Enable V8 idle tasks.

Enable V8 idle tasks.

Enables posting of idle tasks, via the blink scheduler, which notify V8 of idle
time when it can perform GC work.

BUG=421880
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=183888

[rmcilroy, 2014-10-10 15:31:24]

rmcilroy@chromium.org changed reviewers:
+ jochen@chromium.org

[rmcilroy, 2014-10-10 15:31:24]

Jochen, could you please take a look, thanks.

Manfred / Hannes FYI.

[jochen (gone - plz use gerrit), 2014-10-13 08:06:22]

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
File Source/bindings/core/v8/V8Initializer.cpp (right):

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:199: // TODO: Change V8's API to take
a deadline - http://crbug.com/417668
blink has FIXME: instead of TODO

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:202: if (idleTimeInMillis > 0) {
no { } required

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:202: if (idleTimeInMillis > 0) {
no { } required

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:206: postIdleGCTaskMainThread();
how will you make sure that you don't end up squeezing multiple gc tasks into a
single idle pause.

how will you restart idle notifications once nothing more was to be done?

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
File Source/platform/RuntimeEnabledFeatures.in (right):

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
Source/platform/RuntimeEnabledFeatures.in:143: V8IdleTasks status=stable
Maybe add the feature without a status first, so it doesn't collide with the
tasks from the compositor?

then you can change the chromium side to enable the feature at the same time the
compositor idle notifications are disabled

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
Source/platform/RuntimeEnabledFeatures.in:143: V8IdleTasks status=stable
Maybe add the feature without a status first, so it doesn't collide with the
tasks from the compositor?

then you can change the chromium side to enable the feature at the same time the
compositor idle notifications are disabled

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
Source/platform/RuntimeEnabledFeatures.in:143: V8IdleTasks status=stable
Maybe add the feature without a status first, so it doesn't collide with the
tasks from the compositor?

then you can change the chromium side to enable the feature at the same time the
compositor idle notifications are disabled

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
Source/platform/RuntimeEnabledFeatures.in:143: V8IdleTasks status=stable
maybe first add the feature without a status, so it doesn't collide with the
notifications from the compositor?

[rmcilroy, 2014-10-13 11:22:08]

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
File Source/bindings/core/v8/V8Initializer.cpp (right):

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:199: // TODO: Change V8's API to take
a deadline - http://crbug.com/417668
On 2014/10/13 08:06:20, jochen wrote:
> blink has FIXME: instead of TODO

Done.

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:202: if (idleTimeInMillis > 0) {
On 2014/10/13 08:06:20, jochen wrote:
> no { } required

Done.

https://codereview.chromium.org/639773007/diff/1/Source/bindings/core/v8/V8In...
Source/bindings/core/v8/V8Initializer.cpp:206: postIdleGCTaskMainThread();
On 2014/10/13 08:06:20, jochen wrote:
> how will you make sure that you don't end up squeezing multiple gc tasks into
a
> single idle pause.

CL https://codereview.chromium.org/640053003/ deals with this - it ensures that
only tasks posted before the current idle period will execute during the current
idle period.

> how will you restart idle notifications once nothing more was to be done?

This is what we will need to work out.  Is there any bottleneck on starting JS
execution which we could use for this?

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
File Source/platform/RuntimeEnabledFeatures.in (right):

https://codereview.chromium.org/639773007/diff/1/Source/platform/RuntimeEnabl...
Source/platform/RuntimeEnabledFeatures.in:143: V8IdleTasks status=stable
On 2014/10/13 08:06:21, jochen wrote:
> Maybe add the feature without a status first, so it doesn't collide with the
> tasks from the compositor?
> 
> then you can change the chromium side to enable the feature at the same time
the
> compositor idle notifications are disabled

Sure that makes sense - done.

[rmcilroy, 2014-10-13 18:35:25]

Patchset #4 (id:120001) has been deleted

[jochen (gone - plz use gerrit), 2014-10-14 13:32:54]

lgtm

[rmcilroy, 2014-10-17 10:51:38]

The CQ bit was checked by rmcilroy@chromium.org

[commit-bot: I haz the power, 2014-10-17 10:52:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/639773007/90001

[commit-bot: I haz the power, 2014-10-17 10:55:44]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-17 10:55:45]

Try jobs failed on following builders:
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/69969)

[rmcilroy, 2014-10-17 11:15:09]

The CQ bit was checked by rmcilroy@chromium.org

[commit-bot: I haz the power, 2014-10-17 11:15:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/639773007/180001

[commit-bot: I haz the power, 2014-10-17 13:33:46]

Committed patchset #4 (id:180001) as 183888