trx0purge.h

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/*****************************************************************************

Copyright (c) 1996, 2011, 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, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA

*****************************************************************************/

/**************************************************/
#ifndef trx0purge_h
#define trx0purge_h

#include "univ.i"
#include "trx0types.h"
#include "mtr0mtr.h"
#include "trx0sys.h"
#include "que0types.h"
#include "page0page.h"
#include "usr0sess.h"
#include "fil0fil.h"

extern trx_purge_t*     purge_sys;

extern trx_undo_rec_t   trx_purge_dummy_rec;

/********************************************************************/
UNIV_INLINE
fil_addr_t
trx_purge_get_log_from_hist(
/*========================*/
        fil_addr_t      node_addr);     
/********************************************************************/
UNIV_INTERN
void
trx_purge_sys_create(
/*=================*/
        ulint           n_purge_threads,
        ib_bh_t*        ib_bh);         
/********************************************************************/
UNIV_INTERN
void
trx_purge_sys_close(void);
/*======================*/
/************************************************************************
Adds the update undo log as the first log in the history list. Removes the
update undo log segment from the rseg slot if it is too big for reuse. */
UNIV_INTERN
void
trx_purge_add_update_undo_to_history(
/*=================================*/
        trx_t*  trx,            
        page_t* undo_page,      
        mtr_t*  mtr);           
/*******************************************************************/
UNIV_INTERN
ulint
trx_purge(
/*======*/
        ulint   n_purge_threads,        
        ulint   limit,                  
        bool    truncate);              
/*******************************************************************/
UNIV_INTERN
void
trx_purge_stop(void);
/*================*/
/*******************************************************************/
UNIV_INTERN
void
trx_purge_run(void);
/*================*/

enum purge_state_t {
        PURGE_STATE_INIT,               
        PURGE_STATE_RUN,                
        PURGE_STATE_STOP,               
        PURGE_STATE_EXIT,               
        PURGE_STATE_DISABLED            
};

/*******************************************************************/
UNIV_INTERN
purge_state_t
trx_purge_state(void);
/*=================*/

struct purge_iter_t {
        trx_id_t        trx_no;         
        undo_no_t       undo_no;        
};

struct trx_purge_t{
        sess_t*         sess;           
        trx_t*          trx;            
        rw_lock_t       latch;          
        os_event_t      event;          
        ulint           n_stop;         
        volatile bool   running;        
        volatile purge_state_t  state;  
        que_t*          query;          
        read_view_t*    view;           
        volatile ulint  n_submitted;    
        volatile ulint  n_completed;    
        /*------------------------------*/
        /* The following two fields form the 'purge pointer' which advances
        during a purge, and which is used in history list truncation */

        purge_iter_t    iter;           /* Limit up to which we have read and
                                        parsed the UNDO log records.  Not
                                        necessarily purged from the indexes.
                                        Note that this can never be less than
                                        the limit below, we check for this
                                        invariant in trx0purge.cc */
        purge_iter_t    limit;          /* The 'purge pointer' which advances
                                        during a purge, and which is used in
                                        history list truncation */
#ifdef UNIV_DEBUG
        purge_iter_t    done;           /* Indicate 'purge pointer' which have
                                        purged already accurately. */
#endif /* UNIV_DEBUG */
        /*-----------------------------*/
        ibool           next_stored;    
        trx_rseg_t*     rseg;           
        ulint           page_no;        
        ulint           offset;         
        ulint           hdr_page_no;    
        ulint           hdr_offset;     
        /*-----------------------------*/
        mem_heap_t*     heap;           
        /*-----------------------------*/
        ib_bh_t*        ib_bh;          
        ib_mutex_t              bh_mutex;       
};

struct trx_purge_rec_t {
        trx_undo_rec_t* undo_rec;       
        roll_ptr_t      roll_ptr;       
};

#ifndef UNIV_NONINL
#include "trx0purge.ic"
#endif

#endif