Oilpan: add eager tracing stack depth checks.

Oilpan: add eager tracing stack depth checks.

To prevent runaway system stack use due to too eager unrolling of
trace() calls during marking, add tracking of recursive depth and
fall back to using the explicit mark stack if a limit is
exceeded.

Eager tracing isn't currenty enabled by default, so no extra overhead
for Oilpan trunk added. Set ENABLE_EAGER_TRACING_BY_DEFAULT to 1 to
near-universally enable eager tracing.

R=
BUG=420515
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=186553

[haraken, 2014-12-04 15:45:09]

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

[haraken, 2014-12-04 15:45:09]

LGTM

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
File Source/platform/heap/Visitor.h (right):

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:535: // The maximum depth of eager, unrolled
trace() calls that is

is => are

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:539: template<typename U, bool>friend class
DefaultTraceTrait;

Add one space after '>'

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:542: inline void incTraceDepth() {
m_traceDepth++; }

incrementTraceDepth

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:543: inline void decTraceDepth() {
ASSERT(m_traceDepth > 0); m_traceDepth--; }

decrementTraceDepth

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:606: if (visitor->canTraceEagerly()) {

LIKELY just in case? Not sure.

[sof, 2014-12-04 20:15:44]

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
File Source/platform/heap/Visitor.h (right):

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:535: // The maximum depth of eager, unrolled
trace() calls that is
On 2014/12/04 15:45:09, haraken wrote:
> 
> is => are

The maximum depth ... is

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:539: template<typename U, bool>friend class
DefaultTraceTrait;
On 2014/12/04 15:45:09, haraken wrote:
> 
> Add one space after '>'

Done.

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:542: inline void incTraceDepth() {
m_traceDepth++; }
On 2014/12/04 15:45:09, haraken wrote:
> 
> incrementTraceDepth

Done.

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:543: inline void decTraceDepth() {
ASSERT(m_traceDepth > 0); m_traceDepth--; }
On 2014/12/04 15:45:09, haraken wrote:
> 
> decrementTraceDepth

Done.

https://codereview.chromium.org/783513002/diff/20001/Source/platform/heap/Vis...
Source/platform/heap/Visitor.h:606: if (visitor->canTraceEagerly()) {
On 2014/12/04 15:45:09, haraken wrote:
> 
> LIKELY just in case? Not sure.

Good idea; I had that when initially evaluating the cost of this trace depth
check.

[sof, 2014-12-04 22:52:17]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2014-12-04 22:53:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/783513002/80001

[commit-bot: I haz the power, 2014-12-04 23:50:12]

Committed patchset #5 (id:80001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=186553