code review 8011043: net: fix test data corruption in repetitive test runs b...

net: fix test data corruption in repetitive test runs by -cpu

This CL avoids test data sharing in repetitive test runs;
e.g., go test net -cpu=1,1,1

[albert.strasheim, 2013-03-25 09:40:46]

LGTM

Applying this patch seems to fix things.

Without the patch, I can reproduce the problem with:

go test net -cpu=1,1,1 -v -run=TestResolveIPAddr

The linux/amd64 machine I'm running the tests on has ipv6.disable=1, so maybe
that made a difference?

[mikio, 2013-03-25 09:53:47]

On Mon, Mar 25, 2013 at 6:40 PM,  <fullung@gmail.com> wrote:

> go test net -cpu=1,1,1 -v -run=TestResolveIPAddr
>
> The linux/amd64 machine I'm running the tests on has ipv6.disable=1, so
> maybe that made a difference?

Ah, thanks. I tried -cpu=n instead of cpu=n,m and that's the key to repro.

[mikio, 2013-03-25 11:32:41]

Hello golang-dev@googlegroups.com, fullung@gmail.com (cc:
golang-dev@googlegroups.com),

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

[mikio, 2013-03-25 11:38:03]

PTAL

simplifies test code.

[albert.strasheim, 2013-03-25 11:40:37]

LGTM

someone else should probably also take a look

[bradfitz, 2013-03-25 15:38:45]

https://codereview.appspot.com/8011043/diff/10001/src/pkg/net/ipraw_test.go
File src/pkg/net/ipraw_test.go (right):

https://codereview.appspot.com/8011043/diff/10001/src/pkg/net/ipraw_test.go#n...
src/pkg/net/ipraw_test.go:47: resolveIPAddrTests = append(resolveIPAddrTests,
[]resolveIPAddrTest{
so you're growing the number of tests each time? If -cpu=1,1,1,1,1,1,1 the final
test run will have 7 copies of this test?

could you do this in an init func between "var resolveIPAddrTests" and "func
TestResolveIPAddr" ?

[mikio, 2013-03-26 02:19:37]

PTAL

https://codereview.appspot.com/8011043/diff/10001/src/pkg/net/ipraw_test.go
File src/pkg/net/ipraw_test.go (right):

https://codereview.appspot.com/8011043/diff/10001/src/pkg/net/ipraw_test.go#n...
src/pkg/net/ipraw_test.go:47: resolveIPAddrTests = append(resolveIPAddrTests,
[]resolveIPAddrTest{
On 2013/03/25 15:38:46, bradfitz wrote:
> so you're growing the number of tests each time? If -cpu=1,1,1,1,1,1,1 the
final
> test run will have 7 copies of this test?

oops, thanks for your bird-eye view.
i thought i already did allocate tests := resolveIPAddrTests
for repetitive test runs but that didn't happen in the real world,
hm.

> could you do this in an init func between "var resolveIPAddrTests" and "func
> TestResolveIPAddr" ?

done.

[mikio, 2013-03-26 02:19:42]

PTAL

[bradfitz, 2013-03-26 15:24:48]

LGTM

[mikio, 2013-03-26 16:06:58]

*** Submitted as https://code.google.com/p/go/source/detail?r=be1edd532f2d ***

net: fix test data corruption in repetitive test runs by -cpu

This CL avoids test data sharing in repetitive test runs;
e.g., go test net -cpu=1,1,1

R=golang-dev, fullung, bradfitz
CC=golang-dev
https://codereview.appspot.com/8011043