PendingIntent.send will throw CanceledException when the intent
can't be sent, because it was canceled or some other reason. In
some, but not all of these cases, it will still call onSendFinished
after the send is done. This means there is no way to be sure
to do something exactly once after the intent is sent.
Unfortunately, ConnectivityService must keep a wakelock until
sent is finished, and wakelocks must be released exactly once.
Too bad.
The simplest solution is to create a specialized listener object
that can manage the lifecycle of the wakelock. This allows
very localized code, easy review and checking, cheap thread
safety, and not creating multiple locks. It also avoids the
ConnectivityService class implementing OnFinished itself,
which is arguably not very readable considering how big
the class is.
Test: new test that crashes the system without the patch
Fixes: 390043283
Change-Id: Ice528eddaedb4d663098eb2bb0ae7183dafbc073
f34735ebdc