DO NOT MERGE: Associate notif cancels with notif posts am: 24a1d2c990

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13473406

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I074d7d635db77155b96ba0a457ec26d7c471de79

7 files changed, 547 insertions, 112 deletions

diff --git a/services/core/java/com/android/server/notification/InjectableSystemClock.java b/services/core/java/com/android/server/notification/InjectableSystemClock.java
new file mode 100644
index 000000000000..4d993d19e57b
--- /dev/null
+++ b/services/core/java/com/android/server/notification/InjectableSystemClock.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2020 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.server.notification;
+
+/**
+ * Testable wrapper around {@link android.os.SystemClock}.
+ *
+ * The default implementation at InjectableSystemClockImpl just proxies calls to the real
+ * SystemClock
+ *
+ * In tests, pass an instance of FakeSystemClock, which allows you to control the values returned by
+ * the various getters below.
+ */
+public interface InjectableSystemClock {
+    /** @see android.os.SystemClock#uptimeMillis() */
+    long uptimeMillis();
+
+    /** @see android.os.SystemClock#elapsedRealtime() */
+    long elapsedRealtime();
+
+    /** @see android.os.SystemClock#elapsedRealtimeNanos() */
+    long elapsedRealtimeNanos();
+
+    /** @see android.os.SystemClock#currentThreadTimeMillis() */
+    long currentThreadTimeMillis();
+
+    /** @see System#currentTimeMillis()  */
+    long currentTimeMillis();
+}
+
diff --git a/services/core/java/com/android/server/notification/InjectableSystemClockImpl.java b/services/core/java/com/android/server/notification/InjectableSystemClockImpl.java
new file mode 100644
index 000000000000..43d756f46176
--- /dev/null
+++ b/services/core/java/com/android/server/notification/InjectableSystemClockImpl.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2020 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.server.notification;
+
+/**
+ * Default implementation of {@link InjectableSystemClock}.
+ *
+ * @hide
+ */
+public class InjectableSystemClockImpl implements InjectableSystemClock {
+    public InjectableSystemClockImpl() {}
+
+    @Override
+    public long uptimeMillis() {
+        return android.os.SystemClock.uptimeMillis();
+    }
+
+    @Override
+    public long elapsedRealtime() {
+        return android.os.SystemClock.elapsedRealtime();
+    }
+
+    @Override
+    public long elapsedRealtimeNanos() {
+        return android.os.SystemClock.elapsedRealtimeNanos();
+    }
+
+    @Override
+    public long currentThreadTimeMillis() {
+        return android.os.SystemClock.currentThreadTimeMillis();
+    }
+
+    @Override
+    public long currentTimeMillis() {
+        return System.currentTimeMillis();
+    }
+}
diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index 2fe783387e23..e94507bccea0 100755
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -186,7 +186,6 @@ import android.os.RemoteException;
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
 import android.os.ShellCallback;
-import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
@@ -472,6 +471,11 @@ public class NotificationManagerService extends SystemService {
     final ArrayMap<Integer, ArrayMap<String, String>> mAutobundledSummaries = new ArrayMap<>();
     final ArrayList<ToastRecord> mToastQueue = new ArrayList<>();
     final ArrayMap<String, NotificationRecord> mSummaryByGroupKey = new ArrayMap<>();
+    // Keep track of `CancelNotificationRunnable`s which have been delayed due to awaiting
+    // enqueued notifications to post
+    @GuardedBy("mNotificationLock")
+    final ArrayMap<NotificationRecord, ArrayList<CancelNotificationRunnable>> mDelayedCancelations =
+            new ArrayMap<>();
 
     // The last key in this list owns the hardware.
     ArrayList<String> mLights = new ArrayList<>();
@@ -534,6 +538,7 @@ public class NotificationManagerService extends SystemService {
     private NotificationRecordLogger mNotificationRecordLogger;
     private InstanceIdSequence mNotificationInstanceIdSequence;
     private Set<String> mMsgPkgsAllowedAsConvos = new HashSet();
+    private final InjectableSystemClock mSystemClock;
 
     static class Archive {
         final SparseArray<Boolean> mEnabled;
@@ -747,7 +752,7 @@ public class NotificationManagerService extends SystemService {
                         parser, mAllowedManagedServicePackages, forRestore, userId);
                 migratedManagedServices = true;
             } else if (mSnoozeHelper.XML_TAG_NAME.equals(parser.getName())) {
-                mSnoozeHelper.readXml(parser, System.currentTimeMillis());
+                mSnoozeHelper.readXml(parser, mSystemClock.currentTimeMillis());
             }
             if (LOCKSCREEN_ALLOW_SECURE_NOTIFICATIONS_TAG.equals(parser.getName())) {
                 if (forRestore && userId != UserHandle.USER_SYSTEM) {
@@ -900,7 +905,7 @@ public class NotificationManagerService extends SystemService {
                     Slog.w(TAG, "No notification with key: " + key);
                     return;
                 }
-                final long now = System.currentTimeMillis();
+                final long now = mSystemClock.currentTimeMillis();
                 MetricsLogger.action(r.getItemLogMaker()
                         .setType(MetricsEvent.TYPE_ACTION)
                         .addTaggedData(MetricsEvent.NOTIFICATION_SHADE_INDEX, nv.rank)
@@ -932,7 +937,7 @@ public class NotificationManagerService extends SystemService {
                     Slog.w(TAG, "No notification with key: " + key);
                     return;
                 }
-                final long now = System.currentTimeMillis();
+                final long now = mSystemClock.currentTimeMillis();
                 MetricsLogger.action(r.getLogMaker(now)
                         .setCategory(MetricsEvent.NOTIFICATION_ITEM_ACTION)
                         .setType(MetricsEvent.TYPE_ACTION)
@@ -1696,15 +1701,18 @@ public class NotificationManagerService extends SystemService {
     public NotificationManagerService(Context context) {
         this(context,
                 new NotificationRecordLoggerImpl(),
+                new InjectableSystemClockImpl(),
                 new InstanceIdSequence(NOTIFICATION_INSTANCE_ID_MAX));
     }
 
     @VisibleForTesting
     public NotificationManagerService(Context context,
             NotificationRecordLogger notificationRecordLogger,
+            InjectableSystemClock systemClock,
             InstanceIdSequence notificationInstanceIdSequence) {
         super(context);
         mNotificationRecordLogger = notificationRecordLogger;
+        mSystemClock = systemClock;
         mNotificationInstanceIdSequence = notificationInstanceIdSequence;
         Notification.processWhitelistToken = WHITELIST_TOKEN;
     }
@@ -2056,6 +2064,11 @@ public class NotificationManagerService extends SystemService {
         return getContext().getResources().getStringArray(key);
     }
 
+    @VisibleForTesting
+    protected Handler getWorkHandler() {
+        return mHandler;
+    }
+
     @Override
     public void onStart() {
         SnoozeHelper snoozeHelper = new SnoozeHelper(getContext(), (userId, r, muteOnReturn) -> {
@@ -2329,7 +2342,8 @@ public class NotificationManagerService extends SystemService {
             mHistoryManager.onBootPhaseAppsCanStart();
             registerDeviceConfigChange();
         } else if (phase == SystemService.PHASE_ACTIVITY_MANAGER_READY) {
-            mSnoozeHelper.scheduleRepostsForPersistedNotifications(System.currentTimeMillis());
+            mSnoozeHelper.scheduleRepostsForPersistedNotifications(
+                    mSystemClock.currentTimeMillis());
         }
     }
 
@@ -2689,7 +2703,7 @@ public class NotificationManagerService extends SystemService {
                         .setUserId(r.getSbn().getNormalizedUserId())
                         .setChannelId(r.getChannel().getId())
                         .setChannelName(r.getChannel().getName().toString())
-                        .setPostedTimeMs(System.currentTimeMillis())
+                        .setPostedTimeMs(mSystemClock.currentTimeMillis())
                         .setTitle(getHistoryTitle(r.getNotification()))
                         .setText(getHistoryText(
                                 r.getSbn().getPackageContext(getContext()), r.getNotification()))
@@ -5215,7 +5229,7 @@ public class NotificationManagerService extends SystemService {
                                 GroupHelper.AUTOGROUP_KEY, adjustedSbn.getUid(),
                                 adjustedSbn.getInitialPid(), summaryNotification,
                                 adjustedSbn.getUser(), GroupHelper.AUTOGROUP_KEY,
-                                System.currentTimeMillis());
+                                mSystemClock.currentTimeMillis());
                 summaryRecord = new NotificationRecord(getContext(), summarySbn,
                         notificationRecord.getChannel());
                 summaryRecord.setIsAppImportanceLocked(
@@ -5450,6 +5464,22 @@ public class NotificationManagerService extends SystemService {
 
                     mSnoozeHelper.dump(pw, filter);
                 }
+
+                // Log delayed notification cancels
+                pw.println();
+                pw.println("  Delayed notification cancels:");
+                if (mDelayedCancelations.isEmpty()) {
+                    pw.println("    None");
+                } else {
+                    Set<NotificationRecord> delayedKeys = mDelayedCancelations.keySet();
+                    for (NotificationRecord record : delayedKeys) {
+                        ArrayList<CancelNotificationRunnable> queuedCancels =
+                                mDelayedCancelations.get(record);
+                        pw.println("    (" + queuedCancels.size() + ") cancels enqueued for"
+                                + record.getKey());
+                    }
+                }
+                pw.println();
             }
 
             if (!zenOnly) {
@@ -5668,7 +5698,7 @@ public class NotificationManagerService extends SystemService {
 
         final StatusBarNotification n = new StatusBarNotification(
                 pkg, opPkg, id, tag, notificationUid, callingPid, notification,
-                user, null, System.currentTimeMillis());
+                user, null, mSystemClock.currentTimeMillis());
 
         // setup local book-keeping
         String channelId = notification.getChannelId();
@@ -6001,7 +6031,7 @@ public class NotificationManagerService extends SystemService {
                     final float appEnqueueRate = mUsageStats.getAppEnqueueRate(pkg);
                     if (appEnqueueRate > mMaxPackageEnqueueRate) {
                         mUsageStats.registerOverRateQuota(pkg);
-                        final long now = SystemClock.elapsedRealtime();
+                        final long now = mSystemClock.elapsedRealtime();
                         if ((now - mLastOverRateLogTime) > MIN_PACKAGE_OVERRATE_LOG_INTERVAL) {
                             Slog.e(TAG, "Package enqueue rate is " + appEnqueueRate
                                     + ". Shedding " + r.getSbn().getKey() + ". package=" + pkg);
@@ -6213,7 +6243,73 @@ public class NotificationManagerService extends SystemService {
             this.mRank = rank;
             this.mCount = count;
             this.mListener = listener;
-            this.mWhen = System.currentTimeMillis();
+            this.mWhen = mSystemClock.currentTimeMillis();
+        }
+
+        // Move the work to this function so it can be called from PostNotificationRunnable
+        private void doNotificationCancelLocked() {
+            // Look for the notification in the posted list, since we already checked enqueued.
+            String listenerName = mListener == null ? null : mListener.component.toShortString();
+            NotificationRecord r =
+                    findNotificationByListLocked(mNotificationList, mPkg, mTag, mId, mUserId);
+            if (r != null) {
+                // The notification was found, check if it should be removed.
+
+                // Ideally we'd do this in the caller of this method. However, that would
+                // require the caller to also find the notification.
+                if (mReason == REASON_CLICK) {
+                    mUsageStats.registerClickedByUser(r);
+                }
+
+                if (mReason == REASON_LISTENER_CANCEL
+                        && (r.getNotification().flags & FLAG_BUBBLE) != 0) {
+                    mNotificationDelegate.onBubbleNotificationSuppressionChanged(
+                            r.getKey(), /* suppressed */ true);
+                    return;
+                }
+
+                if ((r.getNotification().flags & mMustHaveFlags) != mMustHaveFlags) {
+                    return;
+                }
+                if ((r.getNotification().flags & mMustNotHaveFlags) != 0) {
+                    return;
+                }
+
+                // Bubbled children get to stick around if the summary was manually cancelled
+                // (user removed) from systemui.
+                FlagChecker childrenFlagChecker = null;
+                if (mReason == REASON_CANCEL
+                        || mReason == REASON_CLICK
+                        || mReason == REASON_CANCEL_ALL) {
+                    childrenFlagChecker = (flags) -> {
+                        if ((flags & FLAG_BUBBLE) != 0) {
+                            return false;
+                        }
+                        return true;
+                    };
+                }
+
+                // Cancel the notification.
+                boolean wasPosted = removePreviousFromNotificationListsLocked(r, mWhen);
+                cancelNotificationLocked(
+                        r, mSendDelete, mReason, mRank, mCount, wasPosted, listenerName);
+                cancelGroupChildrenLocked(r, mCallingUid, mCallingPid, listenerName,
+                        mSendDelete, childrenFlagChecker, mReason);
+                updateLightsLocked();
+                if (mShortcutHelper != null) {
+                    mShortcutHelper.maybeListenForShortcutChangesForBubbles(r,
+                            true /* isRemoved */,
+                            mHandler);
+                }
+            } else {
+                // No notification was found, assume that it is snoozed and cancel it.
+                if (mReason != REASON_SNOOZED) {
+                    final boolean wasSnoozed = mSnoozeHelper.cancel(mUserId, mPkg, mTag, mId);
+                    if (wasSnoozed) {
+                        handleSavePolicyFile();
+                    }
+                }
+            }
         }
 
         @Override
@@ -6229,89 +6325,24 @@ public class NotificationManagerService extends SystemService {
                 // chance to post yet.
                 List<NotificationRecord> enqueued = findEnqueuedNotificationsForCriteria(
                         mPkg, mTag, mId, mUserId);
-                boolean repost = false;
                 if (enqueued.size() > 0) {
-                    // Found something, let's see what it was
-                    repost = true;
-                    // If all enqueues happened before this cancel then wait for them to happen,
-                    // otherwise we should let this cancel through so the next enqueue happens
-                    for (NotificationRecord r : enqueued) {
-                        if (r.mUpdateTimeMs > mWhen) {
-                            // At least one enqueue was posted after the cancel, so we're invalid
-                            return;
-                        }
+                    // We have found notifications that were enqueued before this cancel, but not
+                    // yet posted. Attach this cancel to the last enqueue (the most recent), and
+                    // we will be executed in that notification's PostNotificationRunnable
+                    NotificationRecord enqueuedToAttach = enqueued.get(enqueued.size() - 1);
+
+                    ArrayList<CancelNotificationRunnable> delayed =
+                            mDelayedCancelations.get(enqueuedToAttach);
+                    if (delayed == null) {
+                        delayed = new ArrayList<>();
                     }
-                }
-                if (repost) {
-                    mHandler.post(this);
+
+                    delayed.add(this);
+                    mDelayedCancelations.put(enqueuedToAttach, delayed);
                     return;
                 }
 
-                // Look for the notification in the posted list, since we already checked enqueued.
-                NotificationRecord r =
-                        findNotificationByListLocked(mNotificationList, mPkg, mTag, mId, mUserId);
-                if (r != null) {
-                    // The notification was found, check if it should be removed.
-
-                    // Ideally we'd do this in the caller of this method. However, that would
-                    // require the caller to also find the notification.
-                    if (mReason == REASON_CLICK) {
-                        mUsageStats.registerClickedByUser(r);
-                    }
-
-                    if (mReason == REASON_LISTENER_CANCEL
-                        && (r.getNotification().flags & FLAG_BUBBLE) != 0) {
-                        mNotificationDelegate.onBubbleNotificationSuppressionChanged(
-                            r.getKey(), /* suppressed */ true);
-                        return;
-                    }
-
-                    if ((r.getNotification().flags & mMustHaveFlags) != mMustHaveFlags) {
-                        return;
-                    }
-                    if ((r.getNotification().flags & mMustNotHaveFlags) != 0) {
-                        return;
-                    }
-                    if (r.getUpdateTimeMs() > mWhen) {
-                        // In this case, a post must have slipped by when this runnable reposted
-                        return;
-                    }
-
-                    // Bubbled children get to stick around if the summary was manually cancelled
-                    // (user removed) from systemui.
-                    FlagChecker childrenFlagChecker = null;
-                    if (mReason == REASON_CANCEL
-                            || mReason == REASON_CLICK
-                            || mReason == REASON_CANCEL_ALL) {
-                        childrenFlagChecker = (flags) -> {
-                            if ((flags & FLAG_BUBBLE) != 0) {
-                                return false;
-                            }
-                            return true;
-                        };
-                    }
-
-                    // Cancel the notification.
-                    boolean wasPosted = removeFromNotificationListsLocked(r);
-                    cancelNotificationLocked(
-                            r, mSendDelete, mReason, mRank, mCount, wasPosted, listenerName);
-                    cancelGroupChildrenLocked(r, mCallingUid, mCallingPid, listenerName,
-                            mSendDelete, childrenFlagChecker, mReason);
-                    updateLightsLocked();
-                    if (mShortcutHelper != null) {
-                        mShortcutHelper.maybeListenForShortcutChangesForBubbles(r,
-                                true /* isRemoved */,
-                                mHandler);
-                    }
-                } else {
-                    // No notification was found, assume that it is snoozed and cancel it.
-                    if (mReason != REASON_SNOOZED) {
-                        final boolean wasSnoozed = mSnoozeHelper.cancel(mUserId, mPkg, mTag, mId);
-                        if (wasSnoozed) {
-                            handleSavePolicyFile();
-                        }
-                    }
-                }
+                doNotificationCancelLocked();
             }
         }
     }
@@ -6334,7 +6365,7 @@ public class NotificationManagerService extends SystemService {
                         mSnoozeHelper.getSnoozeTimeForUnpostedNotification(
                                 r.getUser().getIdentifier(),
                                 r.getSbn().getPackageName(), r.getSbn().getKey());
-                final long currentTime = System.currentTimeMillis();
+                final long currentTime = mSystemClock.currentTimeMillis();
                 if (snoozeAt.longValue() > currentTime) {
                     (new SnoozeNotificationRunnable(r.getSbn().getKey(),
                             snoozeAt.longValue() - currentTime, null)).snoozeLocked(r);
@@ -6394,18 +6425,29 @@ public class NotificationManagerService extends SystemService {
                             enqueueStatus);
                 }
 
-                // tell the assistant service about the notification
-                if (mAssistants.isEnabled()) {
-                    mAssistants.onNotificationEnqueuedLocked(r);
-                    mHandler.postDelayed(new PostNotificationRunnable(r.getKey()),
-                            DELAY_FOR_ASSISTANT_TIME);
-                } else {
-                    mHandler.post(new PostNotificationRunnable(r.getKey()));
-                }
+                postPostNotificationRunnableMaybeDelayedLocked(
+                        r, new PostNotificationRunnable(r.getKey()));
             }
         }
     }
 
+    /**
+     * Mainly needed as a hook for tests which require setting up enqueued-but-not-posted
+     * notification records
+     */
+    @GuardedBy("mNotificationLock")
+    protected void postPostNotificationRunnableMaybeDelayedLocked(
+            NotificationRecord r,
+            PostNotificationRunnable runnable) {
+        // tell the assistant service about the notification
+        if (mAssistants.isEnabled()) {
+            mAssistants.onNotificationEnqueuedLocked(r);
+            mHandler.postDelayed(runnable, DELAY_FOR_ASSISTANT_TIME);
+        } else {
+            mHandler.post(runnable);
+        }
+    }
+
     @GuardedBy("mNotificationLock")
     boolean isPackagePausedOrSuspended(String pkg, int uid) {
         boolean isPaused;
@@ -6554,13 +6596,23 @@ public class NotificationManagerService extends SystemService {
                             buzzBeepBlinkLoggingCode, getGroupInstanceId(n.getGroupKey()));
                 } finally {
                     int N = mEnqueuedNotifications.size();
+                    NotificationRecord enqueued = null;
                     for (int i = 0; i < N; i++) {
-                        final NotificationRecord enqueued = mEnqueuedNotifications.get(i);
+                        enqueued = mEnqueuedNotifications.get(i);
                         if (Objects.equals(key, enqueued.getKey())) {
                             mEnqueuedNotifications.remove(i);
                             break;
                         }
                     }
+
+                    // If the enqueued notification record had a cancel attached after it, execute
+                    // it right now
+                    if (enqueued != null && mDelayedCancelations.get(enqueued) != null) {
+                        for (CancelNotificationRunnable r : mDelayedCancelations.get(enqueued)) {
+                            r.doNotificationCancelLocked();
+                        }
+                        mDelayedCancelations.remove(enqueued);
+                    }
                 }
             }
         }
@@ -6789,7 +6841,8 @@ public class NotificationManagerService extends SystemService {
                             .putExtra(EXTRA_KEY, record.getKey()),
                     PendingIntent.FLAG_UPDATE_CURRENT);
             mAlarmManager.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP,
-                    SystemClock.elapsedRealtime() + record.getNotification().getTimeoutAfter(), pi);
+                    mSystemClock.elapsedRealtime() + record.getNotification().getTimeoutAfter(),
+                    pi);
         }
     }
 
@@ -7310,7 +7363,7 @@ public class NotificationManagerService extends SystemService {
                     || visibilityChanged
                     || interruptiveChanged;
             if (interceptBefore && !record.isIntercepted()
-                    && record.isNewEnoughForAlerting(System.currentTimeMillis())) {
+                    && record.isNewEnoughForAlerting(mSystemClock.currentTimeMillis())) {
                 buzzBeepBlinkLocked(record);
             }
         }
@@ -7597,6 +7650,34 @@ public class NotificationManagerService extends SystemService {
         return wasPosted;
     }
 
+    /**
+     * Similar to the above method, removes all NotificationRecords with the same key as the given
+     * NotificationRecord, but skips any records which are newer than the given one.
+     */
+    private boolean removePreviousFromNotificationListsLocked(NotificationRecord r,
+            long removeBefore) {
+        // Remove notification records that occurred before the given record from both lists,
+        // specifically allowing newer ones to respect ordering
+        boolean wasPosted = false;
+        List<NotificationRecord> matching =
+                findNotificationsByListLocked(mNotificationList, r.getKey());
+        for (NotificationRecord record : matching) {
+            // We don't need to check against update time for posted notifs
+            mNotificationList.remove(record);
+            mNotificationsByKey.remove(record.getSbn().getKey());
+            wasPosted = true;
+        }
+
+        matching = findNotificationsByListLocked(mEnqueuedNotifications, r.getKey());
+        for (NotificationRecord record : matching) {
+            if (record.getUpdateTimeMs() <= removeBefore) {
+                mNotificationList.remove(record);
+            }
+        }
+
+        return wasPosted;
+    }
+
     @GuardedBy("mNotificationLock")
     private void cancelNotificationLocked(NotificationRecord r, boolean sendDelete,
             @NotificationListenerService.NotificationCancelReason int reason,
@@ -7712,7 +7793,7 @@ public class NotificationManagerService extends SystemService {
         // Save it for users of getHistoricalNotifications()
         mArchive.record(r.getSbn(), reason);
 
-        final long now = System.currentTimeMillis();
+        final long now = mSystemClock.currentTimeMillis();
         final LogMaker logMaker = r.getItemLogMaker()
                 .setType(MetricsEvent.TYPE_DISMISS)
                 .setSubtype(reason);
@@ -8246,6 +8327,21 @@ public class NotificationManagerService extends SystemService {
         return null;
     }
 
+    @GuardedBy("mNotificationLock")
+    private List<NotificationRecord> findNotificationsByListLocked(
+            ArrayList<NotificationRecord> list,
+            String key) {
+        List<NotificationRecord> matching = new ArrayList<>();
+        final int n = list.size();
+        for (int i = 0; i < n; i++) {
+            NotificationRecord r = list.get(i);
+            if (key.equals(r.getKey())) {
+                matching.add(r);
+            }
+        }
+        return matching;
+    }
+
     /**
      * There may be multiple records that match your criteria. For instance if there have been
      * multiple notifications posted which are enqueued for the same pkg, tag, id, userId. This
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/BuzzBeepBlinkTest.java b/services/tests/uiservicestests/src/com/android/server/notification/BuzzBeepBlinkTest.java
index afd10ddb8ec2..2e0f1992478d 100644
--- a/services/tests/uiservicestests/src/com/android/server/notification/BuzzBeepBlinkTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/BuzzBeepBlinkTest.java
@@ -103,6 +103,7 @@ public class BuzzBeepBlinkTest extends UiServiceTestCase {
     NotificationRecordLoggerFake mNotificationRecordLogger = new NotificationRecordLoggerFake();
     private InstanceIdSequence mNotificationInstanceIdSequence = new InstanceIdSequenceFake(
             1 << 30);
+    private InjectableSystemClock mSystemClock = new FakeSystemClock();
 
     private NotificationManagerService mService;
     private String mPkg = "com.android.server.notification";
@@ -154,7 +155,7 @@ public class BuzzBeepBlinkTest extends UiServiceTestCase {
         assertTrue(accessibilityManager.isEnabled());
 
         mService = spy(new NotificationManagerService(getContext(), mNotificationRecordLogger,
-                mNotificationInstanceIdSequence));
+                mSystemClock, mNotificationInstanceIdSequence));
         mService.setAudioManager(mAudioManager);
         mService.setVibrator(mVibrator);
         mService.setSystemReady(true);
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/FakeSystemClock.java b/services/tests/uiservicestests/src/com/android/server/notification/FakeSystemClock.java
new file mode 100644
index 000000000000..c960f1766612
--- /dev/null
+++ b/services/tests/uiservicestests/src/com/android/server/notification/FakeSystemClock.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2020 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.server.notification;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A fake {@link InjectableSystemClock}
+ *
+ * Attempts to simulate the behavior of a real system clock. Time can be moved forward but not
+ * backwards. uptimeMillis, elapsedRealtime, and currentThreadTimeMillis are all kept in sync.
+ *
+ * Unless otherwise specified, uptimeMillis and elapsedRealtime will advance the same amount with
+ * every call to {@link #advanceTime(long)}. Thread time always lags by 50% of the uptime
+ * advancement to simulate time loss due to scheduling.
+ *
+ * @hide
+ */
+public class FakeSystemClock implements InjectableSystemClock {
+    private long mUptimeMillis = 10000;
+    private long mElapsedRealtime = 10000;
+    private long mCurrentThreadTimeMillis = 10000;
+
+    private long mCurrentTimeMillis = 1555555500000L;
+
+    private final List<ClockTickListener> mListeners = new ArrayList<>();
+    @Override
+    public long uptimeMillis() {
+        return mUptimeMillis;
+    }
+
+    @Override
+    public long elapsedRealtime() {
+        return mElapsedRealtime;
+    }
+
+    @Override
+    public long elapsedRealtimeNanos() {
+        return mElapsedRealtime * 1000000 + 447;
+    }
+
+    @Override
+    public long currentThreadTimeMillis() {
+        return mCurrentThreadTimeMillis;
+    }
+
+    @Override
+    public long currentTimeMillis() {
+        return mCurrentTimeMillis;
+    }
+
+    public void setUptimeMillis(long uptime) {
+        advanceTime(uptime - mUptimeMillis);
+    }
+
+    public void setCurrentTimeMillis(long millis) {
+        mCurrentTimeMillis = millis;
+    }
+
+    public void advanceTime(long uptime) {
+        advanceTime(uptime, 0);
+    }
+
+    public void advanceTime(long uptime, long sleepTime) {
+        if (uptime < 0 || sleepTime < 0) {
+            throw new IllegalArgumentException("Time cannot go backwards.");
+        }
+
+        if (uptime > 0 || sleepTime > 0) {
+            mUptimeMillis += uptime;
+            mElapsedRealtime += uptime + sleepTime;
+            mCurrentTimeMillis += uptime + sleepTime;
+
+            mCurrentThreadTimeMillis += Math.ceil(uptime * 0.5);
+
+            for (ClockTickListener listener : mListeners) {
+                listener.onClockTick();
+            }
+        }
+    }
+
+    public void addListener(ClockTickListener listener) {
+        mListeners.add(listener);
+    }
+
+    public void removeListener(ClockTickListener listener) {
+        mListeners.remove(listener);
+    }
+
+    public interface ClockTickListener {
+        void onClockTick();
+    }
+
+    private static final long START_TIME = 10000;
+}
+
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
index 16aa87b3e59c..a55d28ee6065 100755
--- a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
@@ -178,7 +178,6 @@ import com.android.server.wm.WindowManagerInternal;
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
@@ -199,6 +198,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.function.Consumer;
 
 
@@ -287,18 +287,26 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
             1 << 30);
     @Mock
     StatusBarManagerInternal mStatusBar;
+    private final FakeSystemClock mSystemClock = new FakeSystemClock();
 
     // Use a Testable subclass so we can simulate calls from the system without failing.
     private static class TestableNotificationManagerService extends NotificationManagerService {
         int countSystemChecks = 0;
         boolean isSystemUid = true;
         int countLogSmartSuggestionsVisible = 0;
+        // If true, don't enqueue the PostNotificationRunnables, just trap them
+        boolean trapEnqueuedNotifications = false;
+        final ArrayList<NotificationManagerService.PostNotificationRunnable> trappedRunnables =
+                new ArrayList<>();
         @Nullable
         NotificationAssistantAccessGrantedCallback mNotificationAssistantAccessGrantedCallback;
 
-        TestableNotificationManagerService(Context context, NotificationRecordLogger logger,
+        TestableNotificationManagerService(
+                Context context,
+                NotificationRecordLogger logger,
+                InjectableSystemClock systemClock,
                 InstanceIdSequence notificationInstanceIdSequence) {
-            super(context, logger, notificationInstanceIdSequence);
+            super(context, logger, systemClock, notificationInstanceIdSequence);
         }
 
         RankingHelper getRankingHelper() {
@@ -353,6 +361,23 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
             return new String[] {PKG_O};
         }
 
+        @Override
+        protected void postPostNotificationRunnableMaybeDelayedLocked(NotificationRecord record,
+                PostNotificationRunnable runnable) {
+            if (trapEnqueuedNotifications) {
+                trappedRunnables.add(runnable);
+                return;
+            }
+
+            super.postPostNotificationRunnableMaybeDelayedLocked(record, runnable);
+        }
+
+        void drainTrappedRunnableQueue() {
+            for (Runnable r : trappedRunnables) {
+                getWorkHandler().post(r);
+            }
+        }
+
         private void setNotificationAssistantAccessGrantedCallback(
                 @Nullable NotificationAssistantAccessGrantedCallback callback) {
             this.mNotificationAssistantAccessGrantedCallback = callback;
@@ -402,7 +427,7 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
         doNothing().when(mContext).sendBroadcastAsUser(any(), any(), any());
 
         mService = new TestableNotificationManagerService(mContext, mNotificationRecordLogger,
-                mNotificationInstanceIdSequence);
+                mSystemClock, mNotificationInstanceIdSequence);
 
         // Use this testable looper.
         mTestableLooper = TestableLooper.get(this);
@@ -1344,10 +1369,10 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
         final StatusBarNotification sbn = generateNotificationRecord(null).getSbn();
         mBinderService.enqueueNotificationWithTag(PKG, PKG, "tag", sbn.getId(),
                 sbn.getNotification(), sbn.getUserId());
-        Thread.sleep(1);  // make sure the system clock advances before the next step
+        mSystemClock.advanceTime(1);
         // THEN it is canceled
         mBinderService.cancelNotificationWithTag(PKG, PKG, "tag", sbn.getId(), sbn.getUserId());
-        Thread.sleep(1);  // here too
+        mSystemClock.advanceTime(1);
         // THEN it is posted again (before the cancel has a chance to finish)
         mBinderService.enqueueNotificationWithTag(PKG, PKG, "tag", sbn.getId(),
                 sbn.getNotification(), sbn.getUserId());
@@ -1362,6 +1387,60 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
     }
 
     @Test
+    public void testChangeSystemTimeAfterPost_thenCancel_noFgs() throws Exception {
+        // GIVEN time X
+        mSystemClock.setCurrentTimeMillis(10000);
+
+        // GIVEN a notification is posted
+        final StatusBarNotification sbn = generateNotificationRecord(null).getSbn();
+        mBinderService.enqueueNotificationWithTag(PKG, PKG, "tag", sbn.getId(),
+                sbn.getNotification(), sbn.getUserId());
+        mSystemClock.advanceTime(1);
+        waitForIdle();
+
+        // THEN the system time is changed to an earlier time
+        mSystemClock.setCurrentTimeMillis(5000);
+
+        // THEN a cancel is requested
+        mBinderService.cancelNotificationWithTag(PKG, PKG, "tag", sbn.getId(), sbn.getUserId());
+        waitForIdle();
+
+        // It should work
+        StatusBarNotification[] notifs =
+                mBinderService.getActiveNotifications(PKG);
+        assertEquals(0, notifs.length);
+        assertEquals(0, mService.getNotificationRecordCount());
+    }
+
+    @Test
+    public void testChangeSystemTimeAfterPost_thenCancel_fgs() throws Exception {
+        // GIVEN time X
+        mSystemClock.setCurrentTimeMillis(10000);
+
+        // GIVEN a notification is posted
+        final StatusBarNotification sbn = generateNotificationRecord(null).getSbn();
+        sbn.getNotification().flags =
+                Notification.FLAG_ONGOING_EVENT | FLAG_FOREGROUND_SERVICE;
+        mBinderService.enqueueNotificationWithTag(PKG, PKG, "tag", sbn.getId(),
+                sbn.getNotification(), sbn.getUserId());
+        mSystemClock.advanceTime(1);
+        waitForIdle();
+
+        // THEN the system time is changed to an earlier time
+        mSystemClock.setCurrentTimeMillis(5000);
+
+        // THEN a cancel is requested
+        mBinderService.cancelNotificationWithTag(PKG, PKG, "tag", sbn.getId(), sbn.getUserId());
+        waitForIdle();
+
+        // It should work
+        StatusBarNotification[] notifs =
+                mBinderService.getActiveNotifications(PKG);
+        assertEquals(0, notifs.length);
+        assertEquals(0, mService.getNotificationRecordCount());
+    }
+
+    @Test
     public void testCancelNotificationWhilePostedAndEnqueued() throws Exception {
         mBinderService.enqueueNotificationWithTag(PKG, PKG,
                 "testCancelNotificationWhilePostedAndEnqueued", 0,
@@ -1383,6 +1462,56 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
     }
 
     @Test
+    public void testDelayCancelWhenEnqueuedHasNotPosted() throws Exception {
+        // Don't allow PostNotificationRunnables to execute so we can set up problematic state
+        mService.trapEnqueuedNotifications = true;
+        // GIVEN an enqueued notification
+        mBinderService.enqueueNotificationWithTag(PKG, PKG,
+                "testDelayCancelWhenEnqueuedHasNotPosted", 0,
+                generateNotificationRecord(null).getNotification(), 0);
+        mSystemClock.advanceTime(1);
+        // WHEN a cancel is requested before it has posted
+        mBinderService.cancelNotificationWithTag(PKG, PKG,
+                "testDelayCancelWhenEnqueuedHasNotPosted", 0, 0);
+
+        waitForIdle();
+
+        // THEN the cancel notification runnable is captured and associated with that record
+        ArrayMap<NotificationRecord,
+                ArrayList<NotificationManagerService.CancelNotificationRunnable>> delayed =
+                        mService.mDelayedCancelations;
+        Set<NotificationRecord> keySet = delayed.keySet();
+        assertEquals(1, keySet.size());
+    }
+
+    @Test
+    public void testDelayedCancelsExecuteAfterPost() throws Exception {
+        // Don't allow PostNotificationRunnables to execute so we can set up problematic state
+        mService.trapEnqueuedNotifications = true;
+        // GIVEN an enqueued notification
+        mBinderService.enqueueNotificationWithTag(PKG, PKG,
+                "testDelayCancelWhenEnqueuedHasNotPosted", 0,
+                generateNotificationRecord(null).getNotification(), 0);
+        mSystemClock.advanceTime(1);
+        // WHEN a cancel is requested before it has posted
+        mBinderService.cancelNotificationWithTag(PKG, PKG,
+                "testDelayCancelWhenEnqueuedHasNotPosted", 0, 0);
+
+        waitForIdle();
+
+        // We're now in a state with an a notification awaiting PostNotificationRunnable to execute
+        // WHEN the PostNotificationRunnable is allowed to execute
+        mService.drainTrappedRunnableQueue();
+        waitForIdle();
+
+        // THEN the cancel executes and the notification is removed
+        StatusBarNotification[] notifs =
+                mBinderService.getActiveNotifications(PKG);
+        assertEquals(0, notifs.length);
+        assertEquals(0, mService.getNotificationRecordCount());
+    }
+
+    @Test
     public void testCancelNotificationsFromListenerImmediatelyAfterEnqueue() throws Exception {
         NotificationRecord r = generateNotificationRecord(null);
         final StatusBarNotification sbn = r.getSbn();
@@ -2529,8 +2658,9 @@ public class NotificationManagerServiceTest extends UiServiceTestCase {
 
     @Test
     public void testHasCompanionDevice_noService() {
-        mService = new TestableNotificationManagerService(mContext,  mNotificationRecordLogger,
-                mNotificationInstanceIdSequence);
+        mService =
+                new TestableNotificationManagerService(mContext, mNotificationRecordLogger,
+                mSystemClock, mNotificationInstanceIdSequence);
 
         assertFalse(mService.hasCompanionDevice(mListener));
     }
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/RoleObserverTest.java b/services/tests/uiservicestests/src/com/android/server/notification/RoleObserverTest.java
index 3281c3f4cfb9..ac2c6193c677 100644
--- a/services/tests/uiservicestests/src/com/android/server/notification/RoleObserverTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/RoleObserverTest.java
@@ -103,12 +103,14 @@ public class RoleObserverTest extends UiServiceTestCase {
     private InstanceIdSequence mNotificationInstanceIdSequence = new InstanceIdSequenceFake(
             1 << 30);
     private List<UserInfo> mUsers;
+    private InjectableSystemClock mSystemClock = new FakeSystemClock();
 
     private static class TestableNotificationManagerService extends NotificationManagerService {
         TestableNotificationManagerService(Context context,
                 NotificationRecordLogger logger,
+                InjectableSystemClock systemClock,
                 InstanceIdSequence notificationInstanceIdSequence) {
-            super(context, logger, notificationInstanceIdSequence);
+            super(context, logger, systemClock, notificationInstanceIdSequence);
         }
 
         @Override
@@ -136,7 +138,7 @@ public class RoleObserverTest extends UiServiceTestCase {
         when(mUm.getUsers()).thenReturn(mUsers);
 
         mService = new TestableNotificationManagerService(mContext, mNotificationRecordLogger,
-                mNotificationInstanceIdSequence);
+                mSystemClock, mNotificationInstanceIdSequence);
         mRoleObserver = mService.new RoleObserver(mRoleManager, mPm, mExecutor);
 
         try {