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

On Wed, Aug 2, 2017 at 11:47 PM, Noah Misch  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.

-- 
Robert Haas
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