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Re: [PATCHv3 02/13] xread: poll on non blocking fds

From
Junio C Hamano <gitster@pobox.com>
Date
Sep 23, 2015, 00:43 UTC
Message-ID
<xmqqzj0eynh3.fsf@gitster.mtv.corp.google.com>
In-Reply-To
<CAGZ79kYKxNAXhbmXEtMeBYeGqu8i4bcUW_hpjLaPSF4p5O=uBg@mail.gmail.com>
Stefan Beller <sbeller@google.com> writes:
> We should not care if the call to poll failed, as we're in an infinite loop and
> can only get out with the correct read(..).

I think I agree with that reasoning. The only thing we want out of this call to poll(2) is to delay calling read(2) again when we know we would get EAGAIN again; whether the reason why poll(2) returned is because of some error or because some data has become ready on the file descriptor, we no longer are in that "we know we would get EAGAIN" situation and do want to call read(2), which would return either the right error or perform a successful read to make some progress.

Sounds sensible.
Previous: Stefan BellerNext: Jeff King
Message 13 of 48 in “[PATCHv3 00/13] fetch submodules in parallel and a preview on parallel "submodule update"”
  1. Stefan BellerSep 21, 2015
  2. 01/13 Sending "Fetching submodule <foo>" output to stderrStefan Beller, Sep 21, 2015
  3. Junio C HamanoSep 21, 2015
  4. 02/13 xread: poll on non blocking fdsStefan Beller, Sep 21, 2015
  5. Junio C HamanoSep 21, 2015
  6. Torsten BögershausenSep 22, 2015
  7. Jacob KellerSep 22, 2015
  8. Torsten BögershausenSep 22, 2015
  9. Junio C HamanoSep 22, 2015
  10. Jeff KingSep 22, 2015
  11. Junio C HamanoSep 22, 2015
  12. Stefan BellerSep 23, 2015
  13. Junio C HamanoSep 23, 2015
  14. Jeff KingSep 23, 2015
  15. Eric SunshineSep 21, 2015
  16. Junio C HamanoSep 22, 2015
  17. Stefan BellerSep 22, 2015
  18. Junio C HamanoSep 22, 2015
  19. Stefan BellerSep 22, 2015
  20. 03/13 xread_nonblock: add functionality to read from fds nonblockinglyStefan Beller, Sep 21, 2015
  21. Junio C HamanoSep 22, 2015
  22. Junio C HamanoSep 22, 2015
  23. Jacob KellerSep 22, 2015
  24. Jacob KellerSep 22, 2015
  25. Junio C HamanoSep 22, 2015
  26. 04/13 strbuf: add strbuf_read_once to read without blockingStefan Beller, Sep 21, 2015
  27. Junio C HamanoSep 22, 2015
  28. Jacob KellerSep 22, 2015
  29. 05/13 run-command: factor out return value computationStefan Beller, Sep 21, 2015
  30. Junio C HamanoSep 22, 2015
  31. 06/13 run-command: add an asynchronous parallel child processorStefan Beller, Sep 21, 2015
  32. Junio C HamanoSep 22, 2015
  33. Stefan BellerSep 22, 2015
  34. Junio C HamanoSep 22, 2015
  35. Stefan BellerSep 22, 2015
  36. Junio C HamanoSep 22, 2015
  37. Stefan BellerSep 22, 2015
  38. Junio C HamanoSep 22, 2015
  39. 07/13 fetch_populated_submodules: use new parallel job processingStefan Beller, Sep 21, 2015
  40. Junio C HamanoSep 22, 2015
  41. 08/13 submodules: allow parallel fetching, add tests and documentationStefan Beller, Sep 21, 2015
  42. 09/13 submodule config: keep update strategy aroundStefan Beller, Sep 21, 2015
  43. Eric SunshineSep 22, 2015
  44. Stefan BellerSep 22, 2015
  45. 10/13 git submodule update: cmd_update_recursiveStefan Beller, Sep 21, 2015
  46. 11/13 git submodule update: cmd_update_cloneStefan Beller, Sep 21, 2015
  47. 12/13 git submodule update: cmd_update_fetchStefan Beller, Sep 21, 2015
  48. 13/13 Rewrite submodule update in CStefan Beller, Sep 21, 2015

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