Heap profiler currently gets "document" of global objects while taking snapshot (to later retrieve its "URL"). This is unsafe as there may be no current v8 context when the property is requested while corresponding property accessor may make some assumptions about the context stack during its invokation. Several crashes were reported due to this problem:
https://bugs.webkit.org/show_bug.cgi?id=103076
https://crbug.com/162121
https://crbug.com/132727

This patch adds a callback for resolving global object names and avoid the crashes.
Review URL: https://codereview.chromium.org/11415203

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13137 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10892033

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12410 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=yangguo@chromium.org
BUG=v8:2016, v8:2017
TEST=

Review URL: https://chromiumcodereview.appspot.com/10823034
Patch from James Pike <g00gle@chilon.net>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12199 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: https://chromiumcodereview.appspot.com/10535096

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11793 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10444137

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11702 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

We are pushing stats data as a raw array of uint32_t values at the moment.
It makes tricky the process of updating the API between v8 and WebKit.

BUG=none
TEST=HeapSnapshotObjectsStats

Review URL: https://chromiumcodereview.appspot.com/10110001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11355 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: https://chromiumcodereview.appspot.com/10094011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11339 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The stats data have only count field at the moment.
A constantly growing array of integers also can be a reason of a leak.
Ans we have to have a way to detect such kind of leaks.

Drive by fix:
FindObject and AddEntry were replaced with FindEntry/FindOrAddEntry pair.

BUG=none
TEST=HeapSnapshotObjectsStats

Review URL: https://chromiumcodereview.appspot.com/10086004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11327 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: https://chromiumcodereview.appspot.com/10037004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11315 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The idea is to monitor the heap regulary and track each object in the heap.
With this data we will be able do draw heap usage diagram.
Where X is time and Y is the number of objects.

BUG=none
TEST=HeapSnapshotObjectsStats

Review URL: https://chromiumcodereview.appspot.com/10049002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11302 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

At the moment it is evaluating on the front-end side and this is cost us 2 * (load time + parse time + traverse via snapshot) because I need this value for two previous snapshots.

BUG=none
TEST=test-heap-profiler

Review URL: https://chromiumcodereview.appspot.com/9858016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11161 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Revert "This value is required for showing the heap snapshot delta in Summary view of DevTools.Profiler."

This reverts commit 634864d65ebe820a967f6162d8e226cf4a73e51a.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9861018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11158 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

At the moment it is evaluating on the front-end side and this is cost us 2 * (load time + parse time + traverse via snapshot) because I need this value for two previous snapshots.

BUG=none
TEST=test-heap-profiler

Review URL: https://chromiumcodereview.appspot.com/9858016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11150 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
TEST=test-heap-profiler

Review URL: https://chromiumcodereview.appspot.com/9858010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11145 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

It turns out that an increasing number of persistent handles is a good signal for bugs in the bindings layer

BUG=none
TEST=cctest/test-heap-profiler/PersistentHandleCount

Review URL: https://chromiumcodereview.appspot.com/9620007
Patch from Jochen Eisinger <jochen@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10960 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This patch changes the signature of the v8::HeapGraphNode::GetRetainedSize method, but it's not used in Chromium, and it should be easy for other clients (if any) to adjust to this change.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9466014
Patch from Alexei Filippov <alexeif@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10846 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

As example there are 'Detached DOM Tree' nodes in WebKit. It is very useful to be able to see all such
nodes grouped together. It can be done with help of some post processing but I did this explicitly
on v8 side because it is much faster. At the moment this kind of nodes has kNative type.
I'd like to hide these nodes from the Retainment View but I can filter them only by name.

BUG=none
TEST=HeapSnapshotRetainedObjectInfo

Review URL: https://chromiumcodereview.appspot.com/9323064

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10614 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The detailed heap snapshot has two groups of nodes. The first one
is the group for v8 heap nodes and the second one is the group for
native objects. At the moment we have two different sets of native
objects. There are 'Detached DOM trees' and 'Document DOM trees' type of objects.

I think it'd be nice to replace one group containing all native objects with
separate groups for different types of native objects.

BUG=none
TEST=HeapSnapshotRetainedObjectInfo

Review URL: https://chromiumcodereview.appspot.com/9223009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10528 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

[Fixed the bug revealed by the Win32 bot]

Several changes to better organize snapshot data:

1. Provide information about weak references.
2. Group (GC roots) children.
3. Prettify debug snapshot printing.

BUG=v8:1832
TEST=cctest/test-heap-profiler/*Weak*
TBR=vitalyr@chromium.org

Initial CL: http://codereview.chromium.org/8716009

Review URL: http://codereview.chromium.org/8822019

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Heap profiler tests fail on Win32, need to investigate.

This reverts commit b5374ebd92c11ac4aae16b4e31e54166d406e490.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10162 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Several changes to better organize snapshot data:

1. Provide information about weak references.
2. Group (GC roots) children.
3. Prettify debug snapshot printing.

BUG=v8:1832
TEST=cctest/test-heap-profiler/*Weak*

Review URL: http://codereview.chromium.org/8716009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10158 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This allows getting a heap object by a heap snapshot node for further
inspection. Very useful for objects from bindings that mostly have
getter-provided fields.

R=vegorov@google.com
BUG=webkit/61179
TEST=test-heap-profiler/GetHeapValue,GetHeapValueForDeletedObject

Review URL: http://codereview.chromium.org/8046006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9430 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

2000 LOC are gone!

R=sgjesse@chromium.org
BUG=1481

Review URL: http://codereview.chromium.org/7247018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8406 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This is a preparation for removing aggregated heap snapshots.
W/o this API, counting object instances in a snapshot is very hard.

R=sgjesse@chromium.org
BUG=1481
TEST=cctest/test-heap-profiler/NodesIteration

Review URL: http://codereview.chromium.org/7204040

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8342 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Patch by Nicolas Kaiser <nikai@nikai.net>

R=sgjesse@chromium.org
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/7030008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7891 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Diffs and retaining paths are implemented on JS side. There is no need
to maintain native implementation.

R=vitalyr@chromium.org
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6770009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7412 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=vitalyr@chromium.org
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6685084

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7308 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

objects retained by object groups and global handles.

This information is then used during heap snapshot generation
to provide a more complete memory picture.

This patch will be needed to fix https://bugs.webkit.org/show_bug.cgi?id=53659.

Review URL: http://codereview.chromium.org/6626043

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7125 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

As taking a snapshot of a large heap takes noticeable time, it's
good to be able to monitor and control it.

The change itself is small, big code deletes and additions are in
fact moves. The only significant change is simplification of
approximated retained sizes calculation algorithm.

Review URL: http://codereview.chromium.org/5687003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5978 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TEST=cctest/test-heap-profiler/HeapSnapshotGetNodeById

Review URL: http://codereview.chromium.org/5537001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5914 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Approximation is done by building a dominators tree for the heap graph.
Dominator nodes and retained sizes are serialized into JSON.

Removed:
 - reachable size (it is useless, after all);
 - HeapEntryCalculatedData (size is now stored in the node, retaining
   paths in a hash map);

Review URL: http://codereview.chromium.org/5154007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5867 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=sgjesse@chromium.org

Review URL: http://codereview.chromium.org/5198003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5851 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Otherwise, retaned memory sizes are not precise. This increases size
of heap snapshot, I will deal with this later. Heap objects and
references previously missing in snapshot are now marked as 'hidden'.
That means, they not shown to user, but participate in sizes
calculation.

Other small changes:
 - added 'shortcut' graph edges: e.g. to pin global objects on top
   level;
 - meta-information in JSON snapshot is no more double encoded.

Review URL: http://codereview.chromium.org/5139002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5849 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

HeapNumbers do consume memory, so it's worth dumping them. However, we
don't dump their values, as they are not as self-descriptive as values
of strings, and they will increase snapshot size. Storing heap numbers
values can be added if we will feel a sufficient demand for that.

InternalFields are used, e.g. for storing references to DOM nodes
event handlers.

Review URL: http://codereview.chromium.org/3769007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5635 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

I created a heap snapshot in Chromium, and then started comparing
it side-by-side with representations of objects provided by
the debugger, fixing discrepancies.

Review URL: http://codereview.chromium.org/3590029

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5612 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

to avoid storing serialized snapshot on VM, instead it is emitted
using output stream interface.

The size of JSON emitted is roughly equal to used heap size
(when stored as an ASCII string).

Now a whole heap snapshot can be serialized and transmitted outside
VM. This makes possible:
  - implementing non-async UI for heap snapshots inspection;
  - storing heap snapshots for further inspection;
  - remote profiling (we can even implement a snapshotting mode
    where a snapshot isn't even stored in VM, only transmitted --
    good for mobile devices);
  - creating tools for outside heap snapshots processing, e.g.
    converting to HPROF.

Review URL: http://codereview.chromium.org/3311028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5450 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This is intended for smoother migration to the new API in Chromium.
Also, aggregated heap snapshots can be used for cheaply obtaining
heap statistics, e.g. in tests.

Review URL: http://codereview.chromium.org/3124024

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5297 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The size of a snapshot is now 65-80% of the JS heap size (tested on
GMail and Wave), previously it was >200%.

BUG=783

Review URL: http://codereview.chromium.org/3060008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5211 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

To trace objects between snapshots, an external map of object tags is
maintained. After the first heap snapshot has been taken, the map is
updated by reporting object moves from the GC. If no snapshots were
taken, there is no overhead (except for flag checking).

I considered graph comparison algorithms that doesn't require using
object tags, but they are all of a high computational complexity, and
will still fail to detect object moves properly, even for trivial
cases, so using tags looks like unavoidable.

Review URL: http://codereview.chromium.org/3020002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5078 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/2846012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4891 ce2b1a6d-e550-0410-aec6-3dcde31c8c00