tree c6aa955dbe5bdd942d9526894b15f549203e26d3
parent 381392b397ba2b8c569e954eac612b72e81afac9
author Lorenzo Colitti <lorenzo@google.com> 1583144655 +0900
committer Lorenzo Colitti <lorenzo@google.com> 1584081055 +0900

Make NetworkFactory a single-use object.

Currently, when bluetooth tethering is disabled, the bluetooth
process crashes because unregister() calls setScoreFilter() and
immediately nulls out mProvider. This crashes as soon as the
message posted by setScoreFilter() dereferences mProvider from
the handler thread.

This sort of teardown problem is very difficult to fix given
NetworkFactory's threading model where some code runs on the
handler thread and some code runs on whatever thread calls it.
Instead of complicating the code to do this, simply make it
impossible to call register() after having called unregister().
The only factory that does so today is bluetooth tethering, and
that can be trivially modified to create and register a new
factory instead.

This CL renames the unregister() method to terminate() in order
to make it clear that the object cannot be reused, and also to
ensure that no other code in the tree is unexpectedly calling
unregister().

Bug: 148635501
Test: atest FrameworksNetTests
Change-Id: Icf4c7a957e46e4ba017c0a5984e5c42a75b36ecd