Modify the Weak Reference Set creation API to make it easier to create

Modify the Weak Reference Set creation API to make it easier to create
these sets in the GC Prologue code.

When this new API is not used in dartium:
  Without prolog callbacks in New  gen GC:
    dom-modify createElement runs-per-second 260.94890510948903
    dom-modify createTextNode runs-per-second 172.0

  With prolog callbacks in New  gen GC:
    dom-modify createElement runs-per-second 316.0
    dom-modify createTextNode runs-per-second 197.60479041916167


When this new API is used in dartium:
  Without prolog callbacks in New  gen GC:
    dom-modify createElement runs-per-second 310.0
    dom-modify createTextNode runs-per-second 174.4765702891326

  With prolog callbacks in New  gen GC:
    dom-modify createElement runs-per-second 416.0
    dom-modify createTextNode runs-per-second 241.75824175824175

R=iposva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=35215

[Ivan Posva, 2014-04-17 23:47:44]

As discussed this can be further simplified.

-Ivan

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api.h
File runtime/include/dart_api.h (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api...
runtime/include/dart_api.h:536: * \returns a handle to the weak reference set
builder if successful.
Please name this something else as this is really not a handle.

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api...
runtime/include/dart_api.h:625: DART_EXPORT Dart_Handle
Dart_RegisterWeakReferenceSet(
As discussed this can be entirely removed. Just creating a new set should
register it.

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/gc_marker.cc
File runtime/vm/gc_marker.cc (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/gc_marker.cc#...
runtime/vm/gc_marker.cc:377: break;
Please add a comment that this break is breaking out of the loop iterating over
the weak reference values in the set and not out of the overall handling.

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/scavenger.cc#...
runtime/vm/scavenger.cc:530: break;
ditto

[siva, 2014-04-21 18:04:14]

Addressed comments, PTAL.

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api.h
File runtime/include/dart_api.h (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api...
runtime/include/dart_api.h:536: * \returns a handle to the weak reference set
builder if successful.
s/handle/pointer/

On 2014/04/17 23:47:44, Ivan Posva wrote:
> Please name this something else as this is really not a handle.

https://codereview.chromium.org/238063011/diff/80001/runtime/include/dart_api...
runtime/include/dart_api.h:625: DART_EXPORT Dart_Handle
Dart_RegisterWeakReferenceSet(
On 2014/04/17 23:47:44, Ivan Posva wrote:
> As discussed this can be entirely removed. Just creating a new set should
> register it.

Done.

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/gc_marker.cc
File runtime/vm/gc_marker.cc (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/gc_marker.cc#...
runtime/vm/gc_marker.cc:377: break;
On 2014/04/17 23:47:44, Ivan Posva wrote:
> Please add a comment that this break is breaking out of the loop iterating
over
> the weak reference values in the set and not out of the overall handling.

Done.

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/238063011/diff/80001/runtime/vm/scavenger.cc#...
runtime/vm/scavenger.cc:530: break;
On 2014/04/17 23:47:44, Ivan Posva wrote:
> ditto

Done.

[Ivan Posva, 2014-04-21 18:14:14]

LGTMwC

-Ivan

https://codereview.chromium.org/238063011/diff/110001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/238063011/diff/110001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:542: // All weak reference sets are zone allocated and
unmarked references on
Maybe add an assert that the weak reference sets are empty once we are done?

[siva, 2014-04-21 18:28:53]

https://codereview.chromium.org/238063011/diff/110001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/238063011/diff/110001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:542: // All weak reference sets are zone allocated and
unmarked references on
On 2014/04/21 18:14:14, Ivan Posva wrote:
> Maybe add an assert that the weak reference sets are empty once we are done?

Done.

[siva, 2014-04-21 18:31:22]

Committed patchset #8 manually as r35215 (presubmit successful).