Snap for 6214566 from 8ac64bc013a7b14c9996f504eb4c50b6d71c9257 to rvc-release

Change-Id: I2dc4f607967f2e9f5baaf624e97aba7085b9b972

core/java/android/app/usage/NetworkStatsManager.java

@@ -526,15 +526,17 @@ public class NetworkStatsManager {
     }
 
     /**
-     * Registers a custom provider of {@link android.net.NetworkStats} to combine the network
+     * Registers a custom provider of {@link android.net.NetworkStats} to provide network statistics
-     * statistics that cannot be seen by the kernel to system. To unregister, invoke
+     * to the system. To unregister, invoke {@link NetworkStatsProviderCallback#unregister()}.
-     * {@link NetworkStatsProviderCallback#unregister()}.
+     * Note that no de-duplication of statistics between providers is performed, so each provider
+     * must only report network traffic that is not being reported by any other provider.
      *
-     * @param tag a human readable identifier of the custom network stats provider.
+     * @param tag a human readable identifier of the custom network stats provider. This is only
-     * @param provider a custom implementation of {@link AbstractNetworkStatsProvider} that needs to
+     *            used for debugging.
-     *                 be registered to the system.
+     * @param provider the subclass of {@link AbstractNetworkStatsProvider} that needs to be
+     *                 registered to the system.
      * @return a {@link NetworkStatsProviderCallback}, which can be used to report events to the
-     *         system.
+     *         system or unregister the provider.
      * @hide
      */
     @SystemApi

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

@@ -155,6 +155,8 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Collect and persist detailed network statistics, and provide this data to
@@ -255,7 +257,6 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     }
 
     private final Object mStatsLock = new Object();
-    private final Object mStatsProviderLock = new Object();
 
     /** Set of currently active ifaces. */
     @GuardedBy("mStatsLock")
@@ -280,8 +281,11 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     private final DropBoxNonMonotonicObserver mNonMonotonicObserver =
             new DropBoxNonMonotonicObserver();
 
+    private static final int MAX_STATS_PROVIDER_POLL_WAIT_TIME_MS = 100;
     private final RemoteCallbackList<NetworkStatsProviderCallbackImpl> mStatsProviderCbList =
             new RemoteCallbackList<>();
+    /** Semaphore used to wait for stats provider to respond to request stats update. */
+    private final Semaphore mStatsProviderSem = new Semaphore(0, true);
 
     @GuardedBy("mStatsLock")
     private NetworkStatsRecorder mDevRecorder;
@@ -1337,6 +1341,25 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         final boolean persistUid = (flags & FLAG_PERSIST_UID) != 0;
         final boolean persistForce = (flags & FLAG_PERSIST_FORCE) != 0;
 
+        // Request asynchronous stats update from all providers for next poll. And wait a bit of
+        // time to allow providers report-in given that normally binder call should be fast.
+        // TODO: request with a valid token.
+        Trace.traceBegin(TRACE_TAG_NETWORK, "provider.requestStatsUpdate");
+        final int registeredCallbackCount = mStatsProviderCbList.getRegisteredCallbackCount();
+        mStatsProviderSem.drainPermits();
+        invokeForAllStatsProviderCallbacks((cb) -> cb.mProvider.requestStatsUpdate(0 /* unused */));
+        try {
+            mStatsProviderSem.tryAcquire(registeredCallbackCount,
+                    MAX_STATS_PROVIDER_POLL_WAIT_TIME_MS, TimeUnit.MILLISECONDS);
+        } catch (InterruptedException e) {
+            // Strictly speaking it's possible a provider happened to deliver between the timeout
+            // and the log, and that doesn't matter too much as this is just a debug log.
+            Log.d(TAG, "requestStatsUpdate - providers responded "
+                    + mStatsProviderSem.availablePermits()
+                    + "/" + registeredCallbackCount + " : " + e);
+        }
+        Trace.traceEnd(TRACE_TAG_NETWORK);
+
         // TODO: consider marking "untrusted" times in historical stats
         final long currentTime = mClock.millis();
 
@@ -1374,10 +1397,6 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
             performSampleLocked();
         }
 
-        // request asynchronous stats update from all providers for next poll.
-        // TODO: request with a valid token.
-        invokeForAllStatsProviderCallbacks((cb) -> cb.mProvider.requestStatsUpdate(0 /* unused */));
-
         // finally, dispatch updated event to any listeners
         final Intent updatedIntent = new Intent(ACTION_NETWORK_STATS_UPDATED);
         updatedIntent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
@@ -1501,8 +1520,8 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         }
 
         @Override
-        public void setStatsProviderLimit(@NonNull String iface, long quota) {
+        public void setStatsProviderLimitAsync(@NonNull String iface, long quota) {
-            Slog.v(TAG, "setStatsProviderLimit(" + iface + "," + quota + ")");
+            Slog.v(TAG, "setStatsProviderLimitAsync(" + iface + "," + quota + ")");
             invokeForAllStatsProviderCallbacks((cb) -> cb.mProvider.setLimit(iface, quota));
         }
     }
@@ -1783,9 +1802,9 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
      * {@code unregister()} of the returned callback.
      *
      * @param tag a human readable identifier of the custom network stats provider.
-     * @param provider the binder interface of
+     * @param provider the {@link INetworkStatsProvider} binder corresponding to the
-     *                 {@link android.net.netstats.provider.AbstractNetworkStatsProvider} that
+     *                 {@link android.net.netstats.provider.AbstractNetworkStatsProvider} to be
-     *                 needs to be registered to the system.
+     *                 registered.
      *
      * @return a binder interface of
      *         {@link android.net.netstats.provider.NetworkStatsProviderCallback}, which can be
@@ -1798,7 +1817,8 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         Objects.requireNonNull(tag, "tag is null");
         try {
             NetworkStatsProviderCallbackImpl callback = new NetworkStatsProviderCallbackImpl(
-                            tag, provider, mAlertObserver, mStatsProviderCbList);
+                    tag, provider, mStatsProviderSem, mAlertObserver,
+                    mStatsProviderCbList);
             mStatsProviderCbList.register(callback);
             Log.d(TAG, "registerNetworkStatsProvider from " + callback.mTag + " uid/pid="
                     + getCallingUid() + "/" + getCallingPid());
@@ -1823,7 +1843,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
 
     private void invokeForAllStatsProviderCallbacks(
             @NonNull ThrowingConsumer<NetworkStatsProviderCallbackImpl, RemoteException> task) {
-        synchronized (mStatsProviderCbList) {
+        synchronized (mStatsLock) {
             final int length = mStatsProviderCbList.beginBroadcast();
             try {
                 for (int i = 0; i < length; i++) {
@@ -1844,25 +1864,30 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     private static class NetworkStatsProviderCallbackImpl extends INetworkStatsProviderCallback.Stub
             implements IBinder.DeathRecipient {
         @NonNull final String mTag;
-        @NonNull private final Object mProviderStatsLock = new Object();
+
         @NonNull final INetworkStatsProvider mProvider;
+        @NonNull private final Semaphore mSemaphore;
         @NonNull final INetworkManagementEventObserver mAlertObserver;
         @NonNull final RemoteCallbackList<NetworkStatsProviderCallbackImpl> mStatsProviderCbList;
 
+        @NonNull private final Object mProviderStatsLock = new Object();
+
         @GuardedBy("mProviderStatsLock")
-        // STATS_PER_IFACE and STATS_PER_UID
+        // Track STATS_PER_IFACE and STATS_PER_UID separately.
         private final NetworkStats mIfaceStats = new NetworkStats(0L, 0);
         @GuardedBy("mProviderStatsLock")
         private final NetworkStats mUidStats = new NetworkStats(0L, 0);
 
         NetworkStatsProviderCallbackImpl(
                 @NonNull String tag, @NonNull INetworkStatsProvider provider,
+                @NonNull Semaphore semaphore,
                 @NonNull INetworkManagementEventObserver alertObserver,
                 @NonNull RemoteCallbackList<NetworkStatsProviderCallbackImpl> cbList)
                 throws RemoteException {
             mTag = tag;
             mProvider = provider;
             mProvider.asBinder().linkToDeath(this, 0);
+            mSemaphore = semaphore;
             mAlertObserver = alertObserver;
             mStatsProviderCbList = cbList;
         }
@@ -1881,7 +1906,8 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
                     default:
                         throw new IllegalArgumentException("Invalid type: " + how);
                 }
-                // Return a defensive copy instead of local reference.
+                // Callers might be able to mutate the returned object. Return a defensive copy
+                // instead of local reference.
                 return stats.clone();
             }
         }
@@ -1895,6 +1921,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
                 if (ifaceStats != null) mIfaceStats.combineAllValues(ifaceStats);
                 if (uidStats != null) mUidStats.combineAllValues(uidStats);
             }
+            mSemaphore.release();
         }
 
         @Override