Ensure counters are initialized, to avoid init on non-joinable threads.

Ensure counters are initialized, to avoid init on non-joinable threads.

This occurs in the wasm scenario described in the referenced bug.
DecodeWasmModule collects statistics. Blink inserts a CreateHistogramCallback that
can't instantiate a histogram on non-joinable threads. Turns out, DecodeWasmModule
is scheduled on such a thread, now that we have async compilation.

This fix pre-initializes histograms when the callback is applied, which is assumed to
be in a context that can carry out the instantiation. In Blink, this happens on the main
thread.

BUG=chromium:709684
Review-Url: https://codereview.chromium.org/2812543002
Cr-Commit-Position: refs/heads/master@{#44522}
Committed: https://chromium.googlesource.com/v8/v8/+/022e7ddf232b0696eb595769fa702463c417db5e

[Mircea Trofin, 2017-04-10 06:31:56]

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

[commit-bot: I haz the power, 2017-04-10 06:32:00]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Mircea Trofin, 2017-04-10 06:44:32]

Description was changed from

==========
Ensure counters are initialized, to avoid init on non-joinable threads.

BUG=
==========

to

==========
Ensure counters are initialized, to avoid init on non-joinable threads.

This occurs in the wasm scenario described in the referenced bug.
DecodeWasmModule collects statistics. Blink inserts a CreateHistogramCallback
that
can't instantiate a histogram on non-joinable threads. Turns out,
DecodeWasmModule
is scheduled on such a thread, now that we have async compilation.

This fix pre-initializes histograms when the callback is applied, which is
assumed to
be in a context that can carry out the instantiation. In Blink, this happens on
the main
thread.

BUG=chromium:709684
==========

[Mircea Trofin, 2017-04-10 06:44:32]

mtrofin@chromium.org changed reviewers:
+ jochen@chromium.org

[Mircea Trofin, 2017-04-10 06:50:41]

Hello Jochen,

could you please take a look at this CL. I don't have background in the 
counters design, so this may be an approximate fix for the referenced
bug (case in which we should identify the more appropriate CL, of
course).

If this looks right:
- I suppose we'd need the same mechanics for stats - currently, 
SetCounterFunction doesn't appear to be set from Blink, though.
- Any ideas how to test this from v8? The issue is un-reproable 
currently on the v8 side, because we don't have mechanisms for 
creating histograms/counters, it appears.

[commit-bot: I haz the power, 2017-04-10 07:08:58]

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

[commit-bot: I haz the power, 2017-04-10 07:08:59]

Dry run: This issue passed the CQ dry run.

[jochen (gone - plz use gerrit), 2017-04-10 12:42:47]

lgtm

[Mircea Trofin, 2017-04-10 13:09:05]

The CQ bit was checked by mtrofin@chromium.org

[commit-bot: I haz the power, 2017-04-10 13:09:08]

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, 2017-04-10 13:11:03]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1491829745808880, "parent_rev":
"88e169dc62103ef4eb1cc4a685d7471d921db044", "commit_rev":
"022e7ddf232b0696eb595769fa702463c417db5e"}

[commit-bot: I haz the power, 2017-04-10 13:11:12]

Description was changed from

==========
Ensure counters are initialized, to avoid init on non-joinable threads.

This occurs in the wasm scenario described in the referenced bug.
DecodeWasmModule collects statistics. Blink inserts a CreateHistogramCallback
that
can't instantiate a histogram on non-joinable threads. Turns out,
DecodeWasmModule
is scheduled on such a thread, now that we have async compilation.

This fix pre-initializes histograms when the callback is applied, which is
assumed to
be in a context that can carry out the instantiation. In Blink, this happens on
the main
thread.

BUG=chromium:709684
==========

to

==========
Ensure counters are initialized, to avoid init on non-joinable threads.

This occurs in the wasm scenario described in the referenced bug.
DecodeWasmModule collects statistics. Blink inserts a CreateHistogramCallback
that
can't instantiate a histogram on non-joinable threads. Turns out,
DecodeWasmModule
is scheduled on such a thread, now that we have async compilation.

This fix pre-initializes histograms when the callback is applied, which is
assumed to
be in a context that can carry out the instantiation. In Blink, this happens on
the main
thread.

BUG=chromium:709684

Review-Url: https://codereview.chromium.org/2812543002
Cr-Commit-Position: refs/heads/master@{#44522}
Committed:
https://chromium.googlesource.com/v8/v8/+/022e7ddf232b0696eb595769fa702463c41...
==========

[commit-bot: I haz the power, 2017-04-10 13:11:13]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/022e7ddf232b0696eb595769fa702463c41...

[jgruber, 2017-04-10 14:56:36]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2812653002/ by jgruber@chromium.org.

The reason for reverting is:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20gyp/builds....