[Isolates] Cleanup of codepaths slowing down Dromaeo in browser.

[Isolates] Cleanup of codepaths slowing down Dromaeo in browser.

This is Dromaeo Core numbers, v8 bleeding_edge, isolates and isolates + this patch: http://dromaeo.com/?id=122292,122309,123122

There is more to do in api.cc, especially around things like v8::Null() that pull Isolate multiple times while they don't need to. However, that is more involved change, for another patch.

Committed: http://code.google.com/p/v8/source/detail?r=5941

[Vitaly Repeshko, 2010-11-25 23:04:09]

http://codereview.chromium.org/5107003/diff/1/src/api.cc
File src/api.cc (right):

http://codereview.chromium.org/5107003/diff/1/src/api.cc#newcode520
src/api.cc:520: ASSERT(value->IsHeapObject());
This will break if someone tries to create handle to a v8::Value, e.g.
v8::Integer::New(42). This kind of usage is silly, but we have allowed it so
far. I think, we need to special case non heap objects here.

http://codereview.chromium.org/5107003/diff/1/src/api.cc#newcode522
src/api.cc:522: value, static_cast<i::JSObject*>(value)->GetIsolate()));
JSObject -> HeapObject.

[Dmitry Titov, 2010-12-02 03:55:41]

I think it is ready for another look.

v8::HandleScope::CreateHandle is now templated method. This allows to have
specializations that work via Isolate::Current and HeapObject::GetIsolate, and
avoid extra conditionals and function calls while not bringing anything internal
to v8.h

[Dmitry Titov, 2010-12-02 04:14:28]

Numbers with last patch (bleeding_edge/isolates/isolates_with_patch):
http://dromaeo.com/?id=122292,122309,124374

[Dmitry Titov, 2010-12-07 02:42:51]

Ready for another look. Not sure where Vitaly's previous notes went, here are 2
changes:

1. Removed LOG_FOR_ISOLATE, will try to do that in a separate patch.
2. Removed the templated CreateHandle, used the approach proposed by Vitaly.

[Vitaly Repeshko, 2010-12-07 13:35:13]

LGTM

http://codereview.chromium.org/5107003/diff/21001/include/v8.h
File include/v8.h (right):

http://codereview.chromium.org/5107003/diff/21001/include/v8.h#newcode3514
include/v8.h:3514: T* that_ptr = *that;
Weird indentation.

http://codereview.chromium.org/5107003/diff/21001/src/isolate.h
File src/isolate.h (right):

http://codereview.chromium.org/5107003/diff/21001/src/isolate.h#newcode109
src/isolate.h:109: // TODO(isolates): pass isolate pointer here.
The todo is done!