code review 7707047: database/sql: allow simultaneous queries, etc in a Tx

database/sql: allow simultaneous queries, etc in a Tx

Now that revision 0c029965805f is in, it's easy
to guarantee that we never access a driver.Conn
concurrently, per the database/sql/driver contract,
so we can remove this overlarge mutex.

Fixes issue 3857

[bradfitz, 2013-03-18 15:10:04]

Hello golang-dev@googlegroups.com,

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

[adg, 2013-03-18 18:30:39]

LGTM

https://codereview.appspot.com/7707047/diff/4001/src/pkg/database/sql/sql_tes...
File src/pkg/database/sql/sql_test.go (right):

https://codereview.appspot.com/7707047/diff/4001/src/pkg/database/sql/sql_tes...
src/pkg/database/sql/sql_test.go:741: func TestSimultaneousQueries(t *testing.T)
{
If this test fails, does it deadlock?

[bradfitz, 2013-03-18 18:33:07]

On Mon, Mar 18, 2013 at 11:30 AM, <adg@golang.org> wrote:

> LGTM
>
>
> https://codereview.appspot.**com/7707047/diff/4001/src/pkg/**
>
database/sql/sql_test.go<https://codereview.appspot.com/7707047/diff/4001/src/pkg/database/sql/sql_test.go>
> File src/pkg/database/sql/sql_test.**go (right):
>
> https://codereview.appspot.**com/7707047/diff/4001/src/pkg/**
>
database/sql/sql_test.go#**newcode741<https://codereview.appspot.com/7707047/diff/4001/src/pkg/database/sql/sql_test.go#newcode741>
> src/pkg/database/sql/sql_test.**go:741: func TestSimultaneousQueries(t
> *testing.T) {
> If this test fails, does it deadlock?
>

well, crashes with deadlock.

[bradfitz, 2013-03-18 18:39:06]

*** Submitted as https://code.google.com/p/go/source/detail?r=c6f2bdbb0933 ***

database/sql: allow simultaneous queries, etc in a Tx

Now that revision 0c029965805f is in, it's easy
to guarantee that we never access a driver.Conn
concurrently, per the database/sql/driver contract,
so we can remove this overlarge mutex.

Fixes issue 3857

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/7707047

[adg, 2013-03-18 21:17:10]

On 19 March 2013 05:33, Brad Fitzpatrick <bradfitz@golang.org> wrote:

> well, crashes with deadlock.


Yep that's what I thought. SGTM