Horton

Re: BUG #16161: pg_ctl stop fails sometimes (on Windows)

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

View thread View on postgr.es
From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: exclusion@gmail.com
Cc: tgl@sss.pgh.pa.us, pgsql-bugs@lists.postgresql.org
Date: 2019-12-20T03:32:37Z
Lists: pgsql-bugs 
At Fri, 20 Dec 2019 05:40:00 +0300, Alexander Lakhin <exclusion@gmail.com> wrote in 
> 19.12.2019 23:09, Tom Lane wrote:
> > Alexander Lakhin <exclusion@gmail.com> writes:
> >> Maybe we should change the condition to 'if (stat(fileName, &st) != 0 &&
> >> (err = GetLastError()) == ERROR_ACCESS_DENIED)' to avoid unnecessary
> >> sleep with a loop iteration...
> > Well, we have to loop back on file-not-found too ...
> I think, if the file is not found on stat() we can safely return the
> updated err (set errno with _dosmapper(err), to be exact). If we'll loop
> back, we'll get the same err = GetLastError() after next CreateFile().

I think Tom is mentinoing for O_CREAT case. If CreateFile returned
ERROR_ACCESS_DENIED, then stat() returns ERROR_FILE_NOT_FOUND, it
means the next CreateFile can success.

> >> It seems that the check for ERROR_DELETE_PENDING was added to
> >> pgwin32_safestat() blindly, the issue wasn't reproduced at that time:
> >> https://www.postgresql.org/message-id/CAB7nPqRJV6trFta-Qzgi6j2feuYR2ZC%2BKHvWdHnbpDG2scTrxw%40mail.gmail.com
> > Hmm, makes one wonder whether that's actually live code.
> I'll try to research this matter meantime.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. In pgwin32_open, loop after ERROR_ACCESS_DENIED only if we can't stat.

  2. On Windows, wait a little to see if ERROR_ACCESS_DENIED goes away.