Keep (Heap)TerminatedArray in a consistent state while building.

Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698
Committed: https://crrev.com/dbab3f0a4938a7c3bf9ff9d84858e98f2a11a8ee
Cr-Commit-Position: refs/heads/master@{#372367}

[sof, 2016-01-29 15:44:08]

sigbjornf@opera.com changed reviewers:
+ haraken@chromium.org, tkent@chromium.org

[sof, 2016-01-29 15:44:09]

please take a look.

[haraken, 2016-01-29 16:00:32]

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
File third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h (right):

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h:34: m_array =
ArrayType<T>::Allocator::create(m_capacity);

What happens if a conservative GC hits during the Allocator::create?

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h:35: } else {

Add:

  ASSERT(m_array->at(m_count - 1).isLastInArray());

[sof, 2016-01-29 16:28:44]

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
File third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h (right):

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h:34: m_array =
ArrayType<T>::Allocator::create(m_capacity);
On 2016/01/29 16:00:32, haraken wrote:
> 
> What happens if a conservative GC hits during the Allocator::create?

m_array will be empty, so there'll be a null pointer on the stack. Which
wouldn't be traced.

https://codereview.chromium.org/1650123002/diff/1/third_party/WebKit/Source/w...
third_party/WebKit/Source/wtf/TerminatedArrayBuilder.h:35: } else {
On 2016/01/29 16:00:32, haraken wrote:
> 
> Add:
> 
>   ASSERT(m_array->at(m_count - 1).isLastInArray());

Done.

[haraken, 2016-01-29 16:33:54]

LGTM

[sof, 2016-01-29 16:38:19]

Description was changed from

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=
BUG=581698
==========

to

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698
==========

[sof, 2016-01-29 16:38:35]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2016-01-29 16:39:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1650123002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1650123002/20001

[commit-bot: I haz the power, 2016-01-29 17:35:56]

Description was changed from

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698
==========

to

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698
==========

[commit-bot: I haz the power, 2016-01-29 17:35:57]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-29 17:36:50]

Description was changed from

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698
==========

to

==========
Keep (Heap)TerminatedArray in a consistent state while building.

When building a (Heap)TerminatedArray<T>, be careful to always have a
'last marker' set while doing so. Otherwise, should a conservative GC
strike while building, there's no last marker to terminate the tracing
of the HeapTerminatedArray<> elements.

R=haraken
BUG=581698

Committed: https://crrev.com/dbab3f0a4938a7c3bf9ff9d84858e98f2a11a8ee
Cr-Commit-Position: refs/heads/master@{#372367}
==========

[commit-bot: I haz the power, 2016-01-29 17:36:51]

Patchset 2 (id:??) landed as
https://crrev.com/dbab3f0a4938a7c3bf9ff9d84858e98f2a11a8ee
Cr-Commit-Position: refs/heads/master@{#372367}