code review 7310096: runtime: ensure forward progress of runtime.Gosched() f...

runtime: ensure forward progress of runtime.Gosched() for locked goroutines
The removed code leads to the situation when M executes the same locked G again and again.
Fixes issue 4820.

[dvyukov, 2013-02-15 15:28:16]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://dvyukov%40google.com@code.google.com/p/go/

[rsc, 2013-02-15 17:16:19]

LGTM, I guess.

As written the test case is too trivial to care (see my comment on issue
4820). If it is a distillation of a real scenario then I would care more.

[dvyukov, 2013-02-15 17:33:32]

On 2013/02/15 17:16:19, rsc wrote:
> LGTM, I guess.
> 
> As written the test case is too trivial to care (see my comment on issue
> 4820). If it is a distillation of a real scenario then I would care more.

The distillation is:
A GUI package uses LockOSThread, and in some callback from the  GUI package you
use some other package that internally waits with Gosched(). Boom!

[dvyukov, 2013-02-15 18:31:22]

*** Submitted as https://code.google.com/p/go/source/detail?r=59da6744d66d ***

runtime: ensure forward progress of runtime.Gosched() for locked goroutines
The removed code leads to the situation when M executes the same locked G again
and again.
Fixes issue 4820.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7310096

[dave_cheney.net, 2013-02-15 22:49:26]

This has caused some build breakage. Would you please consider rolling it back.

On Sat, Feb 16, 2013 at 5:31 AM,  <dvyukov@google.com> wrote:
> *** Submitted as
> https://code.google.com/p/go/source/detail?r=59da6744d66d ***
>
>
> runtime: ensure forward progress of runtime.Gosched() for locked
> goroutines
> The removed code leads to the situation when M executes the same locked
> G again and again.
> Fixes issue 4820.
>
> R=golang-dev, rsc
> CC=golang-dev
> https://codereview.appspot.com/7310096
>
>
>
> https://codereview.appspot.com/7310096/
>
> --
>
> ---You received this message because you are subscribed to the Google Groups
> "golang-dev" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to golang-dev+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>