Move SafeStackFrameIterator::active_count_ into an isolate.

Move SafeStackFrameIterator::active_count_ into an isolate.

R=ager@chromium.org,vitalyr@chromium.org
BUG=none
TEST=none

Committed: http://code.google.com/p/v8/source/detail?r=7483

[mnaganov (inactive), 2011-04-01 14:52:05]

On 2011/04/01 09:45:14, Mikhail Naganov (Chromium) wrote:

As Vitaly suggested, I've moved variable to Isolate.

[Vitaly Repeshko, 2011-04-01 15:16:37]

LGTM

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc
File src/frames.cc (right):

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc#newcode410
src/frames.cc:410: if (SafeStackFrameIterator::is_active(Isolate::Current()))
Save result of Isolate::Current() as it's used more than once here.

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc#newcode659
src/frames.cc:659: if (SafeStackFrameIterator::is_active(Isolate::Current()) ||
Same here. The second usage is in the HEAP macro.

[mnaganov (inactive), 2011-04-01 15:21:39]

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc
File src/frames.cc (right):

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc#newcode410
src/frames.cc:410: if (SafeStackFrameIterator::is_active(Isolate::Current()))
On 2011/04/01 15:16:37, Vitaly Repeshko wrote:
> Save result of Isolate::Current() as it's used more than once here.

Done.

http://codereview.chromium.org/6771047/diff/1005/src/frames.cc#newcode659
src/frames.cc:659: if (SafeStackFrameIterator::is_active(Isolate::Current()) ||
On 2011/04/01 15:16:37, Vitaly Repeshko wrote:
> Same here. The second usage is in the HEAP macro.

Done.

[Mads Ager (chromium), 2011-04-01 15:27:52]

This looks good to make sure that isolates does not lead to trouble here.

I'm still wondering if there is any way to get preemption during stack frame
iteration? If there is, we need to make sure that this is achieved and restored
with threads in ThreadLocalTop.