Fixing same pending update being sent every time startListening is called
if there was no widget update in-between

Bug: 67736800
Test: Added corresponding test in AppWidgetServiceImplTest
Change-Id: Ib3213f8f79ac11ed05b317e25110d7e37561b837
diff --git a/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java b/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
index a6aaaa67..51afada 100644
--- a/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
+++ b/services/appwidget/java/com/android/server/appwidget/AppWidgetServiceImpl.java
@@ -71,7 +71,6 @@
 import android.os.Trace;
 import android.os.UserHandle;
 import android.os.UserManager;
-import android.os.storage.StorageManager;
 import android.service.appwidget.AppWidgetServiceDumpProto;
 import android.service.appwidget.WidgetProto;
 import android.text.TextUtils;
@@ -159,7 +158,9 @@
     // Bump if the stored widgets need to be upgraded.
     private static final int CURRENT_VERSION = 1;
 
-    private static final AtomicLong REQUEST_COUNTER = new AtomicLong();
+    // Every widget update request is associated which an increasing sequence number. This is
+    // used to verify which request has successfully been received by the host.
+    private static final AtomicLong UPDATE_COUNTER = new AtomicLong();
 
     private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
         @Override
@@ -814,9 +815,9 @@
             Host host = lookupOrAddHostLocked(id);
             host.callbacks = callbacks;
 
+            long updateSequenceNo = UPDATE_COUNTER.incrementAndGet();
             int N = appWidgetIds.length;
             ArrayList<PendingHostUpdate> outUpdates = new ArrayList<>(N);
-
             LongSparseArray<PendingHostUpdate> updatesMap = new LongSparseArray<>();
             for (int i = 0; i < N; i++) {
                 if (host.getPendingUpdatesForId(appWidgetIds[i], updatesMap)) {
@@ -828,6 +829,8 @@
                     }
                 }
             }
+            // Reset the update counter once all the updates have been calculated
+            host.lastWidgetUpdateSequenceNo = updateSequenceNo;
             return new ParceledListSlice<>(outUpdates);
         }
     }
@@ -1914,9 +1917,9 @@
             // method with a wrong id. In that case, ignore the call.
             return;
         }
-        long requestId = REQUEST_COUNTER.incrementAndGet();
+        long requestId = UPDATE_COUNTER.incrementAndGet();
         if (widget != null) {
-            widget.updateRequestIds.put(viewId, requestId);
+            widget.updateSequenceNos.put(viewId, requestId);
         }
         if (widget == null || widget.host == null || widget.host.zombie
                 || widget.host.callbacks == null || widget.provider == null
@@ -1941,7 +1944,7 @@
             int appWidgetId, int viewId, long requestId) {
         try {
             callbacks.viewDataChanged(appWidgetId, viewId);
-            host.lastWidgetUpdateRequestId = requestId;
+            host.lastWidgetUpdateSequenceNo = requestId;
         } catch (RemoteException re) {
             // It failed; remove the callback. No need to prune because
             // we know that this host is still referenced by this instance.
@@ -1988,9 +1991,9 @@
     }
 
     private void scheduleNotifyUpdateAppWidgetLocked(Widget widget, RemoteViews updateViews) {
-        long requestId = REQUEST_COUNTER.incrementAndGet();
+        long requestId = UPDATE_COUNTER.incrementAndGet();
         if (widget != null) {
-            widget.updateRequestIds.put(ID_VIEWS_UPDATE, requestId);
+            widget.updateSequenceNos.put(ID_VIEWS_UPDATE, requestId);
         }
         if (widget == null || widget.provider == null || widget.provider.zombie
                 || widget.host.callbacks == null || widget.host.zombie) {
@@ -2013,7 +2016,7 @@
             int appWidgetId, RemoteViews views, long requestId) {
         try {
             callbacks.updateAppWidget(appWidgetId, views);
-            host.lastWidgetUpdateRequestId = requestId;
+            host.lastWidgetUpdateSequenceNo = requestId;
         } catch (RemoteException re) {
             synchronized (mLock) {
                 Slog.e(TAG, "Widget host dead: " + host.id, re);
@@ -2023,11 +2026,11 @@
     }
 
     private void scheduleNotifyProviderChangedLocked(Widget widget) {
-        long requestId = REQUEST_COUNTER.incrementAndGet();
+        long requestId = UPDATE_COUNTER.incrementAndGet();
         if (widget != null) {
             // When the provider changes, reset everything else.
-            widget.updateRequestIds.clear();
-            widget.updateRequestIds.append(ID_PROVIDER_CHANGED, requestId);
+            widget.updateSequenceNos.clear();
+            widget.updateSequenceNos.append(ID_PROVIDER_CHANGED, requestId);
         }
         if (widget == null || widget.provider == null || widget.provider.zombie
                 || widget.host.callbacks == null || widget.host.zombie) {
@@ -2050,7 +2053,7 @@
             int appWidgetId, AppWidgetProviderInfo info, long requestId) {
         try {
             callbacks.providerChanged(appWidgetId, info);
-            host.lastWidgetUpdateRequestId = requestId;
+            host.lastWidgetUpdateSequenceNo = requestId;
         } catch (RemoteException re) {
             synchronized (mLock){
                 Slog.e(TAG, "Widget host dead: " + host.id, re);
@@ -3887,7 +3890,11 @@
         boolean zombie; // if we're in safe mode, don't prune this just because nobody references it
 
         int tag = TAG_UNDEFINED; // for use while saving state (the index)
-        long lastWidgetUpdateRequestId; // request id for the last update successfully sent
+        // Sequence no for the last update successfully sent. This is updated whenever a
+        // widget update is successfully sent to the host callbacks. As all new/undelivered updates
+        // will have sequenceNo greater than this, all those updates will be sent when the host
+        // callbacks are attached again.
+        long lastWidgetUpdateSequenceNo;
 
         public int getUserId() {
             return UserHandle.getUserId(id.uid);
@@ -3914,18 +3921,18 @@
          */
         public boolean getPendingUpdatesForId(int appWidgetId,
                 LongSparseArray<PendingHostUpdate> outUpdates) {
-            long updateRequestId = lastWidgetUpdateRequestId;
+            long updateSequenceNo = lastWidgetUpdateSequenceNo;
             int N = widgets.size();
             for (int i = 0; i < N; i++) {
                 Widget widget = widgets.get(i);
                 if (widget.appWidgetId == appWidgetId) {
                     outUpdates.clear();
-                    for (int j = widget.updateRequestIds.size() - 1; j >= 0; j--) {
-                        long requestId = widget.updateRequestIds.valueAt(j);
-                        if (requestId <= updateRequestId) {
+                    for (int j = widget.updateSequenceNos.size() - 1; j >= 0; j--) {
+                        long requestId = widget.updateSequenceNos.valueAt(j);
+                        if (requestId <= updateSequenceNo) {
                             continue;
                         }
-                        int id = widget.updateRequestIds.keyAt(j);
+                        int id = widget.updateSequenceNos.keyAt(j);
                         final PendingHostUpdate update;
                         switch (id) {
                             case ID_PROVIDER_CHANGED:
@@ -4021,8 +4028,8 @@
         RemoteViews maskedViews;
         Bundle options;
         Host host;
-        // Request ids for various operations
-        SparseLongArray updateRequestIds = new SparseLongArray(2);
+        // Map of request type to updateSequenceNo.
+        SparseLongArray updateSequenceNos = new SparseLongArray(2);
 
         @Override
         public String toString() {
diff --git a/services/tests/servicestests/src/com/android/server/appwidget/AppWidgetServiceImplTest.java b/services/tests/servicestests/src/com/android/server/appwidget/AppWidgetServiceImplTest.java
index f4c4ea9..1bb93cc 100644
--- a/services/tests/servicestests/src/com/android/server/appwidget/AppWidgetServiceImplTest.java
+++ b/services/tests/servicestests/src/com/android/server/appwidget/AppWidgetServiceImplTest.java
@@ -247,6 +247,26 @@
         assertEquals(7, updates.size());
     }
 
+    public void testUpdatesReceived_queueEmptyAfterStartListening() {
+        int widgetId = setupHostAndWidget();
+        int widgetId2 = bindNewWidget();
+        mService.stopListening(mPkgName, HOST_ID);
+
+        sendDummyUpdates(widgetId, 22, 23);
+        sendDummyUpdates(widgetId2, 100, 101, 102);
+
+        List<PendingHostUpdate> updates = mService.startListening(
+                mMockHost, mPkgName, HOST_ID, new int[]{widgetId, widgetId2}).getList();
+        // 3 updates for first widget and 4 for second
+        assertEquals(7, updates.size());
+
+        // Stop and start listening again
+        mService.stopListening(mPkgName, HOST_ID);
+        updates = mService.startListening(
+                mMockHost, mPkgName, HOST_ID, new int[]{widgetId, widgetId2}).getList();
+        assertTrue(updates.isEmpty());
+    }
+
     public void testGetInstalledProvidersForPackage() {
         List<AppWidgetProviderInfo> allProviders = mManager.getInstalledProviders();
         assertTrue(!allProviders.isEmpty());