On Fri, Jan 6, 2012 at 6:13 AM, Magnus Hagander <mag...@hagander.net> wrote:
> On Thu, Jan 5, 2012 at 23:19, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Magnus Hagander <mag...@hagander.net> writes: > >> On Thu, Jan 5, 2012 at 17:13, Tom Lane <t...@sss.pgh.pa.us> wrote: > >>> I think link(2) would create race conditions of its own. I'd be > >>> inclined to suggest that maybe we should just special-case a zero > length > >>> postmaster.pid file as meaning "okay to proceed". In general, garbage > > > >> That's pretty much what I meant - but with a warning message. > > > > Actually ... wait a minute. If we allow that, don't we create a race > > condition between two postmasters starting at almost the same instant? > > The second one could see the lock file when the first has created but > > not yet filled it. > > Good point, yeah, it should do that. But I still think it's rare > enough that just special-casing the error message should be enough... > > so just something that does like stat(filename, &st); size = st.st_size; if (size == 0) elog(ERROR, "lock file \"%s\" has 0 length.", filename); somewhere in CreateLockFile in miscinit.c?
