Function pop_front

phx_percona/percona/sql/binlog.h:176–179

  bool enroll_for(StageID stage, THD *first, mysql_mutex_t *stage_mutex);

  std::pair<bool,THD*> pop_front(StageID stage)
  {
    return m_queue[stage].pop_front();
  }

#ifndef DBUG_OFF
  /**