auth: Fix very unlikely race condition (sort of) when refreshing token.

auth: Fix very unlikely race condition (sort of) when refreshing token.

Also dedup some code.

R=iannucci@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2956543003
Committed: https://github.com/luci/luci-go/commit/34a3b4f2ab59c6082472e3d880843ba11d3c7243

[Vadim Sh., 2017-06-22 23:56:09]

PTAL

I hope my explanation makes sense.

[iannucci, 2017-06-23 00:06:18]

lgtm

https://codereview.chromium.org/2956543003/diff/1/common/auth/auth.go
File common/auth/auth.go (right):

https://codereview.chromium.org/2956543003/diff/1/common/auth/auth.go#newcode577
common/auth/auth.go:577: tok, err = a.refreshToken(tok, lifetime+5*time.Second)
would it make sense to tie this to the context deadline?

[Vadim Sh., 2017-06-23 00:11:59]

https://codereview.chromium.org/2956543003/diff/1/common/auth/auth.go
File common/auth/auth.go (right):

https://codereview.chromium.org/2956543003/diff/1/common/auth/auth.go#newcode577
common/auth/auth.go:577: tok, err = a.refreshToken(tok, lifetime+5*time.Second)
On 2017/06/23 00:06:18, iannucci wrote:
> would it make sense to tie this to the context deadline?

I don't think if will provide any value. By existing contract, the tokens we
return are allowed to have lifetime that exceeds context deadline (it's just how
the token cache works: if we have a token that lives for 1h, we use it, no
matter what the context deadline is).

So tying min lifetime to the context deadline when refreshing the token will
just be confusing, I think: most of the time returned tokens will greatly
outlive the deadline anyhow.

[Vadim Sh., 2017-06-23 00:40:54]

The CQ bit was checked by vadimsh@chromium.org

[commit-bot: I haz the power, 2017-06-23 00:41:02]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-23 00:53:37]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1498178454655650, "parent_rev":
"d68e694983c84b6dfed7c9eecc3196fadbf1b946", "commit_rev":
"34a3b4f2ab59c6082472e3d880843ba11d3c7243"}

[commit-bot: I haz the power, 2017-06-23 00:53:44]

Description was changed from

==========
auth: Fix very unlikely race condition (sort of) when refreshing token.

Also dedup some code.

R=iannucci@chromium.org
BUG=
==========

to

==========
auth: Fix very unlikely race condition (sort of) when refreshing token.

Also dedup some code.

R=iannucci@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2956543003
Committed:
https://github.com/luci/luci-go/commit/34a3b4f2ab59c6082472e3d880843ba11d3c7243
==========

[commit-bot: I haz the power, 2017-06-23 00:53:45]

Committed patchset #1 (id:1) as
https://github.com/luci/luci-go/commit/34a3b4f2ab59c6082472e3d880843ba11d3c7243