter */
#include "rpl_rli.h"     /* Relay_log_info */
#include "slave.h"   /* opt_log_slave_updates */
#include "transaction.h" /* trans_commit()... */
#include "log.h"      /* stmt_has_updated_trans_table() */
#include "mysql/service_debug_sync.h"
#include "mysql/psi/mysql_thread.h" /* mysql_mutex_assert_owner() */

namespace
{

void debug_sync_caller(THD* thd, const char* sync_point)
{
#ifdef ENABLED_DEBUG_SYNC_OUT
  debug_sync_set_action(thd, sync_point, strlen(sync_point));
#endif
#ifdef ENABLED_DEBUG_SYNC
  if (debug_sync_service) debug_sync_service(thd,sync_point,strlen(sync_point));
#endif

}
}

Wsrep_client_service::Wsrep_client_service(THD* thd,
                                           Wsrep_client_state& client_state)
  : wsrep::client_service()
  , m_thd(thd)
  , m_client_state(client_state)
{ }

void Wsrep_client_service::store_globals()
{
  wsrep_store_threadvars(m_thd);
}

void Wsrep_client_service::reset_globals()
{
  wsrep_reset_threadvars(m_thd);
}

bool Wsrep_client_service::interrupted(
  wsrep::unique_lock<wsrep::mutex>& lock WSREP_UNUSED) const
{
  DBUG_ASSERT(m_thd == current_thd);
  /* Underlying mutex in lock object points to LOCK_thd_data, which
     protects m_thd->wsrep_trx(), LOCK_thd_kill protects m_thd->killed.
     Locking order is:
     1) LOCK_thd_data
     2) LOCK_thd_kill */
  mysql_mutex_assert_owner(static_cast<mysql_mutex_t*>(lock.mutex().native()));
  mysql_mutex_lock(&m_thd->LOCK_thd_kill);
  bool ret= (m_thd->killed != NOT_KILLED);
  if (ret)
  {
    WSREP_DEBUG("wsrep state is interrupted, THD::killed %d trx state %d",
                m_thd->killed,  m_thd->wsrep_trx().state());
  }
  mysql_mutex_unlock(&m_thd->LOCK_thd_kill);
  return ret;
}

int Wsrep_client_service::prepare_data_for_replication()
{
  DBUG_ASSERT(m_thd == current_thd);
  DBUG_ENTER("Wsrep_client_service::prepare_data_for_replication");
  size_t data_len= 0;
  IO_CACHE* cache= wsrep_get_trans_cache(m_thd);

  if (cache)
  {
    m_thd->binlog_flush_pending_rows_event(true);
    if (wsrep_write_cache(m_thd, cache, &data_len))
    {
      WSREP_ERROR("rbr write fail, data_len: %zu",
                  data_len);
      // wsrep_override_error(m_thd, ER_ERROR_DURING_COMMIT);
      DBUG_RETURN(1);
    }
  }

  if (data_len == 0)
  {
    if (m_thd->get_stmt_da()->is_ok()              &&
        m_thd->get_stmt_da()->affected_rows() > 0  &&
        !binlog_filter->is_on() &&
        !m_thd->wsrep_trx().is_streaming())
    {
      WSREP_DEBUG("empty rbr buffer, query: %s, "
                  "affected rows: %llu, "
                  "changed tables: %d, "
                  "sql_log_bin: %d",
                  WSREP_QUERY(m_thd),
                  m_thd->get_stmt_da()->affected_rows(),
                  stmt_has_updated_trans_table(m_thd),
                  m_thd->variables.sql_log_bin);
    }
    else
    {
      WSREP_DEBUG("empty rbr buffer, query: %s", WSREP_QUERY(m_thd));
    }
  }
  DBUG_RETURN(0);
}


void Wsrep_client_service::cleanup_transaction()
{
  DBUG_ASSERT(m_thd == current_thd);
  if (WSREP_EMULATE_BINLOG(m_thd)) wsrep_thd_binlog_trx_reset(m_thd);
  m_thd->wsrep_affected_rows= 0;
}


int Wsrep_client_service::prepare_fragment_for_replication(wsrep::mutable_buffer& buffer)
{
  DBUG_ASSERT(m_thd == current_thd);
  THD* thd= m_thd;
  DBUG_ENTER("Wsrep_client_service::prepare_fragment_for_replication");
  IO_CACHE* cache= wsrep_get_trans_cache(thd);
  thd->binlog_flush_pending_rows_event(true);

  if (!cache)
  {
    DBUG_RETURN(0);
  }

  const my_off_t saved_pos(my_b_tell(cache));
  if (reinit_io_cache(cache, READ_CACHE, thd->wsrep_sr().bytes_certified(), 0, 0))
  {
    DBUG_RETURN(1);
  }

  int ret= 0;
  size_t total_length= 0;
  size_t length= my_b_bytes_in_cache(cache);

  if (!length)
  {
    length= my_b_fill(cache);
  }

  if (length > 0)
  {
    do
    {
      total_length+= length;
      if (total_length > wsrep_max_ws_size)
      {
        WSREP_WARN("transaction size limit (%lu) exceeded: %zu",
                   wsrep_max_ws_size, total_length);
        ret= 1;
        goto cleanup;
      }

      buffer.push_back(reinterpret_cast<const char*>(cache->read_pos),
                       reinterpret_cast<const char*>(cache->read_pos + length));
      cache->read_pos= cache->read_end;
    }
    while (cache->file >= 0 && (length= my_b_fill(cache)));
  }
  DBUG_ASSERT(total_length == buffer.size());
cleanup:
  if (reinit_io_cache(cache, WRITE_CACHE, saved_pos, 0, 0))
  {
    WSREP_WARN("Failed to reinitialize IO cache");
    ret= 1;
  }
  DBUG_RETURN(ret);
}

int Wsrep_client_service::remove_fragments()
{
  DBUG_ENTER("Wsrep_client_service::remove_fragments");
  if (wsrep_schema->remove_fragments(m_thd,
                                     Wsrep_server_state::instance().id(),
                                     m_thd->wsrep_trx().id(),
                                     m_thd->wsrep_sr().fragments()))
  {
    WSREP_DEBUG("Failed to remove fragments from SR storage for transaction "
                "%llu, %llu",
                m_thd->thread_id, m_thd->wsrep_trx().id().get());
    DBUG_RETURN(1);
  }
  DBUG_RETURN(0);
}

bool Wsrep_client_service::statement_allowed_for_streaming() const
{
  /*
    Todo: Decide if implicit commit is allowed with streaming
    replication.
    !stmt_causes_implicit_commit(m_thd, CF_IMPLICIT_COMMIT_BEGIN);
  */
  return true;
}

size_t Wsrep_client_service::bytes_generated() const
{
  IO_CACHE* cache= wsrep_get_trans_cache(m_thd);
  if (cache)
  {
    size_t pending_rows_event_length= 0;
    if (Rows_log_event* ev= m_thd->binlog_get_pending_rows_event(true))
    {
      pending_rows_event_length= ev->get_data_size();
    }
    return my_b_tell(cache) + pending_rows_event_length;
  }
  return 0;
}

void Wsrep_client_service::will_replay()
{
  DBUG_ASSERT(m_thd == current_thd);
  mysql_mutex_lock(&LOCK_wsrep_replaying);
  ++wsrep_replaying;
  mysql_mutex_unlock(&LOCK_wsrep_replaying);
}

enum wsrep::provider::status Wsrep_client_service::replay()
{

  DBUG_ASSERT(m_thd == current_thd);
  DBUG_ENTER("Wsrep_client_service::replay");

  /*
    Allocate separate THD for replaying to avoid tampering
    original THD state during replication event applying.
   */
  THD *replayer_thd= new THD(true, true);
  replayer_thd->thread_stack= m_thd->thread_stack;
  replayer_thd->real_id= pthread_self();
  replayer_thd->prior_thr_create_utime=
      replayer_thd->start_utime= microsecond_interval_timer();
  replayer_thd->set_command(COM_SLEEP);
  replayer_thd->reset_for_next_command(true);

  enum wsrep::provider::status ret;
  {
    Wsrep_replayer_service replayer_service(replayer_thd, m_thd);
    wsrep::provider& provider(replayer_thd->wsrep_cs().provider());
    ret= provider.replay(replayer_thd->wsrep_trx().ws_handle(),
                         &replayer_service);
    replayer_service.replay_status(ret);
  }

  delete replayer_thd;

  mysql_mutex_lock(&LOCK_wsrep_replaying);
  --wsrep_replaying;
  mysql_cond_broadcast(&COND_wsrep_replaying);
  mysql_mutex_unlock(&LOCK_wsrep_replaying);
  DBUG_RETURN(ret);
}

void Wsrep_client_service::wait_for_replayers(wsrep::unique_lock<wsrep::mutex>& lock)
{
  DBUG_ASSERT(m_thd == current_thd);
  lock.unlock();
  mysql_mutex_lock(&LOCK_wsrep_replaying);
  /* We need to check if the THD is BF aborted during condition wait.
     Because the aborter does not know which condition this thread is waiting,
     use timed wait and check if the THD is BF aborted in the loop. */
  while (wsrep_replaying > 0 && !wsrep_is_bf_aborted(m_thd))
  {
    struct timespec wait_time;
    set_timespec_nsec(wait_time, 10000000L);
    mysql_cond_timedwait(&COND_wsrep_replaying, &LOCK_wsrep_replaying,
                         &wait_time);
  }
  mysql_mutex_unlock(&LOCK_wsrep_replaying);
  lock.lock();
}

void Wsrep_client_service::debug_sync(const char* sync_point)
{
  DBUG_ASSERT(m_thd == current_thd);
  debug_sync_caller(m_thd, sync_point);
}

void Wsrep_client_service::debug_crash(const char* crash_point)
{
  // DBUG_ASSERT(m_thd == current_thd);
  DBUG_EXECUTE_IF(crash_point, DBUG_SUICIDE(); );
}

int Wsrep_client_service::bf_rollback()
{
  DBUG_ASSERT(m_thd == current_thd);
  DBUG_ENTER("Wsrep_client_service::rollback");

  int ret= (trans_rollback_stmt(m_thd) || trans_rollback(m_thd));
  if (m_thd->locked_tables_mode && m_thd->lock)
  {
    m_thd->locked_tables_list.unlock_locked_tables(m_thd);
    m_thd->variables.option_bits&= ~OPTION_TABLE_LOCK;
  }
  if (m_thd->global_read_lock.is_acquired())
  {
    m_thd->global_read_lock.unlock_global_read_lock(m_thd);
  }
  m_thd->mdl_context.release_transactional_locks();
  m_thd->mdl_context.release_explicit_locks();

  DBUG_RETURN(ret);
}