leveldb_service: Attempt to fix deadlock on shutdown.

leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
Committed: https://crrev.com/16167c22ec91beec0b7cbe26d15049bbda589db3
Cr-Commit-Position: refs/heads/master@{#383112}

[Elliot Glaysher, 2016-03-23 21:46:33]

erg@chromium.org changed reviewers:
+ sky@chromium.org

[Elliot Glaysher, 2016-03-23 21:46:34]

The problem with nondeterministic deadlocks is that you're never sure you
actually fixed them. Previously, I could trigger the deadlock about one in
twenty times. I've run this code two hundred times now and haven't seen it lock
up, which may just mean I've changed timings ever so slightly instead of
actually fixing the problem. :-/

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
File components/leveldb/leveldb_database_impl.cc (right):

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
components/leveldb/leveldb_database_impl.cc:115: return;
This was just wrong on my part.

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
File components/leveldb/leveldb_service_unittest.cc (left):

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
components/leveldb/leveldb_service_unittest.cc:283: TEST_F(LevelDBApptest,
InvalidArgumentOnInvalidSnapshot) {
Oddly enough, this test was never actually disabled; it just had some #defines
added in front of it which were never referred to.

[Elliot Glaysher, 2016-03-23 21:54:56]

erg@chromium.org changed reviewers:
+ jam@chromium.org
- sky@chromium.org

[Elliot Glaysher, 2016-03-23 21:54:57]

-sky, +jam

[Elliot Glaysher, 2016-03-24 17:20:23]

Description was changed from

==========
leveldb_service: Attempt to fix deadlock on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
==========

to

==========
leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
==========

[jam, 2016-03-24 17:27:39]

lgtm

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
File components/leveldb/leveldb_file_thread.cc (right):

https://codereview.chromium.org/1825413003/diff/20001/components/leveldb/leve...
components/leveldb/leveldb_file_thread.cc:651: // event. (This dependency will
get cleared in OnLockFileCompelte if we
nit: OnLockFileComplete

[Elliot Glaysher, 2016-03-24 17:55:00]

The CQ bit was checked by erg@chromium.org

[Elliot Glaysher, 2016-03-24 17:55:00]

The patchset sent to the CQ was uploaded after l-g-t-m from jam@chromium.org
Link to the patchset: https://codereview.chromium.org/1825413003/#ps40001
(title: "typo")

[commit-bot: I haz the power, 2016-03-24 17:55:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1825413003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1825413003/40001

[commit-bot: I haz the power, 2016-03-24 19:04:25]

Description was changed from

==========
leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
==========

to

==========
leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
==========

[commit-bot: I haz the power, 2016-03-24 19:04:26]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-03-24 19:05:46]

Description was changed from

==========
leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977
==========

to

==========
leveldb_service: Attempt to fix hang on shutdown.

On mojo connection errors, we should call WaitableEvent::Signal() on any
events that are blocking the various leveldb threads.

BUG=594977

Committed: https://crrev.com/16167c22ec91beec0b7cbe26d15049bbda589db3
Cr-Commit-Position: refs/heads/master@{#383112}
==========

[commit-bot: I haz the power, 2016-03-24 19:05:48]

Patchset 3 (id:??) landed as
https://crrev.com/16167c22ec91beec0b7cbe26d15049bbda589db3
Cr-Commit-Position: refs/heads/master@{#383112}