Re: pipe chunking vs Windows

From: Magnus Hagander <magnus(at)hagander(dot)net>
To: Andrew Dunstan <andrew(at)dunslane(dot)net>
Cc: Andreas Pflug <pgadmin(at)pse-consulting(dot)de>, "korry(dot)douglas" <korry(dot)douglas(at)enterprisedb(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: pipe chunking vs Windows
Date: 2007-07-30 07:57:04
Message-ID: 20070730075704.GC24715@svr2.hagander.net
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On Sun, Jul 29, 2007 at 07:43:34PM -0400, Andrew Dunstan wrote:
>
>
> Andreas Pflug wrote:
> >Andrew Dunstan wrote:
> >
> >>I have no idea why that's done - it goes back to the origins of the
> >>syslogger - probably because someone mistakenly thinks all WIndows
> >>text files have to have CRLF line endings.
> >>
> >>I tried changing that to _O_BINARY, and calling _setmode on both the
> >>pipe before it's duped into stderr and stderr after the dup and both.
> >>Nothing seemed to work.
> >>
> >AFAIR the flag has to be set again in each child process.
> >
> >
>
> OK, this was the bit of info I was missing. I put a call in
> SubPostmasterMain() like this:
>
> _setmode(fileno(stderr), _O_BINARY);
>
> and one in the syslogger code the same, just after the pipe is dup'ed
> into stderr.
>
> After that I saw no more corruption issues.

Seems right - for anything EXEC_BACKEND, if you change a state from the
default it won't be inherited, so you nede to explicitly add it in the
child.

> However, the problem is that in backporting it we'd make a slight
> behaviour change - the log file just gets LF instead of CRLF line
> endings. I'm inclined to say that's a better result than living with the
> bug, though.

Can't we add back the CRLF combo when writing the file out from the
syslogger process?

//Magnus

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