Function PAR_reserving

src/gpre/par.cpp:1071–1132

//

void PAR_reserving( USHORT flags, bool parse_sql)
{
	gpre_dbb* database;

	while (true)
	{
		// find a relation name, or maybe a list of them

		if (!parse_sql && terminator())
			break;

		do {
			gpre_rel* relation = EXP_relation();
			if (!relation)
				CPR_s_error("relation name");
			database = relation->rel_database;
			rrl* lock_block = (rrl*) MSC_alloc(RRL_LEN);
			lock_block->rrl_next = database->dbb_rrls;
			lock_block->rrl_relation = relation;
			database->dbb_rrls = lock_block;
		} while (MSC_match(KW_COMMA));

		// get the lock level and mode and apply them to all the
		// relations in the list

		MSC_match(KW_FOR);
		USHORT lock_level = (flags & TRA_con) ? isc_tpb_protected : isc_tpb_shared;
		USHORT lock_mode = isc_tpb_lock_read;

		if (MSC_match(KW_PROTECTED))
			lock_level = isc_tpb_protected;
		else if (MSC_match(KW_EXCLUSIVE))
			lock_level = isc_tpb_exclusive;
		else if (MSC_match(KW_SHARED))
			lock_level = isc_tpb_shared;

		if (MSC_match(KW_WRITE))
		{
			if (flags & TRA_ro)
				CPR_error("write lock requested for a read_only transaction");
			lock_mode = isc_tpb_lock_write;
		}
		else
			MSC_match(KW_READ);

		for (database = gpreGlob.isc_databases; database; database = database->dbb_next)
		{
			for (rrl* lock_block = database->dbb_rrls; lock_block; lock_block = lock_block->rrl_next)
			{
				if (!lock_block->rrl_lock_level)
				{
					fb_assert(lock_level <= MAX_UCHAR);
					fb_assert(lock_mode <= MAX_UCHAR);
					lock_block->rrl_lock_level = (UCHAR) lock_level;
					lock_block->rrl_lock_mode = (UCHAR) lock_mode;
				}
			}
		}