Message-ID: <5997ff317a5827496537580078bcd19f4441f8d2.camel@crunchydata.com>
Subject: Re: Refactoring backend fork+exec code
From: reid.thompson@crunchydata.com
To: Heikki Linnakangas <hlinnaka@iki.fi>, Andres Freund <andres@anarazel.de>
Cc: Tristan Partin <tristan@neon.tech>, pgsql-hackers
	 <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@gmail.com>
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Date: Mon, 29 Jan 2024 10:54:52 -0500
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On Thu, 2024-01-25 at 01:51 +0200, Heikki Linnakangas wrote:
>=20
> And here we go. BackendID is now a 1-based index directly into the=20
> PGPROC array.
>=20

Would it be worthwhile to also note in this comment FIRST_AUX_PROC's
and IsAuxProcess()'s dependency on B_ARCHIVER and it's location in the
enum table?

      /*                                                                   =
                                                          =20
      =C2=A6* Auxiliary processes. These have PGPROC entries, but they are =
not                                                            =20
      =C2=A6* attached to any particular database. There can be only one of=
 each of                                                       =20
      =C2=A6* these running at a time.                                     =
                                                               =20
      =C2=A6*                                                              =
                                                               =20
      =C2=A6* If you modify these, make sure to update NUM_AUXILIARY_PROCS =
and the                                                        =20
      =C2=A6* glossary in the docs.                                        =
                                                               =20
      =C2=A6*/                                                             =
                                                               =20
      B_ARCHIVER,                                                          =
                                                          =20
      B_BG_WRITER,                                                         =
                                                          =20
      B_CHECKPOINTER,                                                      =
                                                          =20
      B_STARTUP,                                                           =
                                                          =20
      B_WAL_RECEIVER,                                                      =
                                                          =20
      B_WAL_SUMMARIZER,                                                    =
                                                          =20
      B_WAL_WRITER,                                                        =
                                                          =20
  } BackendType;                                                           =
                                                          =20
                                                                           =
                                                        =20
  #define BACKEND_NUM_TYPES (B_WAL_WRITER + 1)                       =20
                                                                           =
                                                          =20
  extern PGDLLIMPORT BackendType MyBackendType;                      =20
                                                                           =
                                                          =20
  #define FIRST_AUX_PROC B_ARCHIVER                                  =20
  #define IsAuxProcess(type)          (MyBackendType >=3D FIRST_AUX_PROC)