Filter out maps from different global context when collecting type feedback.

Filter out maps from different global context when collecting type feedback.

This avoid leaking memory because optimized code may hold on to maps
from different tabs otherwise.

BUG=v8:1823, 102895
Committed: http://code.google.com/p/v8/source/detail?r=10257

[Vyacheslav Egorov (Chromium), 2011-12-12 13:34:44]

LGTM with comments addressed

Please also add cctest that ensures that we are not leaking memory.

http://codereview.chromium.org/8892002/diff/8001/src/type-info.cc
File src/type-info.cc (right):

http://codereview.chromium.org/8892002/diff/8001/src/type-info.cc#newcode458
src/type-info.cc:458: 
add empty line

http://codereview.chromium.org/8892002/diff/8001/src/type-info.h
File src/type-info.h (right):

http://codereview.chromium.org/8892002/diff/8001/src/type-info.h#newcode259
src/type-info.h:259: static bool InSameContext(Handle<Map> map, Handle<Context>
global_context);
I would better call it: WillRetainDifferentContext or something like this (and
invert true and false) because it returns true if it can't determine context for
example.

This name would also reflect it's purpose (you should also add a comment why
this function&filtering was introduced).

[Vyacheslav Egorov (Chromium), 2011-12-14 13:34:46]

still LGTM

http://codereview.chromium.org/8892002/diff/22001/src/type-info.cc
File src/type-info.cc (right):

http://codereview.chromium.org/8892002/diff/22001/src/type-info.cc#newcode452
src/type-info.cc:452: bool TypeFeedbackOracle::InSameContext(Map* map,
I would call it IsLikelyToRetainOtherContext.

It's very approximate (and can be easily fooled).

[fschneider, 2011-12-14 14:01:42]

http://codereview.chromium.org/8892002/diff/22001/src/type-info.cc
File src/type-info.cc (right):

http://codereview.chromium.org/8892002/diff/22001/src/type-info.cc#newcode452
src/type-info.cc:452: bool TypeFeedbackOracle::InSameContext(Map* map,
On 2011/12/14 13:34:46, Vyacheslav Egorov wrote:
> I would call it IsLikelyToRetainOtherContext.
> 
> It's very approximate (and can be easily fooled).  

Done.