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Re: Make the git codebase thread-safe

From
Karsten Blees <karsten.blees@gmail.com>
Date
Feb 13, 2014, 22:51 UTC
Message-ID
<52FD4C84.7060209@gmail.com>
In-Reply-To
<loom.20140213T193220-631@post.gmane.org>
Am 13.02.2014 19:38, schrieb Zachary Turner:
> The only reason ReOpenFile is necessary at 
> all is because some code somewhere is mixing read-styles against the same 
> fd.
> 
I don't understand...ReadFile with OVERLAPPED parameter doesn't modify the HANDLE's file position, so you should be able to mix read()/pread() however you like (as long as read() is only called from one thread).
I tried without ReOpenFile and it seems to work like a charm, or am I missing something?
----8<----
ssize_t mingw_pread(int fd, void *buf, size_t count, off64_t offset)
{
	DWORD bytes_read;
	OVERLAPPED overlapped;
	memset(&overlapped, 0, sizeof(overlapped));
	overlapped.Offset = (DWORD) offset;
	overlapped.OffsetHigh = (DWORD) (offset >> 32);
	if (!ReadFile((HANDLE) _get_osfhandle(fd), buf, count, &bytes_read,
	    &overlapped)) {
		errno = err_win_to_posix(GetLastError());
		return -1;
	}
	return (ssize_t) bytes_read;
}
Previous: Zachary TurnerNext: Stefan Zager
Message 34 of 55 in “Make the git codebase thread-safe”
  1. Stefan ZagerFeb 12, 2014
  2. Robin H. JohnsonFeb 12, 2014
  3. Duy NguyenFeb 12, 2014
  4. Karsten BleesFeb 12, 2014
  5. Mike HommeyFeb 12, 2014
  6. Karsten BleesFeb 13, 2014
  7. Stefan ZagerFeb 12, 2014
  8. Duy NguyenFeb 12, 2014
  9. Stefan ZagerFeb 12, 2014
  10. Matthieu MoyFeb 12, 2014
  11. Stefan ZagerFeb 12, 2014
  12. David KastrupFeb 12, 2014
  13. Stefan ZagerFeb 12, 2014
  14. David KastrupFeb 12, 2014
  15. Mike HommeyFeb 12, 2014
  16. David KastrupFeb 13, 2014
  17. Mike HommeyFeb 13, 2014
  18. Mike HommeyFeb 13, 2014
  19. David KastrupFeb 13, 2014
  20. Junio C HamanoFeb 12, 2014
  21. Stefan ZagerFeb 12, 2014
  22. Junio C HamanoFeb 12, 2014
  23. Erik Faye-LundFeb 12, 2014
  24. Stefan ZagerFeb 12, 2014
  25. Erik Faye-LundFeb 12, 2014
  26. Stefan ZagerFeb 12, 2014
  27. Erik Faye-LundFeb 12, 2014
  28. Karsten BleesFeb 12, 2014
  29. Stefan ZagerFeb 12, 2014
  30. Johannes SixtFeb 13, 2014
  31. David KastrupFeb 13, 2014
  32. Stefan ZagerFeb 13, 2014
  33. Zachary TurnerFeb 13, 2014
  34. Karsten BleesFeb 13, 2014
  35. Stefan ZagerFeb 13, 2014
  36. Zachary TurnerFeb 13, 2014
  37. Karsten BleesFeb 14, 2014
  38. Stefan ZagerFeb 14, 2014
  39. brian m. carlsonFeb 13, 2014
  40. Matheus TavaresApr 2, 2019
  41. Duy NguyenApr 2, 2019
  42. David KastrupApr 2, 2019
  43. Duy NguyenApr 2, 2019
  44. David KastrupApr 2, 2019
  45. Matheus Tavares BernardinoApr 2, 2019
  46. Zachary TurnerFeb 14, 2014
  47. Karsten BleesFeb 14, 2014
  48. Duy NguyenFeb 15, 2014
  49. Stefan ZagerFeb 15, 2014
  50. Duy NguyenFeb 15, 2014
  51. Zachary TurnerFeb 15, 2014
  52. Duy NguyenFeb 15, 2014
  53. Junio C HamanoFeb 18, 2014
  54. Zachary TurnerFeb 18, 2014
  55. Stefan ZagerFeb 14, 2014

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