code review 5494061: net, syscall, os: set CLOEXEC flag on epoll/kqueue desc...

net, syscall, os: set CLOEXEC flag on epoll/kqueue descriptor
Enable new test in os.

[dave_cheney.net, 2011-12-17 02:48:13]

http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go
File src/pkg/net/fd_linux.go (right):

http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go#newco...
src/pkg/net/fd_linux.go:50: syscall.CloseOnExec(p.epfd)
If you are calling epoll_create1 with EPOLL_CLOEXEC above, why do you need to
also call syscall.CloseOnExec as well ?

[iant2, 2011-12-17 05:48:29]

dave@cheney.net writes:

> http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go
> File src/pkg/net/fd_linux.go (right):
>
>
http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go#newco...
> src/pkg/net/fd_linux.go:50: syscall.CloseOnExec(p.epfd)
> If you are calling epoll_create1 with EPOLL_CLOEXEC above, why do you
> need to also call syscall.CloseOnExec as well ?

I only syscall.CloseOnExec in the case where epoll_create1 fails with an
ENOSYS error.  epoll_create1 was added around Linux version 2.6.27, and
I'm not sure we want to fail on earlier versions.  When epoll_create1
fails with ENOSYS, I call epoll_create and then CloseOnExec.

Ian

[dave_cheney.net, 2011-12-17 05:54:31]

My mistake, I missed that part of the logic.

LGTM.

On Sat, Dec 17, 2011 at 4:48 PM, Ian Lance Taylor <iant@google.com> wrote:
> dave@cheney.net writes:
>
>> http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go
>> File src/pkg/net/fd_linux.go (right):
>>
>>
http://codereview.appspot.com/5494061/diff/2001/src/pkg/net/fd_linux.go#newco...
>> src/pkg/net/fd_linux.go:50: syscall.CloseOnExec(p.epfd)
>> If you are calling epoll_create1 with EPOLL_CLOEXEC above, why do you
>> need to also call syscall.CloseOnExec as well ?
>
> I only syscall.CloseOnExec in the case where epoll_create1 fails with an
> ENOSYS error.  epoll_create1 was added around Linux version 2.6.27, and
> I'm not sure we want to fail on earlier versions.  When epoll_create1
> fails with ENOSYS, I call epoll_create and then CloseOnExec.
>
> Ian

[iant, 2011-12-19 20:10:42]

Hello dave@cheney.net, iant@google.com (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[rsc, 2011-12-19 20:16:51]

LGTM

[iant, 2011-12-19 20:57:59]

*** Submitted as http://code.google.com/p/go/source/detail?r=be47ea17bea0 ***

net, syscall, os: set CLOEXEC flag on epoll/kqueue descriptor
Enable new test in os.

R=dave, iant, rsc
CC=golang-dev
http://codereview.appspot.com/5494061