Use external byte arrays for token stream, this moves the token stream out of the isolate heap. For…

Use external byte arrays for token stream, this moves the token stream out of the isolate heap. For full snapshots the external byte array points to the snapshot buffer thus incurring no extra space in the C heap either.

Heap usage stats before this change is:
New space (0k of 32768k) Old space (1085k of 1280k) Code space (0k of 0k)

Heap Usage stats after this change is:
New space (0k of 32768k) Old space (947k of 1024k) Code space (0k of 0k)

A savings of about 138k.
Committed: https://code.google.com/p/dart/source/detail?r=11977

[hausner, 2012-09-04 17:23:58]

drive-by cheer!

[cshapiro, 2012-09-05 20:33:50]

lgtm

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/object.cc
File vm/object.cc (right):

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/object.cc#newcode4798
vm/object.cc:4798: ::free(peer);
It is always safe to free NULL.  That is a no-op.

[cshapiro, 2012-09-06 00:11:49]

http://codereview.chromium.org/10914050/diff/1/vm/snapshot.cc
File vm/snapshot.cc (right):

http://codereview.chromium.org/10914050/diff/1/vm/snapshot.cc#newcode419
vm/snapshot.cc:419: reinterpret_cast<void*>(array),
make line 419 a NULL instead of non-NULL

[siva, 2012-09-06 18:19:29]

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/object.cc
File vm/object.cc (right):

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/object.cc#newcode4798
vm/object.cc:4798: ::free(peer);
I added the ASSERT more to ensure that this finalizer callback is not registered
for the case when we point
straight to the snapshot read only buffer.

In that case I setup the peer to be NULL and callback to NULL.

On 2012/09/05 20:33:50, cshapiro wrote:
> It is always safe to free NULL.  That is a no-op.

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/snapshot.cc
File vm/snapshot.cc (right):

https://chromiumcodereview.appspot.com/10914050/diff/1/vm/snapshot.cc#newcode419
vm/snapshot.cc:419: reinterpret_cast<void*>(array),
On 2012/09/06 00:11:49, cshapiro wrote:
> make line 419 a NULL instead of non-NULL

Done.