mariadb/storage/innobase/include/trx0sys.ic
tsmith@siva.hindu.god baddc4e91c Apply the following InnoDB snapshots:
innodb-5.1-ss1318
innodb-5.1-ss1330
innodb-5.1-ss1332
innodb-5.1-ss1340

Fixes:
- Bug #21409: Incorrect result returned when in READ-COMMITTED with query_cache ON
  At low transaction isolation levels we let each consistent read set
  its own snapshot.

- Bug #23666: strange Innodb_row_lock_time_% values in show status; also millisecs wrong
  On Windows ut_usectime returns secs and usecs relative to the UNIX
  epoch (which is Jan, 1 1970).

- Bug #25494: LATEST DEADLOCK INFORMATION is not always cleared
  lock_deadlock_recursive(): When the search depth or length is exceeded,
  rewind lock_latest_err_file and display the two transactions at the
  point of aborting the search.

- Bug #25927: Foreign key with ON DELETE SET NULL on NOT NULL can crash server
  Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns for which
  there is a foreign key constraint ON ... SET NULL.

- Bug #26835: Repeatable corruption of utf8-enabled tables inside InnoDB
  The bug could be reproduced as follows:

  Define a table so that the first column of the clustered index is
  a VARCHAR or a UTF-8 CHAR in a collation where sequences of bytes
  of differing length are considered equivalent.

  Insert and delete a record.  Before the delete-marked record is
  purged, insert another record whose first column is of different
  length but equivalent to the first record.  Under certain conditions,
  the insertion can be incorrectly performed as update-in-place.

  Likewise, an operation that could be done as update-in-place can
  unnecessarily be performed as delete and insert, but that would not
  cause corruption but merely degraded performance.
2007-03-22 15:59:35 -06:00

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/******************************************************
Transaction system
(c) 1996 Innobase Oy
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "srv0srv.h"
#include "trx0trx.h"
#include "data0type.h"
/* The typedef for rseg slot in the file copy */
typedef byte trx_sysf_rseg_t;
/* Rollback segment specification slot offsets */
/*-------------------------------------------------------------*/
#define TRX_SYS_RSEG_SPACE 0 /* space where the the segment
header is placed; starting with
MySQL/InnoDB 5.1.7, this is
UNIV_UNDEFINED if the slot is unused */
#define TRX_SYS_RSEG_PAGE_NO 4 /* page number where the the segment
header is placed; this is FIL_NULL
if the slot is unused */
/*-------------------------------------------------------------*/
/* Size of a rollback segment specification slot */
#define TRX_SYS_RSEG_SLOT_SIZE 8
/*********************************************************************
Writes the value of max_trx_id to the file based trx system header. */
void
trx_sys_flush_max_trx_id(void);
/*==========================*/
/*******************************************************************
Checks if a page address is the trx sys header page. */
UNIV_INLINE
ibool
trx_sys_hdr_page(
/*=============*/
/* out: TRUE if trx sys header page */
ulint space, /* in: space */
ulint page_no)/* in: page number */
{
if ((space == TRX_SYS_SPACE) && (page_no == TRX_SYS_PAGE_NO)) {
return(TRUE);
}
return(FALSE);
}
/*******************************************************************
Gets the pointer in the nth slot of the rseg array. */
UNIV_INLINE
trx_rseg_t*
trx_sys_get_nth_rseg(
/*=================*/
/* out: pointer to rseg object, NULL if slot
not in use */
trx_sys_t* sys, /* in: trx system */
ulint n) /* in: index of slot */
{
ut_ad(mutex_own(&(kernel_mutex)));
ut_ad(n < TRX_SYS_N_RSEGS);
return(sys->rseg_array[n]);
}
/*******************************************************************
Sets the pointer in the nth slot of the rseg array. */
UNIV_INLINE
void
trx_sys_set_nth_rseg(
/*=================*/
trx_sys_t* sys, /* in: trx system */
ulint n, /* in: index of slot */
trx_rseg_t* rseg) /* in: pointer to rseg object, NULL if slot
not in use */
{
ut_ad(n < TRX_SYS_N_RSEGS);
sys->rseg_array[n] = rseg;
}
/**************************************************************************
Gets a pointer to the transaction system header and x-latches its page. */
UNIV_INLINE
trx_sysf_t*
trx_sysf_get(
/*=========*/
/* out: pointer to system header, page x-latched. */
mtr_t* mtr) /* in: mtr */
{
trx_sysf_t* header;
ut_ad(mtr);
header = TRX_SYS + buf_page_get(TRX_SYS_SPACE, TRX_SYS_PAGE_NO,
RW_X_LATCH, mtr);
#ifdef UNIV_SYNC_DEBUG
buf_page_dbg_add_level(header, SYNC_TRX_SYS_HEADER);
#endif /* UNIV_SYNC_DEBUG */
return(header);
}
/*********************************************************************
Gets the space of the nth rollback segment slot in the trx system
file copy. */
UNIV_INLINE
ulint
trx_sysf_rseg_get_space(
/*====================*/
/* out: space id */
trx_sysf_t* sys_header, /* in: trx sys header */
ulint i, /* in: slot index == rseg id */
mtr_t* mtr) /* in: mtr */
{
ut_ad(mutex_own(&(kernel_mutex)));
ut_ad(sys_header);
ut_ad(i < TRX_SYS_N_RSEGS);
return(mtr_read_ulint(sys_header + TRX_SYS_RSEGS
+ i * TRX_SYS_RSEG_SLOT_SIZE
+ TRX_SYS_RSEG_SPACE, MLOG_4BYTES, mtr));
}
/*********************************************************************
Gets the page number of the nth rollback segment slot in the trx system
header. */
UNIV_INLINE
ulint
trx_sysf_rseg_get_page_no(
/*======================*/
/* out: page number, FIL_NULL
if slot unused */
trx_sysf_t* sys_header, /* in: trx system header */
ulint i, /* in: slot index == rseg id */
mtr_t* mtr) /* in: mtr */
{
ut_ad(sys_header);
ut_ad(mutex_own(&(kernel_mutex)));
ut_ad(i < TRX_SYS_N_RSEGS);
return(mtr_read_ulint(sys_header + TRX_SYS_RSEGS
+ i * TRX_SYS_RSEG_SLOT_SIZE
+ TRX_SYS_RSEG_PAGE_NO, MLOG_4BYTES, mtr));
}
/*********************************************************************
Sets the space id of the nth rollback segment slot in the trx system
file copy. */
UNIV_INLINE
void
trx_sysf_rseg_set_space(
/*====================*/
trx_sysf_t* sys_header, /* in: trx sys file copy */
ulint i, /* in: slot index == rseg id */
ulint space, /* in: space id */
mtr_t* mtr) /* in: mtr */
{
ut_ad(mutex_own(&(kernel_mutex)));
ut_ad(sys_header);
ut_ad(i < TRX_SYS_N_RSEGS);
mlog_write_ulint(sys_header + TRX_SYS_RSEGS
+ i * TRX_SYS_RSEG_SLOT_SIZE
+ TRX_SYS_RSEG_SPACE,
space,
MLOG_4BYTES, mtr);
}
/*********************************************************************
Sets the page number of the nth rollback segment slot in the trx system
header. */
UNIV_INLINE
void
trx_sysf_rseg_set_page_no(
/*======================*/
trx_sysf_t* sys_header, /* in: trx sys header */
ulint i, /* in: slot index == rseg id */
ulint page_no, /* in: page number, FIL_NULL if the
slot is reset to unused */
mtr_t* mtr) /* in: mtr */
{
ut_ad(mutex_own(&(kernel_mutex)));
ut_ad(sys_header);
ut_ad(i < TRX_SYS_N_RSEGS);
mlog_write_ulint(sys_header + TRX_SYS_RSEGS
+ i * TRX_SYS_RSEG_SLOT_SIZE
+ TRX_SYS_RSEG_PAGE_NO,
page_no,
MLOG_4BYTES, mtr);
}
/*********************************************************************
Writes a trx id to an index page. In case that the id size changes in
some future version, this function should be used instead of
mach_write_... */
UNIV_INLINE
void
trx_write_trx_id(
/*=============*/
byte* ptr, /* in: pointer to memory where written */
dulint id) /* in: id */
{
ut_ad(DATA_TRX_ID_LEN == 6);
mach_write_to_6(ptr, id);
}
/*********************************************************************
Reads a trx id from an index page. In case that the id size changes in
some future version, this function should be used instead of
mach_read_... */
UNIV_INLINE
dulint
trx_read_trx_id(
/*============*/
/* out: id */
byte* ptr) /* in: pointer to memory from where to read */
{
ut_ad(DATA_TRX_ID_LEN == 6);
return(mach_read_from_6(ptr));
}
/********************************************************************
Looks for the trx handle with the given id in trx_list. */
UNIV_INLINE
trx_t*
trx_get_on_id(
/*==========*/
/* out: the trx handle or NULL if not found */
dulint trx_id) /* in: trx id to search for */
{
trx_t* trx;
ut_ad(mutex_own(&(kernel_mutex)));
trx = UT_LIST_GET_FIRST(trx_sys->trx_list);
while (trx != NULL) {
if (0 == ut_dulint_cmp(trx_id, trx->id)) {
return(trx);
}
trx = UT_LIST_GET_NEXT(trx_list, trx);
}
return(NULL);
}
/********************************************************************
Returns the minumum trx id in trx list. This is the smallest id for which
the trx can possibly be active. (But, you must look at the trx->conc_state to
find out if the minimum trx id transaction itself is active, or already
committed.) */
UNIV_INLINE
dulint
trx_list_get_min_trx_id(void)
/*=========================*/
/* out: the minimum trx id, or trx_sys->max_trx_id
if the trx list is empty */
{
trx_t* trx;
ut_ad(mutex_own(&(kernel_mutex)));
trx = UT_LIST_GET_LAST(trx_sys->trx_list);
if (trx == NULL) {
return(trx_sys->max_trx_id);
}
return(trx->id);
}
/********************************************************************
Checks if a transaction with the given id is active. */
UNIV_INLINE
ibool
trx_is_active(
/*==========*/
/* out: TRUE if active */
dulint trx_id) /* in: trx id of the transaction */
{
trx_t* trx;
ut_ad(mutex_own(&(kernel_mutex)));
if (ut_dulint_cmp(trx_id, trx_list_get_min_trx_id()) < 0) {
return(FALSE);
}
if (ut_dulint_cmp(trx_id, trx_sys->max_trx_id) >= 0) {
/* There must be corruption: we return TRUE because this
function is only called by lock_clust_rec_some_has_impl()
and row_vers_impl_x_locked_off_kernel() and they have
diagnostic prints in this case */
return(TRUE);
}
trx = trx_get_on_id(trx_id);
if (trx && (trx->conc_state == TRX_ACTIVE
|| trx->conc_state == TRX_PREPARED)) {
return(TRUE);
}
return(FALSE);
}
/*********************************************************************
Allocates a new transaction id. */
UNIV_INLINE
dulint
trx_sys_get_new_trx_id(void)
/*========================*/
/* out: new, allocated trx id */
{
dulint id;
ut_ad(mutex_own(&kernel_mutex));
/* VERY important: after the database is started, max_trx_id value is
divisible by TRX_SYS_TRX_ID_WRITE_MARGIN, and the following if
will evaluate to TRUE when this function is first time called,
and the value for trx id will be written to disk-based header!
Thus trx id values will not overlap when the database is
repeatedly started! */
if (ut_dulint_get_low(trx_sys->max_trx_id)
% TRX_SYS_TRX_ID_WRITE_MARGIN == 0) {
trx_sys_flush_max_trx_id();
}
id = trx_sys->max_trx_id;
UT_DULINT_INC(trx_sys->max_trx_id);
return(id);
}
/*********************************************************************
Allocates a new transaction number. */
UNIV_INLINE
dulint
trx_sys_get_new_trx_no(void)
/*========================*/
/* out: new, allocated trx number */
{
ut_ad(mutex_own(&kernel_mutex));
return(trx_sys_get_new_trx_id());
}