trx0roll.c

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	mutex_exit(&kernel_mutex);

	if (trx == NULL) {
		ut_print_timestamp(stderr);
		fprintf(stderr,
		"  InnoDB: Rollback of non-prepared transactions completed\n");

 		mem_heap_free(heap);

		goto leave_function;
	}

	trx->sess = trx_dummy_sess;

	if (trx->conc_state == TRX_COMMITTED_IN_MEMORY) {	
		fprintf(stderr, "InnoDB: Cleaning up trx with id %lu %lu\n",
					(ulong) ut_dulint_get_high(trx->id),
					(ulong) ut_dulint_get_low(trx->id));

		trx_cleanup_at_db_startup(trx);
					
		mem_heap_free(heap);

		goto loop;
	}

	fork = que_fork_create(NULL, NULL, QUE_FORK_RECOVERY, heap);
	fork->trx = trx;

	thr = que_thr_create(fork, heap);

	roll_node = roll_node_create(heap);

	thr->child = roll_node;
	roll_node->common.parent = thr;

	mutex_enter(&kernel_mutex);	

	trx->graph = fork;

	ut_a(thr == que_fork_start_command(fork));
	
	trx_roll_crash_recv_trx	= trx;
	trx_roll_max_undo_no = ut_conv_dulint_to_longlong(trx->undo_no);
	trx_roll_progress_printed_pct = 0;
	rows_to_undo = trx_roll_max_undo_no;

	if (rows_to_undo > 1000000000) {
		rows_to_undo = rows_to_undo / 1000000;
		unit = "M";
	}

	ut_print_timestamp(stderr);
	fprintf(stderr,
"  InnoDB: Rolling back trx with id %lu %lu, %lu%s rows to undo\n",
					(ulong) ut_dulint_get_high(trx->id),
					(ulong) ut_dulint_get_low(trx->id),
					(ulong) rows_to_undo, unit);
	mutex_exit(&kernel_mutex);

	trx->mysql_thread_id = os_thread_get_curr_id();

	trx->mysql_process_no = os_proc_get_number();

	if (trx->dict_operation) {
		row_mysql_lock_data_dictionary(trx);
	}

	que_run_threads(thr);

	mutex_enter(&kernel_mutex);

	while (trx->que_state != TRX_QUE_RUNNING) {

		mutex_exit(&kernel_mutex);

		fprintf(stderr,
		"InnoDB: Waiting for rollback of trx id %lu to end\n",
					(ulong) ut_dulint_get_low(trx->id));
		os_thread_sleep(100000);

		mutex_enter(&kernel_mutex);
	}

	mutex_exit(&kernel_mutex);

	if (trx->dict_operation) {
		/* If the transaction was for a dictionary operation, we
		drop the relevant table, if it still exists */

		fprintf(stderr,
"InnoDB: Dropping table with id %lu %lu in recovery if it exists\n",
			(ulong) ut_dulint_get_high(trx->table_id),
			(ulong) ut_dulint_get_low(trx->table_id));

		table = dict_table_get_on_id_low(trx->table_id, trx);

		if (table) {		
			fputs("InnoDB: Table found: dropping table ", stderr);
			ut_print_name(stderr, trx, table->name);
			fputs(" in recovery\n", stderr);

			err = row_drop_table_for_mysql(table->name, trx, TRUE);

			ut_a(err == (int) DB_SUCCESS);
		}
	}

	if (trx->dict_operation) {
		row_mysql_unlock_data_dictionary(trx);
	}

	fprintf(stderr, "\nInnoDB: Rolling back of trx id %lu %lu completed\n",
					(ulong) ut_dulint_get_high(trx->id),
					(ulong) ut_dulint_get_low(trx->id));
	mem_heap_free(heap);

	trx_roll_crash_recv_trx	= NULL;

	goto loop;

leave_function:
	/* We count the number of threads in os_thread_exit(). A created
	thread should always use that to exit and not use return() to exit. */

	os_thread_exit(NULL);

	/* The following is dummy code to keep the compiler happy: */

#ifndef __WIN__
        return(NULL);
#else
        return(0);
#endif
}
	
/***********************************************************************
Creates an undo number array. */

trx_undo_arr_t*
trx_undo_arr_create(void)
/*=====================*/
{
	trx_undo_arr_t*	arr;
	mem_heap_t*	heap;
	ulint		i;
	
	heap = mem_heap_create(1024);

	arr = mem_heap_alloc(heap, sizeof(trx_undo_arr_t));

	arr->infos = mem_heap_alloc(heap, sizeof(trx_undo_inf_t)
						* UNIV_MAX_PARALLELISM);
	arr->n_cells = UNIV_MAX_PARALLELISM;
	arr->n_used = 0;

	arr->heap = heap;

	for (i = 0; i < UNIV_MAX_PARALLELISM; i++) {

		(trx_undo_arr_get_nth_info(arr, i))->in_use = FALSE;
	}

	return(arr);
}

/***********************************************************************
Frees an undo number array. */

void
trx_undo_arr_free(
/*==============*/
	trx_undo_arr_t*	arr)	/* in: undo number array */
{
	ut_ad(arr->n_used == 0);

	mem_heap_free(arr->heap);
}

/***********************************************************************
Stores info of an undo log record to the array if it is not stored yet. */
static
ibool
trx_undo_arr_store_info(
/*====================*/
			/* out: FALSE if the record already existed in the
			array */
	trx_t*	trx,	/* in: transaction */
	dulint	undo_no)/* in: undo number */
{
	trx_undo_inf_t*	cell;
	trx_undo_inf_t*	stored_here;
	trx_undo_arr_t*	arr;
	ulint		n_used;
	ulint		n;
	ulint		i;

	n = 0;
	arr = trx->undo_no_arr;
	n_used = arr->n_used;
	stored_here = NULL;
	
	for (i = 0;; i++) {
		cell = trx_undo_arr_get_nth_info(arr, i);

		if (!cell->in_use) {
			if (!stored_here) {
				/* Not in use, we may store here */
				cell->undo_no = undo_no;
				cell->in_use = TRUE;

				arr->n_used++;

				stored_here = cell;
			}
		} else {
			n++;

			if (0 == ut_dulint_cmp(cell->undo_no, undo_no)) {

				if (stored_here) {
					stored_here->in_use = FALSE;
					ut_ad(arr->n_used > 0);
					arr->n_used--;
				}

				ut_ad(arr->n_used == n_used);

				return(FALSE);
			}
		}
		
		if (n == n_used && stored_here) {

			ut_ad(arr->n_used == 1 + n_used);

			return(TRUE);
		}
	}
}

/***********************************************************************
Removes an undo number from the array. */
static
void
trx_undo_arr_remove_info(
/*=====================*/
	trx_undo_arr_t*	arr,	/* in: undo number array */
	dulint		undo_no)/* in: undo number */
{
	trx_undo_inf_t*	cell;
	ulint		n_used;
	ulint		n;
	ulint		i;

	n_used = arr->n_used;
	n = 0;

	for (i = 0;; i++) {
		cell = trx_undo_arr_get_nth_info(arr, i);

		if (cell->in_use
			     && 0 == ut_dulint_cmp(cell->undo_no, undo_no)) {

			cell->in_use = FALSE;
				
			ut_ad(arr->n_used > 0);

			arr->n_used--;

			return;
		}
	}
}

/***********************************************************************
Gets the biggest undo number in an array. */
static
dulint
trx_undo_arr_get_biggest(
/*=====================*/
				/* out: biggest value, ut_dulint_zero if
				the array is empty */
	trx_undo_arr_t*	arr)	/* in: undo number array */
{
	trx_undo_inf_t*	cell;
	ulint		n_used;
	dulint		biggest;
	ulint		n;
	ulint		i;
	
	n = 0;
	n_used = arr->n_used;
	biggest = ut_dulint_zero;
	
	for (i = 0;; i++) {
		cell = trx_undo_arr_get_nth_info(arr, i);

		if (cell->in_use) {
			n++;
			if (ut_dulint_cmp(cell->undo_no, biggest) > 0) {

				biggest = cell->undo_no;
			}
		}
		
		if (n == n_used) {
			return(biggest);
		}
	}
}

/***************************************************************************
Tries truncate the undo logs. */

void
trx_roll_try_truncate(
/*==================*/
	trx_t*	trx)	/* in: transaction */
{
	trx_undo_arr_t*	arr;
	dulint		limit;
	dulint		biggest;
	
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(trx->undo_mutex)));
	ut_ad(mutex_own(&((trx->rseg)->mutex)));
#endif /* UNIV_SYNC_DEBUG */

	trx->pages_undone = 0;
	
	arr = trx->undo_no_arr;

	limit = trx->undo_no;

	if (arr->n_used > 0) {
		biggest = trx_undo_arr_get_biggest(arr);

	    	if (ut_dulint_cmp(biggest, limit) >= 0) {

	    		limit = ut_dulint_add(biggest, 1);
	    	}
	}

	if (trx->insert_undo) {
		trx_undo_truncate_end(trx, trx->insert_undo, limit);
	}

	if (trx->update_undo) {
		trx_undo_truncate_end(trx, trx->update_undo, limit);
	}
}

/***************************************************************************
Pops the topmost undo log record in a single undo log and updates the info
about the topmost record in the undo log memory struct. */
static
trx_undo_rec_t*
trx_roll_pop_top_rec(
/*=================*/
				/* out: undo log record, the page s-latched */
	trx_t*		trx,	/* in: transaction */
	trx_undo_t*	undo,	/* in: undo log */
	mtr_t*		mtr)	/* in: mtr */
{
	page_t* 	undo_page;
	ulint		offset;
	trx_undo_rec_t*	prev_rec;
	page_t*		prev_rec_page;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&(trx->undo_mutex)));
#endif /* UNIV_SYNC_DEBUG */

	undo_page = trx_undo_page_get_s_latched(undo->space,
						undo->top_page_no, mtr);
	offset = undo->top_offset;

/*	fprintf(stderr, "Thread %lu undoing trx %lu undo record %lu\n",
		os_thread_get_curr_id(), ut_dulint_get_low(trx->id),
		ut_dulint_get_low(undo->top_undo_no)); */

	prev_rec = trx_undo_get_prev_rec(undo_page + offset,
					undo->hdr_page_no, undo->hdr_offset,
									mtr);
	if (prev_rec == NULL) {

		undo->empty = TRUE;
	} else {
		prev_rec_page = buf_frame_align(prev_rec);
	
		if (prev_rec_page != undo_page) {

			trx->pages_undone++;
		}
	
		undo->top_page_no = buf_frame_get_page_no(prev_rec_page);
		undo->top_offset  = prev_rec - prev_rec_page;
		undo->top_undo_no = trx_undo_rec_get_undo_no(prev_rec);
	}

	return(undo_page + offset);
}

/************************************************************************
Pops the topmost record when the two undo logs of a transaction are seen
as a single stack of records ordered by their undo numbers. Inserts the
undo number of the popped undo record to the array of currently processed
undo numbers in the transaction. When the query thread finishes processing
of this undo record, it must be released with trx_undo_rec_release. */

trx_undo_rec_t*
trx_roll_pop_top_rec_of_trx(
/*========================*/
				/* out: undo log record copied to heap, NULL
				if none left, or if the undo number of the
				top record would be less than the limit */
	trx_t*		trx,	/* in: transaction */
	dulint		limit,	/* in: least undo number we need */
	dulint*		roll_ptr,/* out: roll pointer to undo record */
	mem_heap_t*	heap)	/* in: memory heap where copied */
{
	trx_undo_t*	undo;
	trx_undo_t*	ins_undo;
	trx_undo_t*	upd_undo;
	trx_undo_rec_t*	undo_rec;
	trx_undo_rec_t*	undo_rec_copy;
	dulint		undo_no;
	ibool		is_insert;
	trx_rseg_t*	rseg;
	ulint		progress_pct;
	mtr_t		mtr;
	
	rseg = trx->rseg;
try_again:
	mutex_enter(&(trx->undo_mutex));

	if (trx->pages_undone >= TRX_ROLL_TRUNC_THRESHOLD) {
		mutex_enter(&(rseg->mutex));

		trx_roll_try_truncate(trx);

		mutex_exit(&(rseg->mutex));
	}

	ins_undo = trx->insert_undo;
	upd_undo = trx->update_undo;