RE: [PATCH] memory leak in ecpglib

Dear Zhang,

Sorry for my late reply.
I'm now planning to refactor this functionality:
https://www.postgresql.org/message-id/OSAPR01MB20048298F882D25897C6AB23F5EF0@OSAPR01MB2004.jpnprd01.prod.outlook.com

If DECLARE STATEMENT and other related statements are enabled only preprocessing process, this problem will be easily
solved.

How about it?

Hayato Kuroda
Fujitsu LIMITED


-----Original Message-----
From: Zhang, Jie/张 杰 
Sent: Tuesday, June 11, 2019 5:14 PM
To: Kuroda, Hayato/�\田 隼人 <kuroda.hayato@fujitsu.com>; Matsumura, Ryo/松村 量 <matsumura.ryo@jp.fujitsu.com>;
pgsql-hackers@lists.postgresql.org
Subject: RE: [PATCH] memory leak in ecpglib

Hi Kuroda,

>If your patch is committed, in your example, any operation for cur1 will not be accepted.
Although the return value after calling ecpg_get_con_name_by_cursor_name(cur1) is NULL,
in ecpg_get_connection(), actual_connection will be returned.
so, operation for cur1 will be accepted,

>p = ecpg_find_declared_statement(declared_name);
>if (p && p->cursor_name == cursor_name)
>p->cursor_name = ecpg_strdup(cursor_name, lineno);
Because the initial value of p->cursor_name is NULL, p->cursor_name will never be updated.

Best Regards!

-----Original Message-----
From: Kuroda, Hayato/�\田 隼人 
Sent: Tuesday, June 11, 2019 2:36 PM
To: Zhang, Jie/张 杰 <zhangjie2@cn.fujitsu.com>; Matsumura, Ryo/松村 量 <matsumura.ryo@jp.fujitsu.com>;
pgsql-hackers@lists.postgresql.org
Subject: RE: [PATCH] memory leak in ecpglib

Dear Zhang,

# I resend the email

Thank you for reporting a bug. I didn't care about this case.

>> We should free p->cursor_name before p->cursor_name = 
>> ecpg_strdup(cursor_name, lineno).

I'm wondering whether this approach is correct or not.
If your patch is committed, in your example, any operation for cur1 will not be accepted.

My idea is changing ecpg_update_declare_statement() for permitting one-to-many relation between a declared name and
cursors.
An example is as below:

p = ecpg_find_declared_statement(declared_name);
if (p && p->cursor_name == cursor_name)
p->cursor_name = ecpg_strdup(cursor_name, lineno);

Do you have any suggestions or comments for this?

Best Regards,
Hayato Kuroda
Fujitsu LIMITED