Horton

Re: BUG #18165: Could not duplicate handle for "Global/PostgreSQL.xxxxxxxxxx": Bad file descriptor

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, maxime.boyer@cra-arc.gc.ca, pgsql-bugs@lists.postgresql.org
Date: 2023-10-21T04:10:50Z
Lists: pgsql-bugs 
Ahh, I think I might see it.  "Global/PostgreSQL.2437152779" is an odd
DSM handle (as in, the low order bit is set).  That means that it's a
"main region" DSM segment, of the type that you get if you set
min_dynamic_shared_memory (commit 84b1c63a).  That looks potentially
broken on Windows, because we have this extra NT handle sharing stuff
in dsm_impl_pin_segment(), which can't possibly work and should
probably be gated on !is_main_region_dsm_handle(seg->handle).  On
every other OS that function does nothing, which would explain how we
didn't notice for so long.

Maxime, do you have min_dynamic_shared_memory set?

Commits

  1. Fix min_dynamic_shared_memory on Windows.

  2. Fix huge_pages on Windows

  3. Preallocate some DSM space at startup.