Re: [HACKERS] intermittent failures in Cygwin from select_parallel tests

On Thu, Aug 03, 2017 at 10:45:50AM -0400, Robert Haas wrote:
> On Wed, Aug 2, 2017 at 11:47 PM, Noah Misch <noah@leadboat.com> wrote:
> > postmaster algorithms rely on the PG_SETMASK() calls preventing that.  Without
> > such protection, duplicate bgworkers are an understandable result.  I caught
> > several other assertions; the PMChildFlags failure is another case of
> > duplicate postmaster children:
> >
> >       6 TRAP: FailedAssertion("!(entry->trans == ((void *)0))", File: "pgstat.c", Line: 871)
> >       3 TRAP: FailedAssertion("!(PMSignalState->PMChildFlags[slot] == 1)", File: "pmsignal.c", Line: 229)
> >      20 TRAP: FailedAssertion("!(RefCountErrors == 0)", File: "bufmgr.c", Line: 2523)
> >      21 TRAP: FailedAssertion("!(vmq->mq_sender == ((void *)0))", File: "shm_mq.c", Line: 221)
> >      Also, got a few "select() failed in postmaster: Bad address"
> >
> > I suspect a Cygwin signals bug.  I'll try to distill a self-contained test
> > case for the Cygwin hackers.  The lack of failures on buildfarm member brolga
> > argues that older Cygwin is not affected.
> 
> Nice detective work.

Thanks.  http://marc.info/?t=150183296400001 has my upstream report.  The
Cygwin project lead reproduced this, but a fix remained elusive.

I guess we'll ignore weird postmaster-associated lorikeet failures for the
foreseeable future.