RTCStatsCollector: Utilize network thread to minimize thread hops.

RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetStats[_s] which can be invoked on
the signaling thread or on any thread if a ChannelNamePairs argument is
present (provided by WebRtcSession::GetChannelNamePairs on the signaling
thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
Review-Url: https://codereview.webrtc.org/2583883002
Cr-Commit-Position: refs/heads/master@{#15672}
Committed: https://chromium.googlesource.com/external/webrtc/+/df6075a77ffae5e0de7c272abc56183faf04814e

[hbos, 2016-12-16 13:54:02]

The CQ bit was checked by hbos@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-16 13:54:06]

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

[hbos, 2016-12-16 13:55:27]

Description was changed from

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetSessionStats which can be invoked
on the signaling thread or on any thread if a ChannelNamePairs argument
is present (provided by WebRtcSession::GetChannelNamePairs on the
signaling thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
==========

to

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetSessionStats which can be invoked
on the signaling thread or on any thread if a ChannelNamePairs argument
is present (provided by WebRtcSession::GetChannelNamePairs on the
signaling thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
==========

[hbos, 2016-12-16 13:57:16]

hbos@webrtc.org changed reviewers:
+ deadbeef@webrtc.org, hta@webrtc.org, pthatcher@webrtc.org

[hbos, 2016-12-16 13:57:16]

PTAL pthatcher, deadbeef, hta.

This is a re-upload of https://codereview.webrtc.org/2567243003/, the CQ stopped
working for some reason...

[commit-bot: I haz the power, 2016-12-16 14:24:20]

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

[commit-bot: I haz the power, 2016-12-16 14:24:21]

Dry run: This issue passed the CQ dry run.

[Taylor Brandstetter, 2016-12-16 18:31:55]

If this is just a reupload, lgtm

[hta-webrtc, 2016-12-19 09:32:58]

lgtm

feel free to address or disregard comments.

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.cc
File webrtc/api/webrtcsession.cc (right):

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.cc#n...
webrtc/api/webrtcsession.cc:998: rtc::Bind(&WebRtcSession::GetSessionStats_n,
this, channel_name_pairs));
Blocking call? TODO(make async)?

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.h
File webrtc/api/webrtcsession.h (right):

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.h#ne...
webrtc/api/webrtcsession.h:283: // network thread a thread hop will happen.
Does this mean that the parameterless version should be named GetStats_s?

Function overloading is something we should do when it's important; it's got so
much potential for confusion, it's nice when we don't have to use it.

[hbos, 2016-12-19 09:51:46]

The CQ bit was checked by hbos@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-19 09:51:49]

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

[commit-bot: I haz the power, 2016-12-19 10:07:46]

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

[commit-bot: I haz the power, 2016-12-19 10:07:47]

Dry run: This issue passed the CQ dry run.

[hbos, 2016-12-19 12:36:40]

Patchset #2 (id:20001) has been deleted

[hbos, 2016-12-19 12:37:28]

The CQ bit was checked by hbos@webrtc.org

[hbos, 2016-12-19 12:37:28]

The patchset sent to the CQ was uploaded after l-g-t-m from hta@webrtc.org,
deadbeef@webrtc.org
Link to the patchset: https://codereview.webrtc.org/2583883002/#ps40001 (title:
"Addressed comments")

[commit-bot: I haz the power, 2016-12-19 12:37:36]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[hbos, 2016-12-19 12:37:40]

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.cc
File webrtc/api/webrtcsession.cc (right):

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.cc#n...
webrtc/api/webrtcsession.cc:998: rtc::Bind(&WebRtcSession::GetSessionStats_n,
this, channel_name_pairs));
On 2016/12/19 09:32:57, hta-webrtc wrote:
> Blocking call? TODO(make async)?

If you want non-blocking you can invoke is asynchronously on the network-thread
yourself. My usage case does not involve callbacks.

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.h
File webrtc/api/webrtcsession.h (right):

https://codereview.webrtc.org/2583883002/diff/1/webrtc/api/webrtcsession.h#ne...
webrtc/api/webrtcsession.h:283: // network thread a thread hop will happen.
On 2016/12/19 09:32:58, hta-webrtc wrote:
> Does this mean that the parameterless version should be named GetStats_s?
> 
> Function overloading is something we should do when it's important; it's got
so
> much potential for confusion, it's nice when we don't have to use it.

Done.

[hbos, 2016-12-19 12:39:02]

Description was changed from

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetSessionStats which can be invoked
on the signaling thread or on any thread if a ChannelNamePairs argument
is present (provided by WebRtcSession::GetChannelNamePairs on the
signaling thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
==========

to

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetStats[_s] which can be invoked on
the signaling thread or on any thread if a ChannelNamePairs argument is
present (provided by WebRtcSession::GetChannelNamePairs on the signaling
thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
==========

[hbos, 2016-12-19 12:48:32]

Patchset #3 (id:60001) has been deleted

[hbos, 2016-12-19 12:48:57]

The CQ bit was checked by hbos@webrtc.org

[hbos, 2016-12-19 12:48:57]

The patchset sent to the CQ was uploaded after l-g-t-m from hta@webrtc.org,
deadbeef@webrtc.org
Link to the patchset: https://codereview.webrtc.org/2583883002/#ps40001 (title:
"Addressed comments")

[commit-bot: I haz the power, 2016-12-19 12:49:06]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-12-19 12:58:02]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1482151737232330,
"parent_rev": "20d05a9f71a9c63d8b0d538b983bfa053db76613", "commit_rev":
"df6075a77ffae5e0de7c272abc56183faf04814e"}

[commit-bot: I haz the power, 2016-12-19 12:58:04]

Description was changed from

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetStats[_s] which can be invoked on
the signaling thread or on any thread if a ChannelNamePairs argument is
present (provided by WebRtcSession::GetChannelNamePairs on the signaling
thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816
==========

to

==========
RTCStatsCollector: Utilize network thread to minimize thread hops.

(This is a re-upload of https://codereview.webrtc.org/2567243003/, the
CQ stopped working there.)

The previously used WebRtcSession::GetTransportStats did a synchronous
invoke per channel (voice, video, data) on the signaling thread to the
network thread - e.g. 3 blocking invokes.

It is replaced by WebRtcSession::GetStats[_s] which can be invoked on
the signaling thread or on any thread if a ChannelNamePairs argument is
present (provided by WebRtcSession::GetChannelNamePairs on the signaling
thread).

With these changes, and changes allowing the getting of certificates
from any thread, the RTCStatsCollector can turn the 3 blocking thread
invokes into 1 non-blocking invoke.

BUG=webrtc:6875, chromium:627816

Review-Url: https://codereview.webrtc.org/2583883002
Cr-Commit-Position: refs/heads/master@{#15672}
Committed:
https://chromium.googlesource.com/external/webrtc/+/df6075a77ffae5e0de7c272ab...
==========

[commit-bot: I haz the power, 2016-12-19 12:58:06]

Committed patchset #2 (id:40001) as
https://chromium.googlesource.com/external/webrtc/+/df6075a77ffae5e0de7c272ab...