1 files changed, 40 insertions, 8 deletions
diff --git a/storage/xtradb/include/buf0rea.h b/storage/xtradb/include/buf0rea.h
index b4d25e6fde0..71f62ff7b49 100644
--- a/storage/xtradb/include/buf0rea.h
+++ b/storage/xtradb/include/buf0rea.h
@@ -27,28 +27,59 @@ Created 11/5/1995 Heikki Tuuri
 #define buf0rea_h
 
 #include "univ.i"
+#include "trx0types.h"
 #include "buf0types.h"
 
 /********************************************************************//**
+Low-level function which reads a page asynchronously from a file to the
+buffer buf_pool if it is not already there, in which case does nothing.
+Sets the io_fix flag and sets an exclusive lock on the buffer frame. The
+flag is cleared and the x-lock released by an i/o-handler thread.
+@return 1 if a read request was queued, 0 if the page already resided
+in buf_pool, or if the page is in the doublewrite buffer blocks in
+which case it is never read into the pool, or if the tablespace does
+not exist or is being dropped 
+@return 1 if read request is issued. 0 if it is not */
+UNIV_INTERN
+ulint
+buf_read_page_low(
+/*==============*/
+	ulint*	err,	/*!< out: DB_SUCCESS or DB_TABLESPACE_DELETED if we are
+			trying to read from a non-existent tablespace, or a
+			tablespace which is just now being dropped */
+	ibool	sync,	/*!< in: TRUE if synchronous aio is desired */
+	ulint	mode,	/*!< in: BUF_READ_IBUF_PAGES_ONLY, ...,
+			ORed to OS_AIO_SIMULATED_WAKE_LATER (see below
+			at read-ahead functions) */
+	ulint	space,	/*!< in: space id */
+	ulint	zip_size,/*!< in: compressed page size, or 0 */
+	ibool	unzip,	/*!< in: TRUE=request uncompressed page */
+	ib_int64_t tablespace_version, /*!< in: if the space memory object has
+			this timestamp different from what we are giving here,
+			treat the tablespace as dropped; this is a timestamp we
+			use to stop dangling page reads from a tablespace
+			which we have DISCARDed + IMPORTed back */
+	ulint	offset,	/*!< in: page number */
+	trx_t*	trx);
+/********************************************************************//**
 High-level function which reads a page asynchronously from a file to the
 buffer buf_pool if it is not already there. Sets the io_fix flag and sets
 an exclusive lock on the buffer frame. The flag is cleared and the x-lock
-released by the i/o-handler thread. Does a random read-ahead if it seems
-sensible.
-@return number of page read requests issued: this can be greater than
-1 if read-ahead occurred */
+released by the i/o-handler thread.
+@return TRUE if page has been read in, FALSE in case of failure */
 UNIV_INTERN
-ulint
+ibool
 buf_read_page(
 /*==========*/
 	ulint	space,	/*!< in: space id */
 	ulint	zip_size,/*!< in: compressed page size in bytes, or 0 */
-	ulint	offset);/*!< in: page number */
+	ulint	offset, /*!< in: page number */
+	trx_t*	trx);
 /********************************************************************//**
 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
-that the the algorithm looks at the 'natural' adjacent successor and
+that the algorithm looks at the 'natural' adjacent successor and
 predecessor of the page, which on the leaf level of a B-tree are the next
 and previous page in the chain of leaves. To know these, the page specified
 in (space, offset) must already be present in the buf_pool. Thus, the
@@ -74,8 +105,9 @@ buf_read_ahead_linear(
 /*==================*/
 	ulint	space,	/*!< in: space id */
 	ulint	zip_size,/*!< in: compressed page size in bytes, or 0 */
-	ulint	offset);/*!< in: page number of a page; NOTE: the current thread
+	ulint	offset, /*!< in: page number of a page; NOTE: the current thread
 			must want access to this page (see NOTE 3 above) */
+	trx_t*	trx);
 /********************************************************************//**
 Issues read requests for pages which the ibuf module wants to read in, in
 order to contract the insert buffer tree. Technically, this function is like