Merge "Add a lock to protect persistent stats snapshot" into qt-dev

services/core/java/com/android/server/net/NetworkStatsFactory.java

@@ -28,6 +28,7 @@ import android.net.NetworkStats;
 import android.os.StrictMode;
 import android.os.SystemClock;
 
+import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.ProcFileReader;
@@ -65,6 +66,7 @@ public class NetworkStatsFactory {
     private boolean mUseBpfStats;
 
     // A persistent Snapshot since device start for eBPF stats
+    @GuardedBy("mPersistSnapshot")
     private final NetworkStats mPersistSnapshot;
 
     // TODO: only do adjustments in NetworkStatsService and remove this.
@@ -284,6 +286,7 @@ public class NetworkStatsFactory {
                 stats = new NetworkStats(SystemClock.elapsedRealtime(), -1);
             }
             if (mUseBpfStats) {
+                synchronized (mPersistSnapshot) {
                     if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), UID_ALL,
                             null, TAG_ALL, mUseBpfStats) != 0) {
                         throw new IOException("Failed to parse network stats");
@@ -293,6 +296,7 @@ public class NetworkStatsFactory {
                     NetworkStats result = mPersistSnapshot.clone();
                     result.filter(limitUid, limitIfaces, limitTag);
                     return result;
+                }
             } else {
                 if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), limitUid,
                         limitIfaces, limitTag, mUseBpfStats) != 0) {