tree 0813c91a252ded33abe34e8e626aa0261024e4e7
parent bcc449eeca64fce5302a32fc1cbe757eb5512b2d
author Philip P. Moltmann <moltmann@google.com> 1481675001 -0800
committer Svetoslav Ganov <svetoslavganov@google.com> 1484268179 -0800

Only persist last Shared Preferences state

If multiple async shared preferences writes are queued, all but the
last one can be ignored as they will be overwritten by the last one
anyway.

For commit() we need to make sure that we have at least persisted the
state of the commit.

Generation counts are 64 bit, hence they never overflow.

Test: Produced a lot of SharedPreferences.Editor.apply and did not see
excessive writes anymore, ran SharedPreferences CTS tests
Bug: 33385963
Change-Id: I3968ed4b71befee6eeb90bea1666a0bb646544f6
(cherry picked from commit 31d6889f4c89dd8498e2095f9d8a3c39fbd17c86)