Re: GUC patch for Win32 - Mailing list pgsql-patches

From Bruce Momjian
Subject Re: GUC patch for Win32
Date
Msg-id 200305020358.h423wIb16235@candle.pha.pa.us
Whole thread Raw
In response to Re: GUC patch for Win32  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: GUC patch for Win32  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-patches
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > The patch basically writes all modified GUC variables to a binary file
> > that can be read in by newly created exec'ed backends.
>
> Where exactly is the interlock to ensure that the new backend will end up
> with the correct settings if someone is changing the values at about
> the time of the fork?

Postmaster creates a new file, then does rename() to move it to the name
used by the backends.  It can't move it until the file is not in use.

> The relcache code has this problem solved, but I'm unconvinced that GUC
> does.


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