tree 4d3b089e0b2ed8035ae5b213394703f7ec3a28c4
parent 584ab0d9d98d0f0ae0b5974353e8369f46fff889
author Arthur Ishiguro <arthuri@google.com> 1586188220 -0700
committer Arthur Ishiguro <arthuri@google.com> 1586217505 -0700

Fix deadlock on SensorService

If mLock is held by SensorService::threadLoop(), and a new call
from SensorEventConnection comes in to e.g. enable/disable a sensor,
this thread must wait for the mLock to be released. However, if this
thread holds mConnectionLock in SensorEventConnection, and SensorService
invokes SensorEventConnection.sendEvent, the system will come into a
deadlock because both threads are waiting for each other.

To avoid this situation unlock SensotEventConnection's mConnectionLock
while going out of scope.

Also create separate mutexes for modifying mSensorInfo and
mSensorInfoBackup for better separation.

Bug: 153188258
Test: 1) Run sensor logger and enable sensor, put app in background.
      2) Open a_sns_test and start streaming sensor samples
      3) Open app again and verify no system ANR, sensor samples
      continue to be received on app.
Change-Id: If137f39918a8b1148dcc00f1b1d82b4454bb5c7b