Debug garbage collector does not correctly remove cross-gen garbage

Debug garbage collector does not correctly remove cross-gen garbage

Modifies the debug garbage collector (CollectAllGarbage()) to correctly
remove inter-generational garbage by evacuating all of new space.

Adds tests to check if this issue has been correctly resolved.

Updates the WeakProperty_PreserveCrossGen test to call for one new and
one old space collection instead of CollectAllGarbage(). Otherwise, all
weak properties are swept as garbage.

DETAILS:

ISSUE

Specifically, the following arrangements in a heap resulted
in garbage surviving a GC.

- Dead object in old space pointing to dead object in new space results
  in the new space object surviving.
  - A cycle between two dead objects, one in each space, results in the
    cycle surviving until all objects are in the old space.

R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/98fe465b8580fe82027d474a04d338850962eb3f

[danunez, 2017-06-30 21:15:13]

Ready for review.

[rmacnak, 2017-06-30 22:24:57]

lgtm w/ comments

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc
File runtime/vm/heap.cc (right):

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode366
runtime/vm/heap.cc:366: 
Two lines between functions (clang-format doesn't handle everything).

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode372
runtime/vm/heap.cc:372: TIMELINE_FUNCTION_GC_DURATION(thread,
"CollectNewGeneration");
"EvacuateNewGeneration"

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode382
runtime/vm/heap.cc:382: 
Two lines

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.h
File runtime/vm/heap.h (right):

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.h#newcode309
runtime/vm/heap.h:309: void EvacuateNewSpaceGarbage(Thread* thread, GCReason
reason);
Consider just "EvacuateNewSpace", since the garbage isn't being evacuated.

Place below the "helper functions" comment

[danunez, 2017-06-30 22:33:58]

Got it. Will land after new patchset is uploaded.

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc
File runtime/vm/heap.cc (right):

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode366
runtime/vm/heap.cc:366: 
On 2017/06/30 22:24:56, rmacnak wrote:
> Two lines between functions (clang-format doesn't handle everything).

Done.

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode372
runtime/vm/heap.cc:372: TIMELINE_FUNCTION_GC_DURATION(thread,
"CollectNewGeneration");
On 2017/06/30 22:24:56, rmacnak wrote:
> "EvacuateNewGeneration"

Done.

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.cc#newcode382
runtime/vm/heap.cc:382: 
On 2017/06/30 22:24:56, rmacnak wrote:
> Two lines

Done.

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.h
File runtime/vm/heap.h (right):

https://codereview.chromium.org/2964503005/diff/1/runtime/vm/heap.h#newcode309
runtime/vm/heap.h:309: void EvacuateNewSpaceGarbage(Thread* thread, GCReason
reason);
On 2017/06/30 22:24:56, rmacnak wrote:
> Consider just "EvacuateNewSpace", since the garbage isn't being evacuated.
> 
> Place below the "helper functions" comment

Done.

[danunez, 2017-06-30 23:03:51]

Description was changed from

==========
Debug garbage collector does not correctly remove cross-gen garbage

Modifies the debug garbage collector (CollectAllGarbage()) to correctly
remove inter-generational garbage by evacuating all of new space.

Adds tests to check if this issue has been correctly resolved.

Updates the WeakProperty_PreserveCrossGen test to call for one new and
one old space collection instead of CollectAllGarbage(). Otherwise, all
weak properties are swept as garbage.

DETAILS:

ISSUE

Specifically, the following arrangements in a heap resulted
in garbage surviving a GC.

- Dead object in old space pointing to dead object in new space results
  in the new space object surviving.
  - A cycle between two dead objects, one in each space, results in the
    cycle surviving until all objects are in the old space.

R=rmacnak@google.com
==========

to

==========
Debug garbage collector does not correctly remove cross-gen garbage

Modifies the debug garbage collector (CollectAllGarbage()) to correctly
remove inter-generational garbage by evacuating all of new space.

Adds tests to check if this issue has been correctly resolved.

Updates the WeakProperty_PreserveCrossGen test to call for one new and
one old space collection instead of CollectAllGarbage(). Otherwise, all
weak properties are swept as garbage.

DETAILS:

ISSUE

Specifically, the following arrangements in a heap resulted
in garbage surviving a GC.

- Dead object in old space pointing to dead object in new space results
  in the new space object surviving.
  - A cycle between two dead objects, one in each space, results in the
    cycle surviving until all objects are in the old space.

R=rmacnak@google.com

Committed:
https://github.com/dart-lang/sdk/commit/98fe465b8580fe82027d474a04d338850962eb3f
==========

[danunez, 2017-06-30 23:03:53]

Committed patchset #2 (id:20001) manually as
98fe465b8580fe82027d474a04d338850962eb3f (presubmit successful).