Horton

Re: Unportable implementation of background worker start

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: remi_zara@mac.com
Cc: Andres Freund <andres@anarazel.de>, cm@enterprisedb.com, Alvaro Herrera <alvherre@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2017-04-24T23:47:09Z
Lists: pgsql-hackers 
I wrote:
> What I'm inclined to do is to revert the pselect change but not the other,
> to see if that fixes these two animals.  If it does, we could look into
> blacklisting these particular platforms when choosing pselect.

It looks like coypu is going to need manual intervention (ie, kill -9
on the leftover postmaster) to get unwedged :-(.  That's particularly
disturbing because it implies that ServerLoop isn't iterating at all;
otherwise, it'd have noticed by now that the buildfarm script deleted
its data directory out from under it.  Even if NetBSD's pselect had
forgotten to unblock signals, you'd figure it'd time out after a
minute ... so it's even more broken than that.

			regards, tom lane

Commits

  1. Cope with glibc too old to have epoll_create1().

  2. Make latch.c more paranoid about child-process cases.

  3. Allow multiple bgworkers to be launched per postmaster iteration.

  4. Revert "Use pselect(2) not select(2), if available, to wait in postmaster's loop."

  5. Use pselect(2) not select(2), if available, to wait in postmaster's loop.

  6. Run the postmaster's signal handlers without SA_RESTART.

  7. Fix postmaster's handling of fork failure for a bgworker process.

  8. Partially revert commit 536d47bd9d5fce8d91929bee3128fa1d08dbcc57.

  9. Avoid depending on non-POSIX behavior of fcntl(2).

  10. Remove long-obsolete catering for platforms without F_SETFD/FD_CLOEXEC.