collectAllGarbage(): bail on reaching fixed point.

collectAllGarbage(): bail on reaching fixed point.

To root out objects that become unreachable and dead once persistent
references to them are finalized, we're forced to iteratively GC when
wanting to sweep out all garbage. But no need to continue doing it
after the live object set has stabilized.

R=haraken
BUG=420515
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=193682

[sof, 2015-04-13 15:25:27]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-04-13 15:25:28]

Please take a look.

[haraken, 2015-04-13 23:12:11]

haraken@chromium.org changed reviewers:
+ haraken@chromium.org

[haraken, 2015-04-13 23:12:12]

LGTM

https://codereview.chromium.org/1079993002/diff/1/Source/platform/heap/Heap.cpp
File Source/platform/heap/Heap.cpp (right):

https://codereview.chromium.org/1079993002/diff/1/Source/platform/heap/Heap.c...
Source/platform/heap/Heap.cpp:2402: size_t liveObjects =
Heap::estimatedLiveObjectSize();

Shall we use Heap::markedObjectSize()?

Conceptually Heap::estimatedLiveObjectSize() is a size calculated based on
Heap::markedObjectSize() with some heuristics.

[sof, 2015-04-14 06:40:51]

Not exhaustive, but few tests required more than two GCs to settle. Not
encountered any above three.

https://codereview.chromium.org/1079993002/diff/1/Source/platform/heap/Heap.cpp
File Source/platform/heap/Heap.cpp (right):

https://codereview.chromium.org/1079993002/diff/1/Source/platform/heap/Heap.c...
Source/platform/heap/Heap.cpp:2402: size_t liveObjects =
Heap::estimatedLiveObjectSize();
On 2015/04/13 23:12:12, haraken wrote:
> 
> Shall we use Heap::markedObjectSize()?
> 
> Conceptually Heap::estimatedLiveObjectSize() is a size calculated based on
> Heap::markedObjectSize() with some heuristics.

ok, let's leave estimatedLiveObjectSize() for the ThreadState shouldGC
predicates only to use.

[sof, 2015-04-14 06:40:59]

The CQ bit was checked by sigbjornf@opera.com

[sof, 2015-04-14 06:41:00]

The patchset sent to the CQ was uploaded after l-g-t-m from haraken@chromium.org
Link to the patchset: https://codereview.chromium.org/1079993002/#ps20001
(title: "use markedObjectSize()")

[commit-bot: I haz the power, 2015-04-14 06:41:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1079993002/20001

[commit-bot: I haz the power, 2015-04-14 10:35:28]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=193682