POSIX: Add a macro for handling EINTR.

POSIX: Add a macro for handling EINTR.

Previously, our handling of EINTR was a little sloppy. If I happened
to review a bit of code, I probably made sure that EINTR was handled
in a do loop. Otherwise, it would just be ignored.

This patch adds "base/eintr_wrappers.h" which, currenly, defines a
single macro: HANDLE_EINTR. This macro can be wrapped around any
system call and will restart the call if it returns -1 and errno ==
EINTR.

[tony, 2009-04-30 22:25:30]

LGTM, just a small nit.

http://codereview.chromium.org/100225/diff/31/34
File base/eintr_wrappers.h (right):

http://codereview.chromium.org/100225/diff/31/34#newcode1
Line 1: #ifndef BASE_EINTR_WRAPPERS_H_
Nit: Needs copyright and maybe a one sentence comment describing what this file
is for.

[Mark Mentovai, 2009-04-30 22:27:20]

http://codereview.chromium.org/100225/diff/31/34
File base/eintr_wrappers.h (right):

http://codereview.chromium.org/100225/diff/31/34#newcode1
Line 1: #ifndef BASE_EINTR_WRAPPERS_H_
Needs a boilerplate.

http://codereview.chromium.org/100225/diff/31/34#newcode2
Line 2: #define BASE_EINTR_WRAPPERS_H_
Are you gonna add more macros or something here?  wrappers (plural) seems weird
with just this one wrapper.

http://codereview.chromium.org/100225/diff/31/34#newcode10
Line 10: #define HANDLE_EINTR(x) ({ \
Comment might be nice.

http://codereview.chromium.org/100225/diff/31/34#newcode14
Line 14: } while (x == -1 && errno == EINTR); \
Don't you mean ret and not x?

[agl, 2009-04-30 22:39:01]

http://codereview.chromium.org/100225/diff/31/34
File base/eintr_wrappers.h (right):

http://codereview.chromium.org/100225/diff/31/34#newcode2
Line 2: #define BASE_EINTR_WRAPPERS_H_
On 2009/04/30 22:27:20, Mark Mentovai wrote:
> Are you gonna add more macros or something here?  wrappers (plural) seems
weird
> with just this one wrapper.

I suspected that there would be more, but it seems we're doing ok with just the
one. If it gets past the try bots and everything looks good then I'll probably
rename it to remove the s.

http://codereview.chromium.org/100225/diff/31/34#newcode14
Line 14: } while (x == -1 && errno == EINTR); \
On 2009/04/30 22:27:20, Mark Mentovai wrote:
> Don't you mean ret and not x?

Good point! Thanks!