Re: [HACKERS] Optional message to user when terminating/cancelling backend

> On 24 Jul 2018, at 22:57, Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
>
>> On 6 Jul 2018, at 02:18, Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> wrote:
>>
>> On Fri, Jun 15, 2018 at 9:56 AM, Daniel Gustafsson <daniel(at)yesql(dot)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.

Seems the build of the updated patch built and tested Ok. Still have no idea
why the previous one didn’t.

https://ci.appveyor.com/project/postgresql-cfbot/postgresql/build/1.0.6695

cheers ./daniel