Re: A new function to wait for the backend exit after termination

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
To: "Hou, Zhijie" <houzj.fnst@cn.fujitsu.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Muhammad Usama <m.usama@gmail.com>
Date: 2020-12-03T03:56:08Z
Lists: pgsql-hackers

Attachments

Thanks for the review.

On Thu, Dec 3, 2020 at 7:24 AM Hou, Zhijie <houzj.fnst@cn.fujitsu.com> wrote:
>
> 1.
> +
> +       ereport(WARNING,
> +                       (errmsg("could not wait for the termination of the backend with PID %d within %ld milliseconds",
> +                                       pid, timeout)));
> +
>
> The code use %ld to print int64 type.
> How about use INT64_FORMAT, which looks more appropriate.
>

Changed it to use %lld and typecasting timeout to (long long int) as
suggested by Tom.

>
> 2.
> +       if (timeout <= 0)
> +       {
> +               ereport(WARNING,
> +                               (errmsg("timeout cannot be negative or zero: %ld", timeout)));
> +               PG_RETURN_BOOL(r);
> +       }
>
> The same as 1.
>

Changed.

>
> 3.
> +pg_terminate_backend_and_wait(PG_FUNCTION_ARGS)
> +{
> +       int     pid = PG_GETARG_DATUM(0);
>
> +pg_wait_backend(PG_FUNCTION_ARGS)
> +{
> +       int             pid = PG_GETARG_INT32(0);
>
> The code use different macro to get pid,
> How about use PG_GETARG_INT32(0) for each one.
>

Changed.

> I am Sorry I forgot a possible typo comment.
>
> +{ oid => '16386', descr => 'terminate a backend process and wait for it\'s exit or until timeout occurs'
>
> Does the following change looks better?
>
> Wait for it\'s exit => Wait for its exit
>

Changed.

>
> I changed the status to 'wait on anthor'.
> The others of the patch LGTM,
> I think it can be changed to Ready for Committer again, when this comment is confirmed.
>

Attaching v4 patch. Please have a look.

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Copy-edit text for the pg_terminate_backend() "timeout" parameter.

  2. Remove pg_wait_for_backend_termination().

  3. Add functions to wait for backend termination

  4. Fix typo in comment.