Re: BUG #16154: pg_ctl restart with a logfile fails sometimes (on Windows)

06.12.2019 18:14, Tom Lane wrote:
> Alexander Lakhin <exclusion(at)gmail(dot)com> writes:
>> If this file is still opened by the previous server shell (it can happen
>> when the previous server instance has unlinked it's pid file, but it's
>> CMD shell is still running), the next CMD start fails with the
>> aforementioned error message.
> Interesting. I wonder whether this explains all of the remaining
> buildfarm failures of this sort that we've been seeing even after
> 0ba06e0bf.
>
>> To fix this issue I propose the attached patch
>> (fix_logfile_sharing_violation ).
> This seems like a pretty ugly hack ... please at least make it
> #ifdef WIN32, so that the rest of us don't have to deal with it.
> Also, if I read it correctly, it causes a pre-existing logfile
> to get truncated, which has never happened before. Mode "a"
> would be a better choice.
This change should go under the following code:
#else                            /* WIN32 */

    /*
     * As with the Unix case, it's easiest to use the shell (CMD.EXE) to
     * handle redirection etc.  Unfortunately CMD.EXE lacks any
equivalent of
     * "exec", so we don't get to find out the postmaster's PID immediately.
     */
    PROCESS_INFORMATION pi;
    const char *comspec;

    /* Find CMD.EXE location using COMSPEC, if it's set */
    comspec = getenv("COMSPEC");
    if (comspec == NULL)
        comspec = "CMD";

So it should affect only Windows.
I've fixed the mode. Thanks for your review!

Best regards,
Alexander