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Re: [Patch v1 3/3] t5562: replace /dev/zero with a pipe from generate_zero_bytes

From
Junio C Hamano <gitster@pobox.com>
Date
Feb 13, 2019, 17:26 UTC
Message-ID
<xmqqd0nvd2h5.fsf@gitster-ct.c.googlers.com>
In-Reply-To
<f3b506bb-52eb-3a1f-ba3d-0cf327271ab2@kdbg.org>
Johannes Sixt <j6t@kdbg.org> writes:
Show 24 quoted lines
> Am 12.02.19 um 18:24 schrieb Junio C Hamano:
>>>> diff --git a/t/t5562-http-backend-content-length.sh b/t/t5562-http-backend-content-length.sh
>>>> @@ -143,14 +143,14 @@ test_expect_success GZIP 'push gzipped empty' '
>>>>  test_expect_success 'CONTENT_LENGTH overflow ssite_t' '
>>>>         NOT_FIT_IN_SSIZE=$(ssize_b100dots) &&
>>>> -       env \
>>>> +       generate_zero_bytes infinity  | env \
>>>>                 CONTENT_TYPE=application/x-git-upload-pack-request \
>>>>                 QUERY_STRING=/repo.git/git-upload-pack \
>>>>                 PATH_TRANSLATED="$PWD"/.git/git-upload-pack \
>>>>                 GIT_HTTP_EXPORT_ALL=TRUE \
>>>>                 REQUEST_METHOD=POST \
>>>>                 CONTENT_LENGTH="$NOT_FIT_IN_SSIZE" \
>>>> -               git http-backend </dev/zero >/dev/null 2>err &&
>>>> +               git http-backend >/dev/null 2>err &&
>> 
>> Doesn't this "inifinity" mode have the same issue that was worked
>> around by 6129c930 ("test-lib: limit the output of the yes utility",
>> 2016-02-02) on Windows?  If I read correctly, the process upstream
>> of the pipe (in this case, perl producing a stream of infinite NULs)
>> would not die when the downstream stops reading with SIGPIPE.
>
> I think we do not have to worry, and the reason is that the
> justification for 6129c930 is simply wrong.

That's kinda surprising but in a pleasant way---it's good that we have one less thing we need to worry about.

Thanks.
Show 9 quoted lines
>
> As I did not find the patch series discussed here to pull and test, I
> repeated the timing tests with t7610-mergetool.sh with and without
> 6129c930 reverted, and the difference is only in the noise. The reason
> t7610 takes so long on Windows looks more like a consequence of the
> 10,000 processes that it spawns. It is a mystery to me how I came to the
> conclusion that the change in 6129c930 would make a difference. :-(
>
> -- Hannes
Previous: Johannes SixtNext: Max Kirillov
Message 12 of 24 in “2.21.0-rc0 test fixes resulting from use of /dev/zero”
  1. 0/3 2.21.0-rc0 test fixes resulting from use of /dev/zerorandall.s.becker@rogers.com, Feb 9, 2019
  2. 1/3 test-lib-functions.sh: add generate_zero_bytes functionrandall.s.becker@rogers.com, Feb 9, 2019
  3. Eric SunshineFeb 10, 2019
  4. Randall S. BeckerFeb 10, 2019
  5. Jeff KingFeb 12, 2019
  6. Eric SunshineFeb 12, 2019
  7. randall.s.becker@rogers.comFeb 12, 2019
  8. 3/3 t5562: replace /dev/zero with a pipe from generate_zero_bytesrandall.s.becker@rogers.com, Feb 9, 2019
  9. Eric SunshineFeb 10, 2019
  10. Junio C HamanoFeb 12, 2019
  11. Johannes SixtFeb 12, 2019
  12. Junio C HamanoFeb 13, 2019
  13. t5562: do not depend on /dev/zeroMax Kirillov, Feb 15, 2019
  14. Randall S. BeckerFeb 15, 2019
  15. Junio C HamanoFeb 15, 2019
  16. Randall S. BeckerFeb 15, 2019
  17. Junio C HamanoFeb 15, 2019
  18. 2/3 t5318: replace use of /dev/zero with generate_zero_bytesrandall.s.becker@rogers.com, Feb 9, 2019
  19. Eric SunshineFeb 10, 2019
  20. Junio C HamanoFeb 12, 2019
  21. Junio C HamanoFeb 13, 2019
  22. Randall S. BeckerFeb 13, 2019
  23. Junio C HamanoFeb 13, 2019
  24. Randall S. BeckerFeb 13, 2019

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