memory-infra: Fix deadlock in MemoryDumpManager

memory-infra: Fix deadlock in MemoryDumpManager

When we destroy a memory dump manager (MDM is a singleton so this only
happens in tests) we attempt to stop the thread under the lock. This
can lead to a deadlock if there are outstanding tasks which also try to
take the lock. Instead we should get a pointer to the thread under the
lock, stop the thread, then finally reset the pointer which is what this
CL does.

BUG=721072
Review-Url: https://codereview.chromium.org/2881563002
Cr-Commit-Position: refs/heads/master@{#470989}
Committed: https://chromium.googlesource.com/chromium/src/+/f1610b19b843e8cdc00a215074f9c9e04de9dd17

[hjd, 2017-05-11 13:49:07]

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

[hjd, 2017-05-11 13:49:24]

hjd@chromium.org changed reviewers:
+ primiano@chromium.org

[hjd, 2017-05-11 13:49:24]

ptal, thanks! :)

[commit-bot: I haz the power, 2017-05-11 13:49:47]

Dry run: CQ is trying da patch.

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

[Primiano Tucci (use gerrit), 2017-05-11 13:53:27]

LGTM with 1 comment

https://codereview.chromium.org/2881563002/diff/1/base/trace_event/memory_dum...
File base/trace_event/memory_dump_manager.cc (right):

https://codereview.chromium.org/2881563002/diff/1/base/trace_event/memory_dum...
base/trace_event/memory_dump_manager.cc:186: {
no need for these extra set of braces here

[hjd, 2017-05-11 14:18:41]

https://codereview.chromium.org/2881563002/diff/1/base/trace_event/memory_dum...
File base/trace_event/memory_dump_manager.cc (right):

https://codereview.chromium.org/2881563002/diff/1/base/trace_event/memory_dum...
base/trace_event/memory_dump_manager.cc:186: {
On 2017/05/11 13:53:27, Primiano Tucci wrote:
> no need for these extra set of braces here

Done.

[hjd, 2017-05-11 15:16:05]

The CQ bit was checked by hjd@chromium.org

[hjd, 2017-05-11 15:16:05]

The patchset sent to the CQ was uploaded after l-g-t-m from
primiano@chromium.org
Link to the patchset: https://codereview.chromium.org/2881563002/#ps20001
(title: "remove brackets")

[commit-bot: I haz the power, 2017-05-11 15:16:31]

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, 2017-05-11 16:27:46]

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

[commit-bot: I haz the power, 2017-05-11 16:27:47]

Try jobs failed on following builders:
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)

[hjd, 2017-05-11 16:32:56]

The CQ bit was checked by hjd@chromium.org

[commit-bot: I haz the power, 2017-05-11 16:34:02]

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, 2017-05-11 17:16:21]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1494520376614440,
"parent_rev": "ad1eaa6c4fd1c53f6e4be4da087a8c13a1e84058", "commit_rev":
"f1610b19b843e8cdc00a215074f9c9e04de9dd17"}

[commit-bot: I haz the power, 2017-05-11 17:16:32]

Description was changed from

==========
memory-infra: Fix deadlock in MemoryDumpManager

When we destroy a memory dump manager (MDM is a singleton so this only
happens in tests) we attempt to stop the thread under the lock. This
can lead to a deadlock if there are outstanding tasks which also try to
take the lock. Instead we should get a pointer to the thread under the
lock, stop the thread, then finally reset the pointer which is what this
CL does.

BUG=721072
==========

to

==========
memory-infra: Fix deadlock in MemoryDumpManager

When we destroy a memory dump manager (MDM is a singleton so this only
happens in tests) we attempt to stop the thread under the lock. This
can lead to a deadlock if there are outstanding tasks which also try to
take the lock. Instead we should get a pointer to the thread under the
lock, stop the thread, then finally reset the pointer which is what this
CL does.

BUG=721072

Review-Url: https://codereview.chromium.org/2881563002
Cr-Commit-Position: refs/heads/master@{#470989}
Committed:
https://chromium.googlesource.com/chromium/src/+/f1610b19b843e8cdc00a215074f9...
==========

[commit-bot: I haz the power, 2017-05-11 17:16:34]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/f1610b19b843e8cdc00a215074f9...