[heap] Fix PagedSpace::SizeOfObjects calling from within FreeList::Allocate

[heap] Fix PagedSpace::SizeOfObjects calling from within FreeList::Allocate

Not resetting the allocation area after freeing it potentially results in
negative SizeOfObjects() because the area is accounted for as allocated while it
has already been freed.

BUG=

Committed: https://crrev.com/f5b1409f5fa8776589d952aa71e5929cd5bbd0e1
Cr-Commit-Position: refs/heads/master@{#30928}

[Michael Lippautz, 2015-09-24 16:23:26]

The CQ bit was checked by mlippautz@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-09-24 16:23:37]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1364303002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1364303002/1

[Michael Lippautz, 2015-09-24 16:39:53]

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

[Michael Lippautz, 2015-09-24 16:39:54]

SizeOfObjects was sometimes negative since we did not reset the linear
allocation area after freeing it.

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc
File src/heap/spaces.cc (right):

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc#newcode2391
src/heap/spaces.cc:2391:
owner_->heap()->incremental_marking()->OldSpaceStep(size_in_bytes -
SizeOfObjects() > 0 is a condition to start incremental marking here, which
means that we sometimes didn't start it where we could have.

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc#newcode2551
src/heap/spaces.cc:2551: CHECK_GE(size, 0);
If possible, I'd like to keep this here to catch potential bugs.

[commit-bot: I haz the power, 2015-09-24 16:47:43]

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

[commit-bot: I haz the power, 2015-09-24 16:47:44]

Dry run: This issue passed the CQ dry run.

[Hannes Payer (out of office), 2015-09-25 08:33:09]

LGTM

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc
File src/heap/spaces.cc (right):

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc#newcode2391
src/heap/spaces.cc:2391:
owner_->heap()->incremental_marking()->OldSpaceStep(size_in_bytes -
On 2015/09/24 16:39:53, Michael Lippautz wrote:
> SizeOfObjects() > 0 is a condition to start incremental marking here, which
> means that we sometimes didn't start it where we could have.

Good catch!

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc#newcode2551
src/heap/spaces.cc:2551: CHECK_GE(size, 0);
On 2015/09/24 16:39:54, Michael Lippautz wrote:
> If possible, I'd like to keep this here to catch potential bugs.

I guess a DCHECK would be sufficient. If you keep the CHECK, you should watch
the next canaries that ship with it. As you like.

[Michael Lippautz, 2015-09-25 09:05:17]

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc
File src/heap/spaces.cc (right):

https://codereview.chromium.org/1364303002/diff/1/src/heap/spaces.cc#newcode2551
src/heap/spaces.cc:2551: CHECK_GE(size, 0);
On 2015/09/25 08:33:08, Hannes Payer wrote:
> On 2015/09/24 16:39:54, Michael Lippautz wrote:
> > If possible, I'd like to keep this here to catch potential bugs.
> 
> I guess a DCHECK would be sufficient. If you keep the CHECK, you should watch
> the next canaries that ship with it. As you like.

Let's make it a DCHECK for now as I am anyways testing a lot in this area.

[Michael Lippautz, 2015-09-25 09:05:32]

The CQ bit was checked by mlippautz@chromium.org

[Michael Lippautz, 2015-09-25 09:05:32]

The patchset sent to the CQ was uploaded after l-g-t-m from hpayer@chromium.org
Link to the patchset: https://codereview.chromium.org/1364303002/#ps20001
(title: "CHECK -> DCHECK")

[commit-bot: I haz the power, 2015-09-25 09:05:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1364303002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1364303002/20001

[commit-bot: I haz the power, 2015-09-25 09:28:00]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-25 09:28:17]

Patchset 2 (id:??) landed as
https://crrev.com/f5b1409f5fa8776589d952aa71e5929cd5bbd0e1
Cr-Commit-Position: refs/heads/master@{#30928}