Fix crash in anomaly job service

If job has been stopped by any reason, we should cancel the background
thread, otherwise it will throw SecurityException when dequeuing from
JobParams.

This CL adds a lock to synchronize the method and stops dequeue work
if job has been canceled.

Change-Id: I7732b7f7d444a55a4b4ba6645cd2c16b6f840a6c
Merged-In: I7732b7f7d444a55a4b4ba6645cd2c16b6f840a6c
Fixes: 77968649
Test: RunSettingsRoboTests

src/com/android/settings/fuelgauge/batterytip/AnomalyDetectionJobService.java

@@ -38,6 +38,7 @@ import android.os.StatsDimensionsValue;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
+import android.support.annotation.GuardedBy;
 import android.support.annotation.VisibleForTesting;
 import android.util.Log;
 import android.util.Pair;
@@ -65,10 +66,13 @@ public class AnomalyDetectionJobService extends JobService {
     static final int UID_NULL = -1;
     @VisibleForTesting
     static final int STATSD_UID_FILED = 1;
-
     @VisibleForTesting
     static final long MAX_DELAY_MS = TimeUnit.MINUTES.toMillis(30);
 
+    private final Object mLock = new Object();
+    @GuardedBy("mLock")
+    private boolean mIsJobCanceled = false;
+
     public static void scheduleAnomalyDetection(Context context, Intent intent) {
         final JobScheduler jobScheduler = context.getSystemService(JobScheduler.class);
         final ComponentName component = new ComponentName(context,
@@ -102,14 +106,14 @@ public class AnomalyDetectionJobService extends JobService {
                     .getFactory(this).getMetricsFeatureProvider();
             batteryUtils.initBatteryStatsHelper(batteryStatsHelper, null /* bundle */, userManager);
 
-            for (JobWorkItem item = params.dequeueWork(); item != null;
-                    item = params.dequeueWork()) {
+            for (JobWorkItem item = dequeueWork(params); item != null; item = dequeueWork(params)) {
                 saveAnomalyToDatabase(context, batteryStatsHelper, userManager,
                         batteryDatabaseManager, batteryUtils, policy, powerWhitelistBackend,
                         contentResolver, powerUsageFeatureProvider, metricsFeatureProvider,
                         item.getIntent().getExtras());
+
+                completeWork(params, item);
             }
-            jobFinished(params, false /* wantsReschedule */);
         });
 
         return true;
@@ -117,7 +121,10 @@ public class AnomalyDetectionJobService extends JobService {
 
     @Override
     public boolean onStopJob(JobParameters jobParameters) {
-        return false;
+        synchronized (mLock) {
+            mIsJobCanceled = true;
+        }
+        return true; // Need to reschedule
     }
 
     @VisibleForTesting
@@ -229,4 +236,26 @@ public class AnomalyDetectionJobService extends JobService {
         return anomalyInfo.anomalyType
                 == StatsManagerConfig.AnomalyType.EXCESSIVE_BACKGROUND_SERVICE;
     }
+
+    @VisibleForTesting
+    JobWorkItem dequeueWork(JobParameters parameters) {
+        synchronized (mLock) {
+            if (mIsJobCanceled) {
+                return null;
+            }
+
+            return parameters.dequeueWork();
+        }
+    }
+
+    @VisibleForTesting
+    void completeWork(JobParameters parameters, JobWorkItem item) {
+        synchronized (mLock) {
+            if (mIsJobCanceled) {
+                return;
+            }
+
+            parameters.completeWork(item);
+        }
+    }
 }