BUG#5390 - problems with merge tables (ab16adb7) · Commits · Software / OSDI20 Artifacts / mariadb

sql/lock.cc

+65 −84

Original line number	Diff line number	Diff line
		@@ -499,112 +499,91 @@ MYSQL_LOCK mysql_lock_merge(MYSQL_LOCK a,MYSQL_LOCK *b)
		NOTE
		This is mainly meant for MERGE tables in INSERT ... SELECT
		situations. The 'real', underlying tables can be found only after
		the table is opened. The easier way is to check this after the
		tables are locked.
		the MERGE tables are opened. This function assumes that the tables are
		already locked.

		Temporary tables are ignored here like they are ignored in
		get_lock_data(). If we allow two opens on temporary tables later,
		both functions should be checked.

		RETURN
		1 A table from 'tables' matches a lock on 'table'.
		0 No duplicate lock is present.
		-1 Error.
		NULL No duplicate lock found.
		! NULL First table from 'haystack' that matches a lock on 'needle'.
		*/

		TABLE_LIST mysql_lock_have_duplicate(THD thd, TABLE_LIST *needle,
		TABLE_LIST *haystack)
		{
		uint count;
		uint dup_pos;
		TABLE write_lock_used; / dummy */
		TABLE **tables1;
		TABLE **tables2;
		TABLE **table_ptr;
		TABLE_LIST *tlist_ptr;
		MYSQL_LOCK *sql_lock1;
		MYSQL_LOCK *sql_lock2;
		THR_LOCK_DATA **lock_data1;
		THR_LOCK_DATA **end_data1;
		MYSQL_LOCK *mylock;
		TABLE **lock_tables;
		TABLE *table;
		TABLE *table2;
		THR_LOCK_DATA **lock_locks;
		THR_LOCK_DATA **table_lock_data;
		THR_LOCK_DATA **end_data;
		THR_LOCK_DATA **lock_data2;
		THR_LOCK_DATA **end_data2;
		THR_LOCK *lock1;
		DBUG_ENTER("mysql_lock_have_duplicate");

		/* Table may not be defined for derived or view tables. */
		if (! needle->table)
		DBUG_RETURN(NULL);
		if (! (table= needle->table))
		goto end;

		/* Get lock(s) for needle. */
		tables1= &needle->table;
		if (! (sql_lock1= get_lock_data(thd, tables1, 1, 1, &write_lock_used)))
		goto err0;

		/* Count real tables in list. */
		count=0;
		for (tlist_ptr = haystack; tlist_ptr; tlist_ptr= tlist_ptr->next_global)
		if (! tlist_ptr->placeholder() && ! tlist_ptr->schema_table)
		count++;
		/* Allocate a table array. */
		if (! (tables2= (TABLE*) sql_alloc(sizeof(TABLE) * count)))
		goto err1;
		table_ptr= tables2;
		/* Assign table pointers. */
		for (tlist_ptr = haystack; tlist_ptr; tlist_ptr= tlist_ptr->next_global)
		if (! tlist_ptr->placeholder() && ! tlist_ptr->schema_table)
		*(table_ptr++)= tlist_ptr->table;
		/* Get lock(s) for haystack. */
		if (! (sql_lock2= get_lock_data(thd, tables2, count, 1, &write_lock_used)))
		goto err1;

		/* Initialize duplicate position to an impossible value. */
		dup_pos= UINT_MAX;
		/*
		Find a duplicate lock.
		In case of merge tables, sql_lock1 can have more than 1 lock.
		*/
		for (lock_data1= sql_lock1->locks,
		end_data1= lock_data1 + sql_lock1->lock_count;
		lock_data1 < end_data1;
		lock_data1++)
		{
		lock1= (*lock_data1)->lock;
		for (lock_data2= sql_lock2->locks,
		end_data2= lock_data2 + sql_lock2->lock_count;
		/* A temporary table does not have locks. */
		if (table->s->tmp_table == TMP_TABLE)
		goto end;

		/* Get command lock or LOCK TABLES lock. Maybe empty for INSERT DELAYED. */
		if (! (mylock= thd->lock ? thd->lock : thd->locked_tables))
		goto end;

		/* If we have less than two tables, we cannot have duplicates. */
		if (mylock->table_count < 2)
		goto end;

		lock_locks= mylock->locks;
		lock_tables= mylock->table;

		/* Prepare table related variables that don't change in loop. */
		DBUG_ASSERT(table == lock_tables[table->lock_position]);
		table_lock_data= lock_locks + table->lock_data_start;
		end_data= table_lock_data + table->lock_count;

		for (; haystack; haystack= haystack->next_global)
		{
		if (haystack->placeholder() \|\| haystack->schema_table)
		continue;
		table2= haystack->table;
		if (table2->s->tmp_table == TMP_TABLE)
		continue;

		/* All tables in list must be in lock. */
		DBUG_ASSERT(table2 == lock_tables[table2->lock_position]);

		for (lock_data2= lock_locks + table2->lock_data_start,
		end_data2= lock_data2 + table2->lock_count;
		lock_data2 < end_data2;
		lock_data2++)
		{
		if ((*lock_data2)->lock == lock1)
		{
		DBUG_PRINT("ingo", ("duplicate lock found"));
		/* Change duplicate position to the real value. */
		dup_pos= lock_data2 - sql_lock2->locks;
		goto end;
		}
		}
		}
		THR_LOCK_DATA **lock_data;
		THR_LOCK lock2= (lock_data2)->lock;

		end:
		tlist_ptr= NULL; /* In case that no duplicate was found. */
		if (dup_pos != UINT_MAX)
		{
		/* Duplicate found. Search the matching TABLE_LIST object. */
		count= 0;
		for (tlist_ptr = haystack; tlist_ptr; tlist_ptr= tlist_ptr->next_global)
		for (lock_data= table_lock_data;
		lock_data < end_data;
		lock_data++)
		{
		if (! tlist_ptr->placeholder() && ! tlist_ptr->schema_table)
		if ((*lock_data)->lock == lock2)
		{
		count+= tlist_ptr->table->file->lock_count();
		if (count > dup_pos)
		break;
		DBUG_PRINT("info", ("haystack match: '%s'", haystack->table_name));
		DBUG_RETURN(haystack);
		}
		}
		}
		}
		my_free((gptr) sql_lock2, MYF(0));
		my_free((gptr) sql_lock1, MYF(0));
		DBUG_RETURN(tlist_ptr);

		err1:
		my_free((gptr) sql_lock1, MYF(0));
		err0:
		/* This non-null but special value indicates error, if caller cares. */
		DBUG_RETURN(needle);
		end:
		DBUG_PRINT("info", ("no duplicate found"));
		DBUG_RETURN(NULL);
		}


		@@ -693,6 +672,8 @@ static MYSQL_LOCK get_lock_data(THD thd, TABLE **table_ptr, uint count,
		for (i=0 ; i < count ; i++)
		{
		TABLE *table;
		enum thr_lock_type lock_type;

		if ((table=table_ptr[i])->s->tmp_table == TMP_TABLE)
		continue;
		lock_type= table->reginfo.lock_type;

sql/table.h

+6 −11

Original line number	Diff line number	Diff line
		@@ -235,14 +235,9 @@ struct st_table {
		timestamp_auto_set_type timestamp_field_type;
		table_map map; /* ID bit of table (1,2,4,8,16...) */

		uint next_number_index;
		uint blob_ptr_size; /* 4 or 8 */
		uint next_number_key_offset;
		uint lock_position; /* Position in MYSQL_LOCK.table */
		uint lock_data_start; /* Start pos. in MYSQL_LOCK.locks */
		uint lock_count; /* Number of locks */
		int current_lock; /* Type of lock on table */
		enum tmp_table_type tmp_table;
		uint tablenr,used_fields;
		uint temp_pool_slot; /* Used by intern temp tables */
		uint status; /* What's in record[0] */