Handle brokered attachment race condition

Handle brokered attachment race condition

In rare cases on OS X with in-process-gpu and zero-copy disabled,
rendering deadlocks can be triggered when a brokered attachment
arrives before the channel reader registers itself as an observer
of the attachment broker.

This patch simply replays unhandled attachment for new observers,
giving them a chance at handling attachments received before they
registered. This is safe since attachments already have unique ids.

BUG=584201
R=erikchen@chromium.org

Committed: https://crrev.com/86a4aa122cb547bf882bcb197c2cd8f4e2852c9d
Cr-Commit-Position: refs/heads/master@{#381691}

[erikchen, 2016-03-16 17:48:18]

erikchen@chromium.org changed reviewers:
+ tsepez@chromium.org

[erikchen, 2016-03-16 17:48:18]

lgtm

+tsepez for OWNER review.

[Tom Sepez, 2016-03-16 18:38:48]

lgtm

[allan.jensen, 2016-03-17 09:53:28]

The CQ bit was checked by allan.jensen@theqtcompany.com

[commit-bot: I haz the power, 2016-03-17 09:53:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1810503002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1810503002/1

[commit-bot: I haz the power, 2016-03-17 11:17:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-17 11:19:20]

Description was changed from

==========
Handle brokered attachment race condition

In rare cases on OS X with in-process-gpu and zero-copy disabled,
rendering deadlocks can be triggered when a brokered attachment
arrives before the channel reader registers itself as an observer
of the attachment broker.

This patch simply replays unhandled attachment for new observers,
giving them a chance at handling attachments received before they
registered. This is safe since attachments already have unique ids.

BUG=584201
R=erikchen@chromium.org
==========

to

==========
Handle brokered attachment race condition

In rare cases on OS X with in-process-gpu and zero-copy disabled,
rendering deadlocks can be triggered when a brokered attachment
arrives before the channel reader registers itself as an observer
of the attachment broker.

This patch simply replays unhandled attachment for new observers,
giving them a chance at handling attachments received before they
registered. This is safe since attachments already have unique ids.

BUG=584201
R=erikchen@chromium.org

Committed: https://crrev.com/86a4aa122cb547bf882bcb197c2cd8f4e2852c9d
Cr-Commit-Position: refs/heads/master@{#381691}
==========

[commit-bot: I haz the power, 2016-03-17 11:19:21]

Patchset 1 (id:??) landed as
https://crrev.com/86a4aa122cb547bf882bcb197c2cd8f4e2852c9d
Cr-Commit-Position: refs/heads/master@{#381691}