Files
app_Settings/src/com/android/settings/homepage/contextualcards/EligibleCardChecker.java
Jason Chiu 73afb042dc Workaround of Slice not pinned bug when using SliceCallback
When a client registers a SliceCallback, it starts to observe Slice
changes. The observer is running in the main looper and binds Slice
in AsyncTask.

However, when the client unregisters the callback, it unpins the Slice
in the client's thread. Thus, if the AsyncTask has pinned the slice but
hasn't bound it yet, it may be unpinned by the client, and an exception
occurs.

This fix is to unpin the Slice in the same SerialExecutor of AsyncTask,
which is to ensure bindSlice() and unpinSlice() are called in the same
thread one after another without the race condition.

Bug: 157387583
Test: robotest
Change-Id: If5f4b4bc0d8c5a2800cad8ff2afd7084426a6c96
2020-06-22 07:38:50 +00:00

138 lines
4.6 KiB
Java

/*
* Copyright (C) 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.settings.homepage.contextualcards;
import static android.app.slice.Slice.HINT_ERROR;
import android.app.settings.SettingsEnums;
import android.content.ContentResolver;
import android.content.Context;
import android.net.Uri;
import android.os.AsyncTask;
import android.util.Log;
import androidx.annotation.VisibleForTesting;
import androidx.slice.Slice;
import androidx.slice.SliceMetadata;
import androidx.slice.SliceViewManager;
import androidx.slice.core.SliceAction;
import com.android.settings.overlay.FeatureFactory;
import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
import com.android.settingslib.utils.ThreadUtils;
import java.util.List;
import java.util.concurrent.Callable;
public class EligibleCardChecker implements Callable<ContextualCard> {
private static final String TAG = "EligibleCardChecker";
private final Context mContext;
@VisibleForTesting
ContextualCard mCard;
EligibleCardChecker(Context context, ContextualCard card) {
mContext = context;
mCard = card;
}
@Override
public ContextualCard call() {
final long startTime = System.currentTimeMillis();
final MetricsFeatureProvider metricsFeatureProvider =
FeatureFactory.getFactory(mContext).getMetricsFeatureProvider();
ContextualCard result;
if (isCardEligibleToDisplay(mCard)) {
metricsFeatureProvider.action(SettingsEnums.PAGE_UNKNOWN,
SettingsEnums.ACTION_CONTEXTUAL_CARD_ELIGIBILITY,
SettingsEnums.SETTINGS_HOMEPAGE,
mCard.getTextSliceUri() /* key */, 1 /* true */);
result = mCard;
} else {
metricsFeatureProvider.action(SettingsEnums.PAGE_UNKNOWN,
SettingsEnums.ACTION_CONTEXTUAL_CARD_ELIGIBILITY,
SettingsEnums.SETTINGS_HOMEPAGE,
mCard.getTextSliceUri() /* key */, 0 /* false */);
result = null;
}
// Log individual card loading time
metricsFeatureProvider.action(SettingsEnums.PAGE_UNKNOWN,
SettingsEnums.ACTION_CONTEXTUAL_CARD_LOAD,
SettingsEnums.SETTINGS_HOMEPAGE,
mCard.getTextSliceUri() /* key */,
(int) (System.currentTimeMillis() - startTime) /* value */);
return result;
}
@VisibleForTesting
boolean isCardEligibleToDisplay(ContextualCard card) {
if (card.getRankingScore() < 0) {
return false;
}
final Uri uri = card.getSliceUri();
if (!ContentResolver.SCHEME_CONTENT.equals(uri.getScheme())) {
return false;
}
final Slice slice = bindSlice(uri);
if (slice == null || slice.hasHint(HINT_ERROR)) {
Log.w(TAG, "Failed to bind slice, not eligible for display " + uri);
return false;
}
mCard = card.mutate().setSlice(slice).build();
if (isSliceToggleable(slice)) {
mCard = card.mutate().setHasInlineAction(true).build();
}
return true;
}
@VisibleForTesting
Slice bindSlice(Uri uri) {
final SliceViewManager manager = SliceViewManager.getInstance(mContext);
final SliceViewManager.SliceCallback callback = slice -> { };
// Register a trivial callback to pin the slice
manager.registerSliceCallback(uri, callback);
final Slice slice = manager.bindSlice(uri);
// Workaround of unpinning slice in the same SerialExecutor of AsyncTask as SliceCallback's
// observer.
ThreadUtils.postOnMainThread(() ->
AsyncTask.execute(() -> manager.unregisterSliceCallback(uri, callback))
);
return slice;
}
@VisibleForTesting
boolean isSliceToggleable(Slice slice) {
final SliceMetadata metadata = SliceMetadata.from(mContext, slice);
final List<SliceAction> toggles = metadata.getToggles();
return !toggles.isEmpty();
}
}