Fix for bug# 16979, this is a major change in InnoDB auto-inc handling. There

is one test that fails as of this commit. The updated test case should be
part of the snapshot from MySQL shortly.

Fix for bug# 27950 - Init AUTOINC from delete_row().

Fix for bug# 28781 - Use value specified by MySQL, in update_row().

Summary of structural changes:
==============================
InnoDB needs to hold a table level lock for AUTOINC allocations to overcome
the non-determinism inherent in MySQL SBR for INSERT ... SELECT. In this fix 
for simple INSERT statements (including multi-value inserts), we try and avoid
acquiring the special AUTOINC table level lock unless another transaction has
already reserved the AUTOINC table level lock, in which case we fall back
to the old behavior of acquiring the AUTOINC table level lock.

The max AUTOINC value is now read directly using the low level interface
of InnoDB.

dict/dict0dict.c

@@ -418,6 +418,18 @@ dict_table_get_col_name(
 	return(s);
 }
 
+
+/************************************************************************
+Acquire the autoinc lock.*/
+
+void
+dict_table_autoinc_lock(
+/*====================*/
+	dict_table_t*	table)
+{
+	mutex_enter(&table->autoinc_mutex);
+}
+
 /************************************************************************
 Initializes the autoinc counter. It is not an error to initialize an already
 initialized counter. */
@@ -428,54 +440,8 @@ dict_table_autoinc_initialize(
 	dict_table_t*	table,	/* in: table */
 	ib_longlong	value)	/* in: next value to assign to a row */
 {
-	mutex_enter(&(table->autoinc_mutex));
-
 	table->autoinc_inited = TRUE;
 	table->autoinc = value;
-
-	mutex_exit(&(table->autoinc_mutex));
-}
-
-/************************************************************************
-Gets the next autoinc value (== autoinc counter value), 0 if not yet
-initialized. If initialized, increments the counter by 1. */
-
-ib_longlong
-dict_table_autoinc_get(
-/*===================*/
-				/* out: value for a new row, or 0 */
-	dict_table_t*	table)	/* in: table */
-{
-	ib_longlong	value;
-
-	mutex_enter(&(table->autoinc_mutex));
-
-	if (!table->autoinc_inited) {
-
-		value = 0;
-	} else {
-		value = table->autoinc;
-		table->autoinc = table->autoinc + 1;
-	}
-
-	mutex_exit(&(table->autoinc_mutex));
-
-	return(value);
-}
-
-/************************************************************************
-Decrements the autoinc counter value by 1. */
-
-void
-dict_table_autoinc_decrement(
-/*=========================*/
-	dict_table_t*	table)	/* in: table */
-{
-	mutex_enter(&(table->autoinc_mutex));
-
-	table->autoinc = table->autoinc - 1;
-
-	mutex_exit(&(table->autoinc_mutex));
 }
 
 /************************************************************************
@@ -490,32 +456,6 @@ dict_table_autoinc_read(
 {
 	ib_longlong	value;
 
-	mutex_enter(&(table->autoinc_mutex));
-
-	if (!table->autoinc_inited) {
-
-		value = 0;
-	} else {
-		value = table->autoinc;
-	}
-
-	mutex_exit(&(table->autoinc_mutex));
-
-	return(value);
-}
-
-/************************************************************************
-Peeks the autoinc counter value, 0 if not yet initialized. Does not
-increment the counter. The read not protected by any mutex! */
-
-ib_longlong
-dict_table_autoinc_peek(
-/*====================*/
-				/* out: value of the counter */
-	dict_table_t*	table)	/* in: table */
-{
-	ib_longlong	value;
-
 	if (!table->autoinc_inited) {
 
 		value = 0;
@@ -527,7 +467,7 @@ dict_table_autoinc_peek(
 }
 
 /************************************************************************
-Updates the autoinc counter if the value supplied is equal or bigger than the
+Updates the autoinc counter if the value supplied is greater than the
 current value. If not inited, does nothing. */
 
 void
@@ -537,15 +477,21 @@ dict_table_autoinc_update(
 	dict_table_t*	table,	/* in: table */
 	ib_longlong	value)	/* in: value which was assigned to a row */
 {
-	mutex_enter(&(table->autoinc_mutex));
+	if (table->autoinc_inited && value > table->autoinc) {
 
-	if (table->autoinc_inited) {
-		if (value >= table->autoinc) {
-			table->autoinc = value + 1;
-		}
+		table->autoinc = value;
 	}
+}
+
+/************************************************************************
+Release the autoinc lock.*/
 
-	mutex_exit(&(table->autoinc_mutex));
+void
+dict_table_autoinc_unlock(
+/*======================*/
+	dict_table_t*	table)	/* in: release autoinc lock for this table */
+{
+	mutex_exit(&table->autoinc_mutex);
 }
 
 /************************************************************************

dict/dict0mem.c

@@ -90,6 +90,11 @@ dict_mem_table_create(
 	mutex_create(&table->autoinc_mutex, SYNC_DICT_AUTOINC_MUTEX);
 
 	table->autoinc_inited = FALSE;
+
+	/* The actual increment value will be set by MySQL, we simply
+	default to 1 here.*/
+	table->autoinc_increment = 1;
+
 #ifdef UNIV_DEBUG
 	table->magic_n = DICT_TABLE_MAGIC_N;
 #endif /* UNIV_DEBUG */

handler/ha_innodb.h

@@ -32,7 +32,10 @@ typedef struct st_innobase_share {
 } INNOBASE_SHARE;
 
 
+struct dict_index_struct;
 struct row_prebuilt_struct;
+
+typedef struct dict_index_struct dict_index_t;
 typedef struct row_prebuilt_struct row_prebuilt_t;
 
 /* The class defining a handle to an Innodb table */
@@ -70,6 +73,11 @@ class ha_innobase: public handler
 	int change_active_index(uint keynr);
 	int general_fetch(uchar* buf, uint direction, uint match_mode);
 	int innobase_read_and_init_auto_inc(longlong* ret);
+	ulong innobase_autoinc_lock();
+	ulong innobase_set_max_autoinc(ulonglong auto_inc);
+	ulong innobase_reset_autoinc(ulonglong auto_inc);
+	ulong innobase_get_auto_increment(ulonglong* value);
+	dict_index_t* innobase_get_index(uint keynr);
 
 	/* Init values for the class: */
  public:

include/dict0dict.h

@@ -171,6 +171,13 @@ dict_col_name_is_reserved(
 				/* out: TRUE if name is reserved */
 	const char*	name);	/* in: column name */
 /************************************************************************
+Acquire the autoinc lock.*/
+
+void
+dict_table_autoinc_lock(
+/*====================*/
+	dict_table_t*	table);	/* in: table */
+/************************************************************************
 Initializes the autoinc counter. It is not an error to initialize an already
 initialized counter. */
 
@@ -180,22 +187,6 @@ dict_table_autoinc_initialize(
 	dict_table_t*	table,	/* in: table */
 	ib_longlong	value);	/* in: next value to assign to a row */
 /************************************************************************
-Gets the next autoinc value (== autoinc counter value), 0 if not yet
-initialized. If initialized, increments the counter by 1. */
-
-ib_longlong
-dict_table_autoinc_get(
-/*===================*/
-				/* out: value for a new row, or 0 */
-	dict_table_t*	table);	/* in: table */
-/************************************************************************
-Decrements the autoinc counter value by 1. */
-
-void
-dict_table_autoinc_decrement(
-/*=========================*/
-	dict_table_t*	table);	/* in: table */
-/************************************************************************
 Reads the next autoinc value (== autoinc counter value), 0 if not yet
 initialized. */
 
@@ -205,15 +196,6 @@ dict_table_autoinc_read(
 				/* out: value for a new row, or 0 */
 	dict_table_t*	table);	/* in: table */
 /************************************************************************
-Peeks the autoinc counter value, 0 if not yet initialized. Does not
-increment the counter. The read not protected by any mutex! */
-
-ib_longlong
-dict_table_autoinc_peek(
-/*====================*/
-				/* out: value of the counter */
-	dict_table_t*	table);	/* in: table */
-/************************************************************************
 Updates the autoinc counter if the value supplied is equal or bigger than the
 current value. If not inited, does nothing. */
 
@@ -223,6 +205,13 @@ dict_table_autoinc_update(
 
 	dict_table_t*	table,	/* in: table */
 	ib_longlong	value);	/* in: value which was assigned to a row */
+/************************************************************************
+Release the autoinc lock.*/
+
+void
+dict_table_autoinc_unlock(
+/*======================*/
+	dict_table_t*	table);	/* in: table */
 /**************************************************************************
 Adds a table object to the dictionary cache. */
 

include/dict0mem.h

@@ -410,6 +410,11 @@ struct dict_table_struct{
 				SELECT MAX(auto inc column) */
 	ib_longlong	autoinc;/* autoinc counter value to give to the
 				next inserted row */
+
+	ib_longlong	autoinc_increment;
+				/* The increment step of the auto increment
+				column. Value must be greater than or equal
+				to 1 */
 #ifdef UNIV_DEBUG
 	ulint		magic_n;/* magic number */
 # define DICT_TABLE_MAGIC_N	76333786

include/row0mysql.h

@@ -670,6 +670,7 @@ struct row_prebuilt_struct {
 					to this heap */
 	mem_heap_t*	old_vers_heap;	/* memory heap where a previous
 					version is built in consistent read */
+	ulonglong	last_value;	/* last value of AUTO-INC interval */
 	ulint		magic_n2;	/* this should be the same as
 					magic_n */
 };

include/row0sel.h

@@ -171,7 +171,17 @@ row_search_check_if_query_cache_permitted(
 	trx_t*		trx,		/* in: transaction object */
 	const char*	norm_name);	/* in: concatenation of database name,
 					'/' char, table name */
+/***********************************************************************
+Read the max AUTOINC value from an index. */
 
+ulint
+row_search_max_autoinc(
+/*===================*/
+					/* out: DB_SUCCESS if all OK else
+					error code */
+	dict_index_t*	index,		/* in: index to search */
+	const char*	col_name,	/* in: autoinc column name */
+	ib_longlong*	value);		/* out: AUTOINC value read */
 
 /* A structure for caching column values for prefetched rows */
 struct sel_buf_struct{

include/trx0trx.h

@@ -681,6 +681,9 @@ struct trx_struct{
 	trx_undo_arr_t*	undo_no_arr;	/* array of undo numbers of undo log
 					records which are currently processed
 					by a rollback operation */
+	ulint		n_autoinc_rows;	/* no. of AUTO-INC rows required for
+					an SQL statement. This is useful for
+					multi-row INSERTs */
 	/*------------------------------*/
 	char detailed_error[256];	/* detailed error message for last
 					error, or empty. */

row/row0mysql.c

@@ -655,6 +655,8 @@ row_create_prebuilt(
 
 	prebuilt->old_vers_heap = NULL;
 
+	prebuilt->last_value = 0;
+
 	return(prebuilt);
 }
 
@@ -2894,6 +2896,8 @@ row_truncate_table_for_mysql(
 		dict_table_change_id_in_cache(table, new_id);
 	}
 
+	/* MySQL calls ha_innobase::reset_auto_increment() which does
+	the same thing. */
 	dict_table_autoinc_initialize(table, 0);
 	dict_update_statistics(table);
 

row/row0sel.c

@@ -4519,3 +4519,169 @@ row_search_check_if_query_cache_permitted(
 
 	return(ret);
 }
+
+/***********************************************************************
+Read the AUTOINC column from the current row. */
+static
+ib_longlong
+row_search_autoinc_read_column(
+/*===========================*/
+					/* out: value read from the column */
+	dict_index_t*	index,		/* in: index to read from */
+	const rec_t*	rec,		/* in: current rec */
+	ulint		col_no,		/* in: column number */
+	ibool		unsigned_type)	/* in: signed or unsigned flag */
+{
+	ulint		len;
+	byte*		ptr;
+	const byte*	data;
+	ib_longlong	value;
+	mem_heap_t*	heap = NULL;
+	byte		dest[sizeof(value)];
+	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
+	ulint*		offsets	= offsets_;
+
+	*offsets_ = sizeof offsets_ / sizeof *offsets_;
+
+	/* TODO: We have to cast away the const of rec for now.  This needs
+	to be fixed later.*/
+	offsets = rec_get_offsets(
+		(rec_t*) rec, index, offsets, ULINT_UNDEFINED, &heap);
+
+	/* TODO: We have to cast away the const of rec for now.  This needs
+	to be fixed later.*/
+	data = rec_get_nth_field((rec_t*)rec, offsets, col_no, &len);
+
+	ut_a(len != UNIV_SQL_NULL);
+	ut_a(len <= sizeof value);
+
+	/* Convert integer data from Innobase to a little-endian format,
+	sign bit restored to normal */
+
+	for (ptr = dest + len; ptr != dest; ++data) {
+		--ptr;
+		*ptr = *data;
+	}
+
+	if (!unsigned_type) {
+		dest[len - 1] ^= 128;
+	}
+
+	/* The assumption here is that the AUTOINC value can't be negative.*/
+	switch (len) {
+	case 8:
+		value = *(ib_longlong*) ptr;
+		break;
+
+	case 4:
+		value = *(ib_uint32_t*) ptr;
+		break;
+
+	case 2:
+		value = *(uint16 *) ptr;
+		break;
+
+	case 1:
+		value = *ptr;
+		break;
+
+	default:
+		ut_error;
+	}
+
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
+	ut_a(value >= 0);
+
+	return(value);
+}
+
+/***********************************************************************
+Get the last row. */
+static
+const rec_t*
+row_search_autoinc_get_rec(
+/*=======================*/
+					/* out: current rec or NULL */
+	btr_pcur_t*	pcur,		/* in: the current cursor */
+	mtr_t*		mtr)		/* in: mini transaction */
+{
+	do {
+		const rec_t* rec = btr_pcur_get_rec(pcur);
+
+		if (page_rec_is_user_rec(rec)) {
+			return(rec);
+		}
+	} while (btr_pcur_move_to_prev(pcur, mtr));
+
+	return(NULL);
+}
+
+/***********************************************************************
+Read the max AUTOINC value from an index. */
+
+ulint
+row_search_max_autoinc(
+/*===================*/
+					/* out: DB_SUCCESS if all OK else
+					error code, DB_RECORD_NOT_FOUND if
+					column name can't be found in index */
+	dict_index_t*	index,		/* in: index to search */
+	const char*	col_name,	/* in: name of autoinc column */
+	ib_longlong*	value)		/* out: AUTOINC value read */
+{
+	ulint		i;
+	ulint		n_cols;
+	dict_field_t*	dfield = NULL;
+	ulint		error = DB_SUCCESS;
+
+	n_cols = dict_index_get_n_ordering_defined_by_user(index);
+
+	/* Search the index for the AUTOINC column name */
+	for (i = 0; i < n_cols; ++i) {
+		dfield = dict_index_get_nth_field(index, i);
+
+		if (strcmp(col_name, dfield->name) == 0) {
+			break;
+		}
+	}
+
+	*value = 0;
+
+	/* Must find the AUTOINC column name */
+	if (i < n_cols && dfield) {
+		mtr_t		mtr;
+		btr_pcur_t	pcur;
+
+		mtr_start(&mtr);
+
+		/* Open at the high/right end (FALSE), and INIT
+		cursor (TRUE) */
+		btr_pcur_open_at_index_side(
+			FALSE, index, BTR_SEARCH_LEAF, &pcur, TRUE, &mtr);
+
+		if (page_get_n_recs(btr_pcur_get_page(&pcur)) > 0) {
+			const rec_t*	rec;
+
+			rec = row_search_autoinc_get_rec(&pcur, &mtr);
+
+			if (rec != NULL) {
+				ibool unsigned_type = (
+					dfield->col->prtype & DATA_UNSIGNED);
+
+				*value = row_search_autoinc_read_column(
+					index, rec, i, unsigned_type);
+			}
+		}
+
+		btr_pcur_close(&pcur);
+
+		mtr_commit(&mtr);
+	} else {
+		error = DB_RECORD_NOT_FOUND;
+	}
+
+	return(error);
+}

trx/trx0trx.c

@@ -195,6 +195,8 @@ trx_create(
 	memset(&trx->xid, 0, sizeof(trx->xid));
 	trx->xid.formatID = -1;
 
+	trx->n_autoinc_rows = 0;
+
 	trx_reset_new_rec_lock_info(trx);
 
 	return(trx);