Re: [HACKERS] Optional message to user when terminating/cancellingbackend - Mailing list pgsql-hackers

From Daniel Gustafsson
Subject Re: [HACKERS] Optional message to user when terminating/cancellingbackend
Date
Msg-id 2CA78AE6-ADD7-4218-88D3-BF0D87120A5A@yesql.se
Whole thread Raw
In response to Re: [HACKERS] Optional message to user when terminating/cancelling backend  (Thomas Munro <thomas.munro@enterprisedb.com>)
Responses Re: [HACKERS] Optional message to user when terminating/cancellingbackend  (Daniel Gustafsson <daniel@yesql.se>)
List pgsql-hackers
> On 6 Jul 2018, at 02:18, Thomas Munro <thomas.munro@enterprisedb.com> wrote:
>
> On Fri, Jun 15, 2018 at 9:56 AM, Daniel Gustafsson <daniel@yesql.se> wrote:
>> attached
>
> Hi Daniel,
>
> 6118  --select pg_cancel_backend(pg_backend_pid(), 'it brings on many changes');
> 6119  select pg_cancel_backend(pg_backend_pid(), NULL);
> 6120! ERROR:  canceling statement due to user request
> 6121--- 25,32 ----
> 6122
> 6123  --select pg_cancel_backend(pg_backend_pid(), 'it brings on many changes');
> 6124  select pg_cancel_backend(pg_backend_pid(), NULL);
> 6125!  pg_cancel_backend
> 6126! -------------------
> 6127!  t
>
> Apparently Windows can take or leave it as it pleases.

Well played =)

> https://ci.appveyor.com/project/postgresql-cfbot/postgresql/build/1.0.4488

That reads to me like it’s cancelling another backend than the current one,
which clearly isn’t right as we’re passing pg_backend_pid().  I can’t really
see what Windows specific bug was introduced by this patch though (or well, the
bug exhibits itself on Windows but it may well be generic of course).

Will continue to hunt.

cheers ./daniel

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