/********************************************************************//**
Removes unnecessary history data from a rollback segment. */
static
void
trx_purge_truncate_rseg_history(
/*============================*/
trx_rseg_t* rseg, /*!< in: rollback segment */
trx_id_t limit_trx_no, /*!< in: remove update undo logs whose
trx number is < limit_trx_no */
undo_no_t limit_undo_no) /*!< in: if transaction number is equal
to limit_trx_no, truncate undo records
with undo number < limit_undo_no */
{
fil_addr_t hdr_addr;
fil_addr_t prev_hdr_addr;
trx_rsegf_t* rseg_hdr;
page_t* undo_page;
trx_ulogf_t* log_hdr;
trx_usegf_t* seg_hdr;
ulint n_removed_logs = 0;
mtr_t mtr;
trx_id_t undo_trx_no;
mtr_start(&mtr);
mutex_enter(&(rseg->mutex));
rseg_hdr = trx_rsegf_get(rseg->space, rseg->zip_size,
rseg->page_no, &mtr);
hdr_addr = trx_purge_get_log_from_hist(
flst_get_last(rseg_hdr + TRX_RSEG_HISTORY, &mtr));
loop:
if (hdr_addr.page == FIL_NULL) {
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
return;
}
undo_page = trx_undo_page_get(rseg->space, rseg->zip_size,
hdr_addr.page, &mtr);
log_hdr = undo_page + hdr_addr.boffset;
undo_trx_no = mach_read_from_8(log_hdr + TRX_UNDO_TRX_NO);
if (undo_trx_no >= limit_trx_no) {
if (undo_trx_no == limit_trx_no) {
trx_undo_truncate_start(rseg, rseg->space,
hdr_addr.page,
hdr_addr.boffset,
limit_undo_no);
}
mutex_enter(&kernel_mutex);
ut_a(trx_sys->rseg_history_len >= n_removed_logs);
trx_sys->rseg_history_len -= n_removed_logs;
mutex_exit(&kernel_mutex);
flst_truncate_end(rseg_hdr + TRX_RSEG_HISTORY,
log_hdr + TRX_UNDO_HISTORY_NODE,
n_removed_logs, &mtr);
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
return;
}
prev_hdr_addr = trx_purge_get_log_from_hist(
flst_get_prev_addr(log_hdr + TRX_UNDO_HISTORY_NODE, &mtr));
n_removed_logs++;
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
if ((mach_read_from_2(seg_hdr + TRX_UNDO_STATE) == TRX_UNDO_TO_PURGE)
&& (mach_read_from_2(log_hdr + TRX_UNDO_NEXT_LOG) == 0)) {
/* We can free the whole log segment */
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
trx_purge_free_segment(rseg, hdr_addr, n_removed_logs);
n_removed_logs = 0;
} else {
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
}
mtr_start(&mtr);
mutex_enter(&(rseg->mutex));
rseg_hdr = trx_rsegf_get(rseg->space, rseg->zip_size,
rseg->page_no, &mtr);
hdr_addr = prev_hdr_addr;
goto loop;
}
/********************************************************************//**
Adds the update undo log as the first log in the history list. Removes the
update undo log segment from the rseg slot if it is too big for reuse. */
UNIV_INTERN
void
trx_purge_add_update_undo_to_history(
/*=================================*/
trx_t* trx, /*!< in: transaction */
page_t* undo_page, /*!< in: update undo log header page,
x-latched */
mtr_t* mtr) /*!< in: mtr */
{
trx_undo_t* undo;
trx_rsegf_t* rseg_header;
trx_ulogf_t* undo_header;
undo = trx->update_undo;
ut_ad(undo);
ut_ad(mutex_own(&undo->rseg->mutex));
rseg_header = trx_rsegf_get(
undo->rseg->space, undo->rseg->zip_size, undo->rseg->page_no,
mtr);
undo_header = undo_page + undo->hdr_offset;
/* Add the log as the first in the history list */
if (undo->state != TRX_UNDO_CACHED) {
ulint hist_size;
#ifdef UNIV_DEBUG
trx_usegf_t* seg_header = undo_page + TRX_UNDO_SEG_HDR;
#endif /* UNIV_DEBUG */
/* The undo log segment will not be reused */
if (UNIV_UNLIKELY(undo->id >= TRX_RSEG_N_SLOTS)) {
fprintf(stderr,
"InnoDB: Error: undo->id is %lu\n",
(ulong) undo->id);
ut_error;
}
trx_rsegf_set_nth_undo(rseg_header, undo->id, FIL_NULL, mtr);
hist_size = mtr_read_ulint(
rseg_header + TRX_RSEG_HISTORY_SIZE, MLOG_4BYTES, mtr);
ut_ad(undo->size == flst_get_len(
seg_header + TRX_UNDO_PAGE_LIST, mtr));
mlog_write_ulint(
rseg_header + TRX_RSEG_HISTORY_SIZE,
hist_size + undo->size, MLOG_4BYTES, mtr);
}
flst_add_first(
rseg_header + TRX_RSEG_HISTORY,
undo_header + TRX_UNDO_HISTORY_NODE, mtr);
/* Write the trx number to the undo log header */
mlog_write_ull(undo_header + TRX_UNDO_TRX_NO, trx->no, mtr);
/* Write information about delete markings to the undo log header */
if (!undo->del_marks) {
mlog_write_ulint(
undo_header + TRX_UNDO_DEL_MARKS, FALSE,
MLOG_2BYTES, mtr);
}
if (undo->rseg->last_page_no == FIL_NULL) {
undo->rseg->last_trx_no = trx->no;
undo->rseg->last_offset = undo->hdr_offset;
undo->rseg->last_page_no = undo->hdr_page_no;
undo->rseg->last_del_marks = undo->del_marks;
/* FIXME: Add a bin heap validate function to check that
the rseg exists. */
}
mutex_enter(&kernel_mutex);
trx_sys->rseg_history_len++;
mutex_exit(&kernel_mutex);
// if (!(trx_sys->rseg_history_len % srv_purge_batch_size)) { /*should wake up always*/
/* Inform the purge thread that there is work to do. */
srv_wake_purge_thread_if_not_active();
// }
}
/**********************************************************************//**
Frees an undo log segment which is in the history list. Cuts the end of the
history list at the youngest undo log in this segment. */
static
void
trx_purge_free_segment(
/*===================*/
trx_rseg_t* rseg, /*!< in: rollback segment */
fil_addr_t hdr_addr, /*!< in: the file address of log_hdr */
ulint n_removed_logs) /*!< in: count of how many undo logs we
will cut off from the end of the
history list */
{
page_t* undo_page;
trx_rsegf_t* rseg_hdr;
trx_ulogf_t* log_hdr;
trx_usegf_t* seg_hdr;
ibool freed;
ulint seg_size;
ulint hist_size;
ibool marked = FALSE;
mtr_t mtr;
/* fputs("Freeing an update undo log segment\n", stderr); */
loop:
mtr_start(&mtr);
mutex_enter(&(rseg->mutex));
rseg_hdr = trx_rsegf_get(rseg->space, rseg->zip_size,
rseg->page_no, &mtr);
undo_page = trx_undo_page_get(rseg->space, rseg->zip_size,
hdr_addr.page, &mtr);
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
log_hdr = undo_page + hdr_addr.boffset;
/* Mark the last undo log totally purged, so that if the system
crashes, the tail of the undo log will not get accessed again. The
list of pages in the undo log tail gets inconsistent during the
freeing of the segment, and therefore purge should not try to access
them again. */
if (!marked) {
mlog_write_ulint(log_hdr + TRX_UNDO_DEL_MARKS, FALSE,
MLOG_2BYTES, &mtr);
marked = TRUE;
}
freed = fseg_free_step_not_header(seg_hdr + TRX_UNDO_FSEG_HEADER,
&mtr);
if (!freed) {
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
goto loop;
}
/* The page list may now be inconsistent, but the length field
stored in the list base node tells us how big it was before we
started the freeing. */
seg_size = flst_get_len(seg_hdr + TRX_UNDO_PAGE_LIST, &mtr);
/* We may free the undo log segment header page; it must be freed
within the same mtr as the undo log header is removed from the
history list: otherwise, in case of a database crash, the segment
could become inaccessible garbage in the file space. */
flst_cut_end(rseg_hdr + TRX_RSEG_HISTORY,
log_hdr + TRX_UNDO_HISTORY_NODE, n_removed_logs, &mtr);
mutex_enter(&kernel_mutex);
ut_ad(trx_sys->rseg_history_len >= n_removed_logs);
trx_sys->rseg_history_len -= n_removed_logs;
mutex_exit(&kernel_mutex);
freed = FALSE;
while (!freed) {
/* Here we assume that a file segment with just the header
page can be freed in a few steps, so that the buffer pool
is not flooded with bufferfixed pages: see the note in
fsp0fsp.c. */
freed = fseg_free_step(seg_hdr + TRX_UNDO_FSEG_HEADER,
&mtr);
}
hist_size = mtr_read_ulint(rseg_hdr + TRX_RSEG_HISTORY_SIZE,
MLOG_4BYTES, &mtr);
ut_ad(hist_size >= seg_size);
mlog_write_ulint(rseg_hdr + TRX_RSEG_HISTORY_SIZE,
hist_size - seg_size, MLOG_4BYTES, &mtr);
ut_ad(rseg->curr_size >= seg_size);
rseg->curr_size -= seg_size;
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
}
/********************************************************************//**
Adds the update undo log as the first log in the history list. Removes the
update undo log segment from the rseg slot if it is too big for reuse. */
UNIV_INTERN
void
trx_purge_add_update_undo_to_history(
/*=================================*/
trx_t* trx, /*!< in: transaction */
page_t* undo_page, /*!< in: update undo log header page,
x-latched */
mtr_t* mtr) /*!< in: mtr */
{
trx_undo_t* undo;
trx_rseg_t* rseg;
trx_rsegf_t* rseg_header;
#ifdef UNIV_DEBUG
trx_usegf_t* seg_header;
#endif /* UNIV_DEBUG */
trx_ulogf_t* undo_header;
ulint hist_size;
undo = trx->update_undo;
ut_ad(undo);
rseg = undo->rseg;
ut_ad(mutex_own(&(rseg->mutex)));
rseg_header = trx_rsegf_get(rseg->space, rseg->zip_size,
rseg->page_no, mtr);
undo_header = undo_page + undo->hdr_offset;
#ifdef UNIV_DEBUG
seg_header = undo_page + TRX_UNDO_SEG_HDR;
#endif /* UNIV_DEBUG */
if (undo->state != TRX_UNDO_CACHED) {
/* The undo log segment will not be reused */
if (undo->id >= TRX_RSEG_N_SLOTS) {
fprintf(stderr,
"InnoDB: Error: undo->id is %lu\n",
(ulong) undo->id);
ut_error;
}
trx_rsegf_set_nth_undo(rseg_header, undo->id, FIL_NULL, mtr);
hist_size = mtr_read_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE,
MLOG_4BYTES, mtr);
ut_ad(undo->size == flst_get_len(
seg_header + TRX_UNDO_PAGE_LIST, mtr));
mlog_write_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE,
hist_size + undo->size, MLOG_4BYTES, mtr);
}
/* Add the log as the first in the history list */
flst_add_first(rseg_header + TRX_RSEG_HISTORY,
undo_header + TRX_UNDO_HISTORY_NODE, mtr);
mutex_enter(&kernel_mutex);
trx_sys->rseg_history_len++;
mutex_exit(&kernel_mutex);
/* Write the trx number to the undo log header */
mlog_write_dulint(undo_header + TRX_UNDO_TRX_NO, trx->no, mtr);
/* Write information about delete markings to the undo log header */
if (!undo->del_marks) {
mlog_write_ulint(undo_header + TRX_UNDO_DEL_MARKS, FALSE,
MLOG_2BYTES, mtr);
}
if (rseg->last_page_no == FIL_NULL) {
rseg->last_page_no = undo->hdr_page_no;
rseg->last_offset = undo->hdr_offset;
rseg->last_trx_no = trx->no;
rseg->last_del_marks = undo->del_marks;
}
}