Expose RunsTasksOnCurrentThread through WebTaskRunner

Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.

Committed: https://crrev.com/a1a9a32d4127e9e0b09e0abf0a3b7994bc7d7459
Cr-Commit-Position: refs/heads/master@{#406537}

[tzik, 2016-07-05 13:42:25]

tzik@chromium.org changed reviewers:
+ kinuko@chromium.org

[tzik, 2016-07-05 13:43:09]

tzik@chromium.org changed reviewers:
+ skyostil@chromium.org
- kinuko@chromium.org

[tzik, 2016-07-05 13:43:54]

tzik@chromium.org changed reviewers:
+ kinuko@chromium.org

[tzik, 2016-07-05 13:43:54]

PTAL

[Sami, 2016-07-05 14:02:14]

Looks fine, but could you explain what this will be used for?

[kinuko, 2016-07-05 14:09:20]

Could you explain a little more about how it's going to be used in the issue
description?

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/fetch/ResourceFetcherTest.cpp (right):

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/fetch/ResourceFetcherTest.cpp:59: bool
runsTasksOnCurrentThread() override { return false; }
At a quick glance it feels a bit strange to return false from these mock task
runners...

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/public/p...
File third_party/WebKit/public/platform/WebTaskRunner.h (right):

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/public/p...
third_party/WebKit/public/platform/WebTaskRunner.h:43: // Can be called from any
thread.
This description sounds like a runner is always tied to a thread, while I think
we're in general trying to avoid introducing such assumptions over task runners.
  base's same method has more subtle description, which is still confusing but
trying to avoid introducing strong tie to a thread... probably we should follow
that (or give it a better name).

[tzik, 2016-07-05 15:21:14]

Description was changed from

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner
==========

to

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.
==========

[tzik, 2016-07-05 15:22:40]

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/fetch/ResourceFetcherTest.cpp (right):

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/fetch/ResourceFetcherTest.cpp:59: bool
runsTasksOnCurrentThread() override { return false; }
On 2016/07/05 14:09:19, kinuko wrote:
> At a quick glance it feels a bit strange to return false from these mock task
> runners...

Done.

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/public/p...
File third_party/WebKit/public/platform/WebTaskRunner.h (right):

https://codereview.chromium.org/2123783002/diff/1/third_party/WebKit/public/p...
third_party/WebKit/public/platform/WebTaskRunner.h:43: // Can be called from any
thread.
On 2016/07/05 14:09:19, kinuko wrote:
> This description sounds like a runner is always tied to a thread, while I
think
> we're in general trying to avoid introducing such assumptions over task
runners.
>   base's same method has more subtle description, which is still confusing but
> trying to avoid introducing strong tie to a thread... probably we should
follow
> that (or give it a better name).

Borrowed it from base...

[kinuko, 2016-07-07 01:38:02]

One more question: we have WebThread->isCurrentThread(), but in your use case
it's not sufficient-- is that the case? Are we going to deprecate the other one?

[Sami, 2016-07-07 15:13:15]

On 2016/07/07 01:38:02, kinuko wrote:
> One more question: we have WebThread->isCurrentThread(), but in your use case
> it's not sufficient-- is that the case? Are we going to deprecate the other
one?

Good point -- seems like we would only need one of these. FWIW base has
RunsTasksOnCurrentThread() and BelongsToCurrentThread() which is just an
alias[1] for the former.

[1]
https://cs.chromium.org/chromium/src/base/single_thread_task_runner.h?l=28&gs...

[tzik, 2016-07-15 06:31:40]

No, it's not sufficient.
Since Blink thread has multiple task runners for prioritization, it's useful to
pass WebTaskRunner rather than WebThread to allow a components to post a task.
Such a component doesn't have WebThread to call isCurrentThread() on.

[kinuko, 2016-07-15 06:43:12]

On 2016/07/15 06:31:40, tzik wrote:
> No, it's not sufficient.
> Since Blink thread has multiple task runners for prioritization, it's useful
to
> pass WebTaskRunner rather than WebThread to allow a components to post a task.
> Such a component doesn't have WebThread to call isCurrentThread() on.

Ok... (would be nice to have it in the issue description too)

lgtm

[tzik, 2016-07-19 13:22:43]

Description was changed from

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.
==========

to

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.
==========

[tzik, 2016-07-19 13:22:43]

tzik@chromium.org changed reviewers:
+ alexclarke@chromium.org

[tzik, 2016-07-19 13:23:26]

+alexclarke. Could you review //component/scheduler part?

[alex clarke (OOO till 29th), 2016-07-19 14:12:17]

scheduler/ LGTM

[tzik, 2016-07-19 16:49:02]

The CQ bit was checked by tzik@chromium.org

[commit-bot: I haz the power, 2016-07-19 16:49:35]

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

[commit-bot: I haz the power, 2016-07-19 16:49:37]

This CL has an open dependency (Issue 2126563002 Patch 20001). Please resolve
the dependency and try again.
If you are sure that there is no real dependency, please use one of the options
listed in https://goo.gl/9Es4OR to land the CL.

[tzik, 2016-07-20 07:09:16]

Patchset #5 (id:80001) has been deleted

[tzik, 2016-07-20 07:09:45]

The CQ bit was checked by tzik@chromium.org

[tzik, 2016-07-20 07:09:45]

The patchset sent to the CQ was uploaded after l-g-t-m from kinuko@chromium.org,
alexclarke@chromium.org
Link to the patchset: https://codereview.chromium.org/2123783002/#ps100001
(title: "rebase")

[commit-bot: I haz the power, 2016-07-20 07:10:03]

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, 2016-07-20 13:03:50]

Description was changed from

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.
==========

to

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.
==========

[commit-bot: I haz the power, 2016-07-20 13:03:52]

Committed patchset #5 (id:100001)

[commit-bot: I haz the power, 2016-07-20 13:04:01]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-07-20 13:05:43]

Description was changed from

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.
==========

to

==========
Expose RunsTasksOnCurrentThread through WebTaskRunner

RunsTasksOnCurrentThread will be used by assertions in tasks that checks
if it runs on the correct thread. WebTaskRunner itself will use it in
the following CL.

Blink code starts using per-frame WebTaskRunner rather than global
WebThread-associated TaskRunner. RunTasksOnCurrentThread is a missing
functionality to migrate from thread-based task scheduling to TaskRunner
based scheduling.

Committed: https://crrev.com/a1a9a32d4127e9e0b09e0abf0a3b7994bc7d7459
Cr-Commit-Position: refs/heads/master@{#406537}
==========

[commit-bot: I haz the power, 2016-07-20 13:05:45]

Patchset 5 (id:??) landed as
https://crrev.com/a1a9a32d4127e9e0b09e0abf0a3b7994bc7d7459
Cr-Commit-Position: refs/heads/master@{#406537}