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diff --git a/storage/innobase/include/lock0iter.h b/storage/innobase/include/lock0iter.h
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+++ b/storage/innobase/include/lock0iter.h
@@ -0,0 +1,52 @@
+/******************************************************
+Lock queue iterator type and function prototypes.
+
+(c) 2007 Innobase Oy
+
+Created July 16, 2007 Vasil Dimov
+*******************************************************/
+
+#ifndef lock0iter_h
+#define lock0iter_h
+
+#include "univ.i"
+#include "lock0types.h"
+
+typedef struct lock_queue_iterator_struct {
+	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. */
+
+void
+lock_queue_iterator_reset(
+/*======================*/
+	lock_queue_iterator_t*	iter,	/* out: iterator */
+	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). */
+
+lock_t*
+lock_queue_iterator_get_prev(
+/*=========================*/
+					/* out: previous lock or NULL */
+	lock_queue_iterator_t*	iter);	/* in/out: iterator */
+
+#endif /* lock0iter_h */