Re: [bug fix] postgres.exe crashes with access violation on Windows while starting up

On Tue, Oct 31, 2017 at 6:59 AM, Tsunakawa, Takayuki
<tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)com> wrote:
> From: pgsql-hackers-owner(at)postgresql(dot)org
>> [mailto:pgsql-hackers-owner(at)postgresql(dot)org] On Behalf Of Michael Paquier
>> So you are basically ready to lose any message that could be pushed
>> here if there is no memory context? That does not sound like a good
>> trade-off to me. A static buffer does not look like the best idea
>> either to not truncate message, so couldn't we envisage to just use
>> malloc? pgwin32_message_to_UTF16() is called in two places in elog.c,
>> and there is a full control on the error code paths.
>
> Thank you for reviewing a rare bug fix on Windows that most people wouldn't be interested in.

Yeah, it may take a while until a committer gets interested I am
afraid. See my bug about pg_basebackup on Windows with path names..

> When CurrentMemoryContext is NULL, the message is logged with ReportEventA(). This is similar to write_console().

My point is that as Postgres is running as a service, isn't it wrong
to write a message to stderr as a fallback if the memory context is
not set? You would lose a message. It seems to me that for an
operation that can happen at a low-level like the postmaster startup,
we should really use a low-level operation as well.
--
Michael