Message-ID: <014768ed-8b39-c44f-b07c-098c87b1644c@gmail.com>
Date: Fri, 1 Dec 2023 17:00:01 +0300
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Subject: Re: Refactoring backend fork+exec code
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To: Heikki Linnakangas <hlinnaka@iki.fi>, Tristan Partin <tristan@neon.tech>,
 Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>,
 Thomas Munro <thomas.munro@gmail.com>
References: <7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi>
 <20230710225043.svl7fqxecwshwc7a@awork3.anarazel.de>
 <119551e6-60f6-49b2-ae04-a382a89f900c@iki.fi>
 <e0dcfabb-f59a-45e8-bd92-f8d706c92128@iki.fi>
 <CXCDA9YFDZS1.Y5JUZBHLLXYR@neon.tech>
 <3b02a5a1-81ea-44e4-a09e-c0a594a4cef8@iki.fi>
From: Alexander Lakhin <exclusion@gmail.com>
In-Reply-To: <3b02a5a1-81ea-44e4-a09e-c0a594a4cef8@iki.fi>
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Hello Heikki,

01.12.2023 15:10, Heikki Linnakangas wrote:
> Attached is new version of these patches. For easier review, I made the new refactorings compared in a new commit 
> 0003. I will squash that before pushing, but this makes it easier to see what changed.
>
> Barring any new feedback or issues, I will commit these.
>

Maybe you could look at issues with running `make check` under Valgrind
when server built with CPPFLAGS="-DUSE_VALGRIND -DEXEC_BACKEND":
# +++ regress check in src/test/regress +++
# initializing database system by copying initdb template
# postmaster failed, examine ".../src/test/regress/log/postmaster.log" for the reason
Bail out!make[1]: ***

...
2023-12-01 16:48:39.136 MSK postmaster[1307988] LOG:  listening on Unix socket "/tmp/pg_regress-pPFNk0/.s.PGSQL.55312"
==00:00:00:01.692 1259396== Syscall param write(buf) points to uninitialised byte(s)
==00:00:00:01.692 1259396==    at 0x5245A37: write (write.c:26)
==00:00:00:01.692 1259396==    by 0x51BBF6C: _IO_file_write@@GLIBC_2.2.5 (fileops.c:1180)
==00:00:00:01.692 1259396==    by 0x51BC84F: new_do_write (fileops.c:448)
==00:00:00:01.692 1259396==    by 0x51BC84F: _IO_new_file_xsputn (fileops.c:1254)
==00:00:00:01.692 1259396==    by 0x51BC84F: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1196)
==00:00:00:01.692 1259396==    by 0x51B1056: fwrite (iofwrite.c:39)
==00:00:00:01.692 1259396==    by 0x552E21: internal_forkexec (postmaster.c:4518)
==00:00:00:01.692 1259396==    by 0x5546A1: postmaster_forkexec (postmaster.c:4444)
==00:00:00:01.692 1259396==    by 0x55471C: StartChildProcess (postmaster.c:5275)
==00:00:00:01.692 1259396==    by 0x557B61: PostmasterMain (postmaster.c:1454)
==00:00:00:01.692 1259396==    by 0x472136: main (main.c:198)
==00:00:00:01.692 1259396==  Address 0x1ffeffdc11 is on thread 1's stack
==00:00:00:01.692 1259396==  in frame #4, created by internal_forkexec (postmaster.c:4482)
==00:00:00:01.692 1259396==

With memset(param, 0, sizeof(*param)); added at the beginning of
save_backend_variables(), server starts successfully, but then
`make check` fails with other Valgrind error.

Best regards,
Alexander