code review 75930043: net: avoid multiple calling of syscall connect on Unix ...

net: avoid multiple calling of syscall connect on Unix variants

The previous fix CL 69340044 still leaves a possibility of it.
This CL prevents the kernel, especially DragonFly BSD, from
performing unpredictable asynchronous connection establishment
on stream-based transport layer protocol sockets.

Update issue 7541
Update issue 7474

[mikio, 2014-03-14 08:23:43]

Hello jsing@google.com (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go

[mikio, 2014-03-14 08:29:45]

Hi Joel,

Not sure the reason but somehow removing the second connect syscall
makes dragonfly a bit predictable. So let's take Plan B (as you
mentioned).

[jsing, 2014-03-25 11:49:41]

LGTM

Presuming that it has been tested on various platforms.

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go
File src/pkg/net/fd_unix.go (right):

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:81: case syscall.EINPROGRESS, syscall.EALREADY,
syscall.EINTR:
Nit: This may be more readable with this as the first case (i.e. first case is
do nothing, second is return nil, third is return err).

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:111: switch err = syscall.Errno(nerr); err {
You should be able to use := here.

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:114: case syscall.EINPROGRESS, syscall.EALREADY,
syscall.EINTR:
Same here.

[mikio, 2014-03-26 02:43:17]

*** Submitted as https://code.google.com/p/go/source/detail?r=5f662f12d550 ***

net: avoid multiple calling of syscall connect on Unix variants

The previous fix CL 69340044 still leaves a possibility of it.
This CL prevents the kernel, especially DragonFly BSD, from
performing unpredictable asynchronous connection establishment
on stream-based transport layer protocol sockets.

Update issue 7541
Update issue 7474

LGTM=jsing
R=jsing
CC=golang-codereviews
https://codereview.appspot.com/75930043

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go
File src/pkg/net/fd_unix.go (right):

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:81: case syscall.EINPROGRESS, syscall.EALREADY,
syscall.EINTR:
On 2014/03/25 11:49:41, jsing wrote:
> Nit: This may be more readable with this as the first case (i.e. first case is
> do nothing, second is return nil, third is return err).

Done.

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:111: switch err = syscall.Errno(nerr); err {
On 2014/03/25 11:49:41, jsing wrote:
> You should be able to use := here.

Done.

https://codereview.appspot.com/75930043/diff/20002/src/pkg/net/fd_unix.go#new...
src/pkg/net/fd_unix.go:114: case syscall.EINPROGRESS, syscall.EALREADY,
syscall.EINTR:
On 2014/03/25 11:49:41, jsing wrote:
> Same here.

Done.