From 1794157872ee95ef865c31d312621132359f9b5c Mon Sep 17 00:00:00 2001
From: junyulai <junyulai@google.com>
Date: Wed, 27 May 2020 14:44:13 +0800
Subject: [PATCH] Fix perfd receives delayed {wifi|mobile}_bytes_transfer atoms

Test: manual
Bug: 156313635
Change-Id: Ie393451e9a3c962fe086f5df283ed0075cce1db4
---
 .../stats/pull/StatsPullAtomService.java      | 49 ++++++++-----------
 1 file changed, 21 insertions(+), 28 deletions(-)

diff --git a/services/core/java/com/android/server/stats/pull/StatsPullAtomService.java b/services/core/java/com/android/server/stats/pull/StatsPullAtomService.java
index 24378a5b6fbda..263c096f056f3 100644
--- a/services/core/java/com/android/server/stats/pull/StatsPullAtomService.java
+++ b/services/core/java/com/android/server/stats/pull/StatsPullAtomService.java
@@ -19,6 +19,8 @@ package com.android.server.stats.pull;
 import static android.app.AppOpsManager.OP_FLAG_SELF;
 import static android.app.AppOpsManager.OP_FLAG_TRUSTED_PROXIED;
 import static android.app.usage.NetworkStatsManager.FLAG_AUGMENT_WITH_SUBSCRIPTION_PLAN;
+import static android.app.usage.NetworkStatsManager.FLAG_POLL_FORCE;
+import static android.app.usage.NetworkStatsManager.FLAG_POLL_ON_OPEN;
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PermissionInfo.PROTECTION_DANGEROUS;
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
@@ -236,11 +238,6 @@ public class StatsPullAtomService extends SystemService {
     private static final String DANGEROUS_PERMISSION_STATE_SAMPLE_RATE =
             "dangerous_permission_state_sample_rate";
 
-    private final Object mNetworkStatsLock = new Object();
-    @GuardedBy("mNetworkStatsLock")
-    @Nullable
-    private INetworkStatsSession mNetworkStatsSession;
-
     private final Object mThermalLock = new Object();
     @GuardedBy("mThermalLock")
     private IThermalService mThermalService;
@@ -690,29 +687,19 @@ public class StatsPullAtomService extends SystemService {
      * null if the service or binder cannot be obtained.
      */
     @Nullable
-    private INetworkStatsSession getNetworkStatsSession() {
-        synchronized (mNetworkStatsLock) {
-            if (mNetworkStatsSession != null) return mNetworkStatsSession;
+    private INetworkStatsSession getNetworkStatsSession(boolean forcePoll) {
+        final INetworkStatsService networkStatsService =
+                INetworkStatsService.Stub.asInterface(
+                        ServiceManager.getService(Context.NETWORK_STATS_SERVICE));
+        if (networkStatsService == null) return null;
 
-            final INetworkStatsService networkStatsService =
-                    INetworkStatsService.Stub.asInterface(
-                            ServiceManager.getService(Context.NETWORK_STATS_SERVICE));
-            if (networkStatsService == null) return null;
-
-            try {
-                networkStatsService.asBinder().linkToDeath(() -> {
-                    synchronized (mNetworkStatsLock) {
-                        mNetworkStatsSession = null;
-                    }
-                }, /* flags */ 0);
-                mNetworkStatsSession = networkStatsService.openSessionForUsageStats(
-                        FLAG_AUGMENT_WITH_SUBSCRIPTION_PLAN, mContext.getOpPackageName());
-            } catch (RemoteException e) {
-                Slog.e(TAG, "Cannot get NetworkStats session", e);
-                mNetworkStatsSession = null;
-            }
-
-            return mNetworkStatsSession;
+        try {
+            return networkStatsService.openSessionForUsageStats(
+                    FLAG_AUGMENT_WITH_SUBSCRIPTION_PLAN | (forcePoll ? FLAG_POLL_FORCE
+                            : FLAG_POLL_ON_OPEN), mContext.getOpPackageName());
+        } catch (RemoteException e) {
+            Slog.e(TAG, "Cannot get NetworkStats session", e);
+            return null;
         }
     }
 
@@ -1023,7 +1010,13 @@ public class StatsPullAtomService extends SystemService {
         final long bucketDuration = Settings.Global.getLong(mContext.getContentResolver(),
                 NETSTATS_UID_BUCKET_DURATION, NETSTATS_UID_DEFAULT_BUCKET_DURATION_MS);
         try {
-            final NetworkStats stats = getNetworkStatsSession().getSummaryForAllUid(template,
+            // TODO (b/156313635): This is short-term hack to allow perfd gets updated networkStats
+            //  history when query in every second in order to show realtime statistics. However,
+            //  this is not a good long-term solution since NetworkStatsService will make frequent
+            //  I/O and also block main thread when polling.
+            //  Consider making perfd queries NetworkStatsService directly.
+            final NetworkStats stats = getNetworkStatsSession(template.getMatchRule()
+                    == NetworkTemplate.MATCH_WIFI_WILDCARD).getSummaryForAllUid(template,
                     currentTimeInMillis - elapsedMillisSinceBoot - bucketDuration,
                     currentTimeInMillis, includeTags);
             return stats;