Non-functional optimization to Android NetworkChangeNotifier startup

Non-functional optimization to Android NetworkChangeNotifier startup

Ignore the initial onReceive() callback when registering a
BroadcastRecevier for a sticky Intent as it doesn't offer any
new information.

BUG=647691
R=xunjieli

Committed: https://crrev.com/c9d22a638fceab53238e8ac65dad0f732376ae3a
Cr-Commit-Position: refs/heads/master@{#422162}

[pauljensen, 2016-09-22 15:21:23]

Helen, PTAL, thank you!  This is the fourth in the breakup of the bigger NCN
speed-up CL.

[xunjieli, 2016-09-22 21:22:21]

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
File net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
(right):

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java:622:
mRegistrationPolicy.init(this);
Alternatively we can make init() return a boolean specifying whether subclass
has registered. If so, we do not initialize |mConnectionType|, |mWifiSSID| ,etc.
since those will be handled in register().

I feel that way we have less magic and one fewer state.  WDYT?

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java:666:
mIgnoreNextBroadcast = mContext.registerReceiver(this, mIntentFilter) != null;
What does mContext.registerReceiver() return? What's the significance of that?
Could you add a comment here?

[pauljensen, 2016-09-23 13:55:33]

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
File net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
(right):

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java:622:
mRegistrationPolicy.init(this);
On 2016/09/22 21:22:21, xunjieli wrote:
> Alternatively we can make init() return a boolean specifying whether subclass
> has registered. If so, we do not initialize |mConnectionType|, |mWifiSSID|
,etc.
> since those will be handled in register().
> 
> I feel that way we have less magic and one fewer state.  WDYT?

In addition to the return value of init(), we'd also need a new variable set
during initialization to avoid sending a change signal during the possible
initial registration, so I think this may end up not being any simpler.  This
could also break things because there will be a period between when
NetworkChangeNotifierAutoDetect is constructed and when the message-loop is next
run and the initial onReceive is processed, and during this period the NCN will
not know what the state of the device is.

https://codereview.chromium.org/2366503003/diff/1/net/android/java/src/org/ch...
net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java:666:
mIgnoreNextBroadcast = mContext.registerReceiver(this, mIntentFilter) != null;
On 2016/09/22 21:22:21, xunjieli wrote:
> What does mContext.registerReceiver() return?
https://developer.android.com/reference/android/content/Context.html#register...

> What's the significance of that?

CONNECTIVITY_ACTION is a sticky broadcast, so if registerReceiver() returns a
non-null value we know we will receive an onReceive callback immediately, but it
doesn't indicate an actual change, it's just the last sticky broadcast sent out.

> Could you add a comment here?

Done.

[xunjieli, 2016-09-29 19:58:11]

lgtm. Thanks for the clear documentation!

[pauljensen, 2016-09-30 17:31:39]

The CQ bit was checked by pauljensen@chromium.org

[commit-bot: I haz the power, 2016-09-30 17:32:59]

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, 2016-09-30 18:37:34]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-30 18:42:14]

Description was changed from

==========
Non-functional optimization to Android NetworkChangeNotifier startup

Ignore the initial onReceive() callback when registering a
BroadcastRecevier for a sticky Intent as it doesn't offer any
new information.

BUG=647691
R=xunjieli
==========

to

==========
Non-functional optimization to Android NetworkChangeNotifier startup

Ignore the initial onReceive() callback when registering a
BroadcastRecevier for a sticky Intent as it doesn't offer any
new information.

BUG=647691
R=xunjieli

Committed: https://crrev.com/c9d22a638fceab53238e8ac65dad0f732376ae3a
Cr-Commit-Position: refs/heads/master@{#422162}
==========

[commit-bot: I haz the power, 2016-09-30 18:42:17]

Patchset 2 (id:??) landed as
https://crrev.com/c9d22a638fceab53238e8ac65dad0f732376ae3a
Cr-Commit-Position: refs/heads/master@{#422162}