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Merge from 5.1 the fix for Bug 12356373

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This commit is contained in:
Inaam Rana
2011-07-19 10:54:59 -04:00
parent f3cc6c566a aa3d29681e
commit fce189fadb
11 changed files with 437 additions and 22 deletions
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25
storage/innobase/include/buf0rea.h
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@ -43,6 +43,31 @@ buf_read_page(
ulint zip_size,/*!< in: compressed page size in bytes, or 0 */
ulint offset);/*!< in: page number */
/********************************************************************//**
Applies a random read-ahead in buf_pool if there are at least a threshold
value of accessed pages from the random read-ahead area. Does not read any
page, not even the one at the position (space, offset), if the read-ahead
mechanism is not activated. NOTE 1: the calling thread may own latches on
pages: to avoid deadlocks this function must be written such that it cannot
end up waiting for these latches! NOTE 2: the calling thread must want
access to the page given: this rule is set to prevent unintended read-aheads
performed by ibuf routines, a situation which could result in a deadlock if
the OS does not support asynchronous i/o.
@return number of page read requests issued; NOTE that if we read ibuf
pages, it may happen that the page at the given page number does not
get read even if we return a positive value!
@return number of page read requests issued */
UNIV_INTERN
ulint
buf_read_ahead_random(
/*==================*/
ulint space, /*!< in: space id */
ulint zip_size, /*!< in: compressed page size in bytes,
or 0 */
ulint offset, /*!< in: page number of a page which
the current thread wants to access */
ibool inside_ibuf); /*!< in: TRUE if we are inside ibuf
routine */
/********************************************************************//**
Applies linear read-ahead if in the buf_pool the page is a border page of
a linear read-ahead area and all the pages in the area have been accessed.
Does not read any page if the read-ahead mechanism is not activated. Note