[heap] Implement concurrent marking boilerplate.

[heap] Implement concurrent marking boilerplate.

This patch adds a trivial ConcurrentMarking class that can start
background tasks.

BUG=chromium:694255
Review-Url: https://codereview.chromium.org/2728363002
Cr-Commit-Position: refs/heads/master@{#43615}
Committed: https://chromium.googlesource.com/v8/v8/+/e96b5ed423bd6c566c1b11d54303c29cdfd473c7

[ulan, 2017-03-06 13:30:59]

ulan@chromium.org changed reviewers:
+ hpayer@chromium.org, mlippautz@chromium.org

[ulan, 2017-03-06 13:31:00]

ptal

[Hannes Payer (out of office), 2017-03-06 13:43:19]

lgtm

https://codereview.chromium.org/2728363002/diff/20001/src/heap/concurrent-mar...
File src/heap/concurrent-marking.h (right):

https://codereview.chromium.org/2728363002/diff/20001/src/heap/concurrent-mar...
src/heap/concurrent-marking.h:22: static const int kMaxNumberOfTasks = 10;
Instead of using a max, let's add a heuristic function that returns an
appropriate number. Similar to parallel compaction.

Maybe, the default should be 1.

[Michael Lippautz, 2017-03-06 13:45:27]

lgtm

[ulan, 2017-03-06 13:52:20]

https://codereview.chromium.org/2728363002/diff/20001/src/heap/concurrent-mar...
File src/heap/concurrent-marking.h (right):

https://codereview.chromium.org/2728363002/diff/20001/src/heap/concurrent-mar...
src/heap/concurrent-marking.h:22: static const int kMaxNumberOfTasks = 10;
On 2017/03/06 13:43:19, Hannes Payer wrote:
> Instead of using a max, let's add a heuristic function that returns an
> appropriate number. Similar to parallel compaction.
> 
> Maybe, the default should be 1.

It's the upper bound on number of tasks. The actual number of tasks will be set
dynamically in StartMarkingTasks. We can start there with 1 or use heuristic.

[ulan, 2017-03-06 14:52:44]

The CQ bit was checked by ulan@chromium.org

[commit-bot: I haz the power, 2017-03-06 14:52:55]

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, 2017-03-06 15:19:37]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1488811964872940,
"parent_rev": "3c63c40f3e61705ced8c4fadd7795eaf0920a9db", "commit_rev":
"e96b5ed423bd6c566c1b11d54303c29cdfd473c7"}

[commit-bot: I haz the power, 2017-03-06 15:19:42]

Description was changed from

==========
[heap] Implement concurrent marking boilerplate.

This patch adds a trivial ConcurrentMarking class that can start
background tasks.

BUG=chromium:694255
==========

to

==========
[heap] Implement concurrent marking boilerplate.

This patch adds a trivial ConcurrentMarking class that can start
background tasks.

BUG=chromium:694255

Review-Url: https://codereview.chromium.org/2728363002
Cr-Commit-Position: refs/heads/master@{#43615}
Committed:
https://chromium.googlesource.com/v8/v8/+/e96b5ed423bd6c566c1b11d54303c29cdfd...
==========

[commit-bot: I haz the power, 2017-03-06 15:19:44]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/e96b5ed423bd6c566c1b11d54303c29cdfd...