Horton

Re: pread() and pwrite()

Jesper Pedersen <jesper.pedersen@redhat.com>

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From: Jesper Pedersen <jesper.pedersen@redhat.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>, Magnus Hagander <magnus@hagander.net>
Cc: Oskari Saarenmaa <os@ohmu.fi>, Pg Hackers <pgsql-hackers@postgresql.org>, Tobias Oberstein <tobias.oberstein@gmail.com>
Date: 2018-09-27T14:03:51Z
Lists: pgsql-hackers 
Hi Thomas,

On 9/18/18 9:48 PM, Thomas Munro wrote:
> It certainly wouldn't hurt... but more pressing to get this committed
> would be Windows support IMHO.  I think the thing to do is to open
> files with the FILE_FLAG_OVERLAPPED flag, and then use ReadFile() and
> WriteFile() with an LPOVERLAPPED struct that holds an offset, but I'm
> not sure if I can write that myself.  I tried doing some semi-serious
> Windows development for the fsyncgate patch using only AppVeyor CI a
> couple of weeks ago and it was like visiting the dentist.
> 

Sorry, no idea about this. Maybe Magnus can provide some feedback ?

> On Thu, Sep 6, 2018 at 6:42 AM Jesper Pedersen
>> Once resolved the patch passes make check-world, and a strace analysis
>> shows the associated read()/write() have been turned into
>> pread64()/pwrite64(). All lseek()'s are SEEK_END's.
> 
> Yeah :-) 

Thanks for v5 too.

Best regards,
  Jesper

Commits

  1. Use pg_pread() and pg_pwrite() for data files and WAL.

  2. Provide pg_pread() and pg_pwrite() for random I/O.

  3. Convert some long lists in configure.in to one-line-per-entry style.