[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference to hold onto v8::Mo…

[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference to hold onto v8::Module.

Before this CL, ModuleScript referenced v8::Module via SharedPersistent<> in ScriptModule.
This created cycle of v8::Context -> V8PerContextData -> Modulator -> ModuleMap -> ModuleScript -(persistent)-> v8::Module -> v8::Context.

This CL breaks the cycle (partially) by making ModuleScript use TraceWrapperV8Reference to reference v8::Module, and create ScriptModule on the fly.
More CLs will follow to break other parts of the cycle graph.

BUG=594639, 725816
Review-Url: https://codereview.chromium.org/2903813002
Cr-Commit-Position: refs/heads/master@{#474543}
Committed: https://chromium.googlesource.com/chromium/src/+/7fa31ddf3b196d9873d615e7aabe4285fed4cef8

[kouhei (in TOK), 2017-05-24 08:17:34]

The CQ bit was checked by kouhei@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-24 08:18:02]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kouhei (in TOK), 2017-05-24 08:22:28]

Description was changed from

==========
[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference
to hold onto v8::Module.

BUG=594639, 725816
==========

to

==========
[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference
to hold onto v8::Module.

Before this CL, ModuleScript referenced v8::Module via SharedPersistent<> in
ScriptModule.
This created cycle of v8::Context -> V8PerContextData -> Modulator -> ModuleMap
-> ModuleScript -(persistent)-> v8::Module -> v8::Context.

This CL breaks the cycle (partially) by making ModuleScript use
TraceWrapperV8Reference to reference v8::Module, and create ScriptModule on the
fly.
More CLs will follow to break other parts of the cycle graph.

BUG=594639, 725816
==========

[kouhei (in TOK), 2017-05-24 08:22:28]

kouhei@chromium.org changed reviewers:
+ haraken@chromium.org, hiroshige@chromium.org, japhet@chromium.org,
kinuko@chromium.org, mlippautz@chromium.org, module-dev@chromium.org,
yhirano@chromium.org

[kouhei (in TOK), 2017-05-24 08:22:58]

The CQ bit was checked by kouhei@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-24 08:23:26]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[haraken, 2017-05-24 09:28:12]

LGTM

https://codereview.chromium.org/2903813002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/dom/ModuleScript.h (left):

https://codereview.chromium.org/2903813002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/dom/ModuleScript.h:128: ScriptModule record_;

Is there any other place that is holding ScriptModule in an on-heap project? In
general it has a risk of causing leaks like this.

[commit-bot: I haz the power, 2017-05-24 09:38:52]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-24 09:38:53]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[yhirano, 2017-05-24 10:15:28]

lgtm

[Michael Lippautz, 2017-05-24 10:42:21]

LGTM

[kinuko, 2017-05-24 10:45:05]

whoa. lgtm

[kouhei (in TOK), 2017-05-24 13:06:36]

https://codereview.chromium.org/2903813002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/dom/ModuleScript.h (left):

https://codereview.chromium.org/2903813002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/dom/ModuleScript.h:128: ScriptModule record_;
On 2017/05/24 09:28:12, haraken wrote:
> 
> Is there any other place that is holding ScriptModule in an on-heap project?
In
> general it has a risk of causing leaks like this.
> 

Yes. ScriptModuleResolverImpl. There I plan to make the SharedPersistent use
SetPhantom or SetWeak.

[kouhei (in TOK), 2017-05-25 01:44:12]

The CQ bit was checked by kouhei@chromium.org

[kouhei (in TOK), 2017-05-25 01:44:12]

The patchset sent to the CQ was uploaded after l-g-t-m from
mlippautz@chromium.org, kinuko@chromium.org, haraken@chromium.org,
yhirano@chromium.org
Link to the patchset: https://codereview.chromium.org/2903813002/#ps40001
(title: "testfix")

[commit-bot: I haz the power, 2017-05-25 01:45:00]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-25 03:33:23]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1495676652086590,
"parent_rev": "2cab1a07df84484b5088546837ad1c5b1310c00f", "commit_rev":
"7fa31ddf3b196d9873d615e7aabe4285fed4cef8"}

[commit-bot: I haz the power, 2017-05-25 03:33:32]

Description was changed from

==========
[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference
to hold onto v8::Module.

Before this CL, ModuleScript referenced v8::Module via SharedPersistent<> in
ScriptModule.
This created cycle of v8::Context -> V8PerContextData -> Modulator -> ModuleMap
-> ModuleScript -(persistent)-> v8::Module -> v8::Context.

This CL breaks the cycle (partially) by making ModuleScript use
TraceWrapperV8Reference to reference v8::Module, and create ScriptModule on the
fly.
More CLs will follow to break other parts of the cycle graph.

BUG=594639, 725816
==========

to

==========
[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference
to hold onto v8::Module.

Before this CL, ModuleScript referenced v8::Module via SharedPersistent<> in
ScriptModule.
This created cycle of v8::Context -> V8PerContextData -> Modulator -> ModuleMap
-> ModuleScript -(persistent)-> v8::Module -> v8::Context.

This CL breaks the cycle (partially) by making ModuleScript use
TraceWrapperV8Reference to reference v8::Module, and create ScriptModule on the
fly.
More CLs will follow to break other parts of the cycle graph.

BUG=594639, 725816

Review-Url: https://codereview.chromium.org/2903813002
Cr-Commit-Position: refs/heads/master@{#474543}
Committed:
https://chromium.googlesource.com/chromium/src/+/7fa31ddf3b196d9873d615e7aabe...
==========

[commit-bot: I haz the power, 2017-05-25 03:33:36]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/7fa31ddf3b196d9873d615e7aabe...