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/*****************************************************************************
Copyright (C) 2007, 2009, Innobase Oy. 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
St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/**************************************************//**
@file include/lock0iter.h
Lock queue iterator type and function prototypes.
Created July 16, 2007 Vasil Dimov
*******************************************************/
#ifndef lock0iter_h
#define lock0iter_h
#include "univ.i"
#include "lock0types.h"
typedef struct lock_queue_iterator_struct {
const lock_t* current_lock;
/* In case this is a record lock queue (not table lock queue)
then bit_no is the record number within the heap in which the
record is stored. */
ulint bit_no;
} lock_queue_iterator_t;
/*******************************************************************//**
Initialize lock queue iterator so that it starts to iterate from
"lock". bit_no specifies the record number within the heap where the
record is stored. It can be undefined (ULINT_UNDEFINED) in two cases:
1. If the lock is a table lock, thus we have a table lock queue;
2. If the lock is a record lock and it is a wait lock. In this case
bit_no is calculated in this function by using
lock_rec_find_set_bit(). There is exactly one bit set in the bitmap
of a wait lock. */
UNIV_INTERN
void
lock_queue_iterator_reset(
/*======================*/
lock_queue_iterator_t* iter, /*!< out: iterator */
const lock_t* lock, /*!< in: lock to start from */
ulint bit_no);/*!< in: record number in the
heap */
/*******************************************************************//**
Gets the previous lock in the lock queue, returns NULL if there are no
more locks (i.e. the current lock is the first one). The iterator is
receded (if not-NULL is returned).
@return previous lock or NULL */
const lock_t*
lock_queue_iterator_get_prev(
/*=========================*/
lock_queue_iterator_t* iter); /*!< in/out: iterator */
#endif /* lock0iter_h */
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