Add ThresholdAlarmQueue.

Add an AlarmQueue to track and update the controller when an app crosses
the "will be launched soon" threshold.

Bug: 194532703
Test: atest FrameworksMockingServicesTests:PrefetchControllerTest
Change-Id: Iaad45f5a5dddc75412ba3c802685399d98a05ad4

4 files changed, 181 insertions, 72 deletions

diff --git a/apex/jobscheduler/service/java/com/android/server/job/controllers/ComponentController.java b/apex/jobscheduler/service/java/com/android/server/job/controllers/ComponentController.java
index 98a39a65ae6c..aca381ff2043 100644
--- a/apex/jobscheduler/service/java/com/android/server/job/controllers/ComponentController.java
+++ b/apex/jobscheduler/service/java/com/android/server/job/controllers/ComponentController.java
@@ -113,7 +113,6 @@ public class ComponentController extends StateController {
         userFilter.addAction(Intent.ACTION_USER_STOPPED);
         mContext.registerReceiverAsUser(
                 mBroadcastReceiver, UserHandle.ALL, userFilter, null, null);
-
     }
 
     @Override
diff --git a/apex/jobscheduler/service/java/com/android/server/job/controllers/Package.java b/apex/jobscheduler/service/java/com/android/server/job/controllers/Package.java
new file mode 100644
index 000000000000..78a77fe46f3c
--- /dev/null
+++ b/apex/jobscheduler/service/java/com/android/server/job/controllers/Package.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2021 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.job.controllers;
+
+import java.util.Objects;
+
+/** Wrapper class to represent a userId-pkgName combo. */
+final class Package {
+    public final String packageName;
+    public final int userId;
+
+    Package(int userId, String packageName) {
+        this.userId = userId;
+        this.packageName = packageName;
+    }
+
+    @Override
+    public String toString() {
+        return packageToString(userId, packageName);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof Package)) {
+            return false;
+        }
+        Package other = (Package) obj;
+        return userId == other.userId && Objects.equals(packageName, other.packageName);
+    }
+
+    @Override
+    public int hashCode() {
+        return packageName.hashCode() + userId;
+    }
+
+    /**
+     * Standardize the output of userId-packageName combo.
+     */
+    static String packageToString(int userId, String packageName) {
+        return "<" + userId + ">" + packageName;
+    }
+}
diff --git a/apex/jobscheduler/service/java/com/android/server/job/controllers/PrefetchController.java b/apex/jobscheduler/service/java/com/android/server/job/controllers/PrefetchController.java
index 725092c328e5..6232dfb12822 100644
--- a/apex/jobscheduler/service/java/com/android/server/job/controllers/PrefetchController.java
+++ b/apex/jobscheduler/service/java/com/android/server/job/controllers/PrefetchController.java
@@ -20,9 +20,13 @@ import static android.text.format.DateUtils.HOUR_IN_MILLIS;
 
 import static com.android.server.job.JobSchedulerService.sElapsedRealtimeClock;
 import static com.android.server.job.JobSchedulerService.sSystemClock;
+import static com.android.server.job.controllers.Package.packageToString;
 
 import android.annotation.CurrentTimeMillisLong;
+import android.annotation.ElapsedRealtimeLong;
 import android.annotation.NonNull;
+import android.content.Context;
+import android.os.Looper;
 import android.os.UserHandle;
 import android.provider.DeviceConfig;
 import android.util.ArraySet;
@@ -36,6 +40,7 @@ import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.server.JobSchedulerBackgroundThread;
 import com.android.server.job.JobSchedulerService;
+import com.android.server.utils.AlarmQueue;
 
 import java.util.function.Predicate;
 
@@ -57,6 +62,7 @@ public class PrefetchController extends StateController {
      */
     @GuardedBy("mLock")
     private final SparseArrayMap<String, Long> mEstimatedLaunchTimes = new SparseArrayMap<>();
+    private final ThresholdAlarmListener mThresholdAlarmListener;
 
     /**
      * The cutoff point to decide if a prefetch job is worth running or not. If the app is expected
@@ -69,6 +75,8 @@ public class PrefetchController extends StateController {
     public PrefetchController(JobSchedulerService service) {
         super(service);
         mPcConstants = new PcConstants();
+        mThresholdAlarmListener = new ThresholdAlarmListener(
+                mContext, JobSchedulerBackgroundThread.get().getLooper());
     }
 
     @Override
@@ -82,9 +90,13 @@ public class PrefetchController extends StateController {
                 jobs = new ArraySet<>();
                 mTrackedJobs.add(userId, pkgName, jobs);
             }
-            jobs.add(jobStatus);
-            updateConstraintLocked(jobStatus,
-                    sSystemClock.millis(), sElapsedRealtimeClock.millis());
+            final long now = sSystemClock.millis();
+            final long nowElapsed = sElapsedRealtimeClock.millis();
+            if (jobs.add(jobStatus) && jobs.size() == 1
+                    && !willBeLaunchedSoonLocked(userId, pkgName, now)) {
+                updateThresholdAlarmLocked(userId, pkgName, now, nowElapsed);
+            }
+            updateConstraintLocked(jobStatus, now, nowElapsed);
         }
     }
 
@@ -92,10 +104,11 @@ public class PrefetchController extends StateController {
     @GuardedBy("mLock")
     public void maybeStopTrackingJobLocked(JobStatus jobStatus, JobStatus incomingJob,
             boolean forUpdate) {
-        final ArraySet<JobStatus> jobs = mTrackedJobs.get(jobStatus.getSourceUserId(),
-                jobStatus.getSourcePackageName());
-        if (jobs != null) {
-            jobs.remove(jobStatus);
+        final int userId = jobStatus.getSourceUserId();
+        final String pkgName = jobStatus.getSourcePackageName();
+        final ArraySet<JobStatus> jobs = mTrackedJobs.get(userId, pkgName);
+        if (jobs != null && jobs.remove(jobStatus) && jobs.size() == 0) {
+            mThresholdAlarmListener.removeAlarmForKey(new Package(userId, pkgName));
         }
     }
 
@@ -109,6 +122,7 @@ public class PrefetchController extends StateController {
         final int userId = UserHandle.getUserId(uid);
         mTrackedJobs.delete(userId, packageName);
         mEstimatedLaunchTimes.delete(userId, packageName);
+        mThresholdAlarmListener.removeAlarmForKey(new Package(userId, packageName));
     }
 
     @Override
@@ -116,6 +130,7 @@ public class PrefetchController extends StateController {
     public void onUserRemovedLocked(int userId) {
         mTrackedJobs.delete(userId);
         mEstimatedLaunchTimes.delete(userId);
+        mThresholdAlarmListener.removeAlarmsForUserId(userId);
     }
 
     /** Return the app's next estimated launch time. */
@@ -124,8 +139,14 @@ public class PrefetchController extends StateController {
     public long getNextEstimatedLaunchTimeLocked(@NonNull JobStatus jobStatus) {
         final int userId = jobStatus.getSourceUserId();
         final String pkgName = jobStatus.getSourcePackageName();
+        return getNextEstimatedLaunchTimeLocked(userId, pkgName, sSystemClock.millis());
+    }
+
+    @GuardedBy("mLock")
+    @CurrentTimeMillisLong
+    private long getNextEstimatedLaunchTimeLocked(int userId, @NonNull String pkgName,
+            @CurrentTimeMillisLong long now) {
         Long nextEstimatedLaunchTime = mEstimatedLaunchTimes.get(userId, pkgName);
-        final long now = sSystemClock.millis();
         if (nextEstimatedLaunchTime == null || nextEstimatedLaunchTime < now) {
             // TODO(194532703): get estimated time from UsageStats
             nextEstimatedLaunchTime = now + 2 * HOUR_IN_MILLIS;
@@ -135,8 +156,8 @@ public class PrefetchController extends StateController {
     }
 
     @GuardedBy("mLock")
-    private boolean maybeUpdateConstraintForPkgLocked(long now, long nowElapsed, int userId,
-            String pkgName) {
+    private boolean maybeUpdateConstraintForPkgLocked(@CurrentTimeMillisLong long now,
+            @ElapsedRealtimeLong long nowElapsed, int userId, String pkgName) {
         final ArraySet<JobStatus> jobs = mTrackedJobs.get(userId, pkgName);
         if (jobs == null) {
             return false;
@@ -150,10 +171,43 @@ public class PrefetchController extends StateController {
     }
 
     @GuardedBy("mLock")
-    private boolean updateConstraintLocked(@NonNull JobStatus jobStatus, long now,
-            long nowElapsed) {
+    private boolean updateConstraintLocked(@NonNull JobStatus jobStatus,
+            @CurrentTimeMillisLong long now, @ElapsedRealtimeLong long nowElapsed) {
         return jobStatus.setPrefetchConstraintSatisfied(nowElapsed,
-                getNextEstimatedLaunchTimeLocked(jobStatus) <= now + mLaunchTimeThresholdMs);
+                willBeLaunchedSoonLocked(
+                        jobStatus.getSourceUserId(), jobStatus.getSourcePackageName(), now));
+    }
+
+    @GuardedBy("mLock")
+    private void updateThresholdAlarmLocked(int userId, @NonNull String pkgName,
+            @CurrentTimeMillisLong long now, @ElapsedRealtimeLong long nowElapsed) {
+        final ArraySet<JobStatus> jobs = mTrackedJobs.get(userId, pkgName);
+        if (jobs == null || jobs.size() == 0) {
+            mThresholdAlarmListener.removeAlarmForKey(new Package(userId, pkgName));
+            return;
+        }
+
+        final long nextEstimatedLaunchTime = getNextEstimatedLaunchTimeLocked(userId, pkgName, now);
+        if (nextEstimatedLaunchTime - now > mLaunchTimeThresholdMs) {
+            // Set alarm to be notified when this crosses the threshold.
+            final long timeToCrossThresholdMs =
+                    nextEstimatedLaunchTime - (now + mLaunchTimeThresholdMs);
+            mThresholdAlarmListener.addAlarm(new Package(userId, pkgName),
+                    nowElapsed + timeToCrossThresholdMs);
+        } else {
+            mThresholdAlarmListener.removeAlarmForKey(new Package(userId, pkgName));
+        }
+    }
+
+    /**
+     * Returns true if the app is expected to be launched soon, where "soon" is within the next
+     * {@link #mLaunchTimeThresholdMs} time.
+     */
+    @GuardedBy("mLock")
+    private boolean willBeLaunchedSoonLocked(int userId, @NonNull String pkgName,
+            @CurrentTimeMillisLong long now) {
+        return getNextEstimatedLaunchTimeLocked(userId, pkgName, now)
+                <= now + mLaunchTimeThresholdMs;
     }
 
     @Override
@@ -186,6 +240,9 @@ public class PrefetchController extends StateController {
                                     now, nowElapsed, userId, packageName)) {
                                 changedJobs.addAll(mTrackedJobs.valueAt(u, p));
                             }
+                            if (!willBeLaunchedSoonLocked(userId, packageName, now)) {
+                                updateThresholdAlarmLocked(userId, packageName, now, nowElapsed);
+                            }
                         }
                     }
                 }
@@ -196,6 +253,42 @@ public class PrefetchController extends StateController {
         }
     }
 
+    /** Track when apps will cross the "will run soon" threshold. */
+    private class ThresholdAlarmListener extends AlarmQueue<Package> {
+        private ThresholdAlarmListener(Context context, Looper looper) {
+            super(context, looper, "*job.prefetch*", "Prefetch threshold", false,
+                    PcConstants.DEFAULT_LAUNCH_TIME_THRESHOLD_MS / 10);
+        }
+
+        @Override
+        protected boolean isForUser(@NonNull Package key, int userId) {
+            return key.userId == userId;
+        }
+
+        @Override
+        protected void processExpiredAlarms(@NonNull ArraySet<Package> expired) {
+            final ArraySet<JobStatus> changedJobs = new ArraySet<>();
+            synchronized (mLock) {
+                final long now = sSystemClock.millis();
+                final long nowElapsed = sElapsedRealtimeClock.millis();
+                for (int i = 0; i < expired.size(); ++i) {
+                    Package p = expired.valueAt(i);
+                    if (!willBeLaunchedSoonLocked(p.userId, p.packageName, now)) {
+                        Slog.e(TAG, "Alarm expired for "
+                                + packageToString(p.userId, p.packageName) + " at the wrong time");
+                        updateThresholdAlarmLocked(p.userId, p.packageName, now, nowElapsed);
+                    } else if (maybeUpdateConstraintForPkgLocked(
+                            now, nowElapsed, p.userId, p.packageName)) {
+                        changedJobs.addAll(mTrackedJobs.get(p.userId, p.packageName));
+                    }
+                }
+            }
+            if (changedJobs.size() > 0) {
+                mStateChangedListener.onControllerStateChanged(changedJobs);
+            }
+        }
+    }
+
     @VisibleForTesting
     class PcConstants {
         private boolean mShouldReevaluateConstraints = false;
@@ -225,6 +318,9 @@ public class PrefetchController extends StateController {
                     if (mLaunchTimeThresholdMs != newLaunchTimeThresholdMs) {
                         mLaunchTimeThresholdMs = newLaunchTimeThresholdMs;
                         mShouldReevaluateConstraints = true;
+                        // Give a leeway of 10% of the launch time threshold between alarms.
+                        mThresholdAlarmListener.setMinTimeBetweenAlarmsMs(
+                                mLaunchTimeThresholdMs / 10);
                     }
                     break;
             }
@@ -294,6 +390,9 @@ public class PrefetchController extends StateController {
                 pw.println();
             }
         });
+
+        pw.println();
+        mThresholdAlarmListener.dump(pw);
     }
 
     @Override
diff --git a/apex/jobscheduler/service/java/com/android/server/job/controllers/QuotaController.java b/apex/jobscheduler/service/java/com/android/server/job/controllers/QuotaController.java
index 1016294fba2e..31da526bead9 100644
--- a/apex/jobscheduler/service/java/com/android/server/job/controllers/QuotaController.java
+++ b/apex/jobscheduler/service/java/com/android/server/job/controllers/QuotaController.java
@@ -27,6 +27,7 @@ import static com.android.server.job.JobSchedulerService.RARE_INDEX;
 import static com.android.server.job.JobSchedulerService.RESTRICTED_INDEX;
 import static com.android.server.job.JobSchedulerService.WORKING_INDEX;
 import static com.android.server.job.JobSchedulerService.sElapsedRealtimeClock;
+import static com.android.server.job.controllers.Package.packageToString;
 
 import android.Manifest;
 import android.annotation.NonNull;
@@ -79,7 +80,6 @@ import com.android.server.utils.AlarmQueue;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
@@ -123,52 +123,6 @@ public final class QuotaController extends StateController {
             PackageManager.MATCH_DIRECT_BOOT_AWARE | PackageManager.MATCH_DIRECT_BOOT_UNAWARE
                     | PackageManager.GET_PERMISSIONS | PackageManager.MATCH_KNOWN_PACKAGES;
 
-    /**
-     * Standardize the output of userId-packageName combo.
-     */
-    private static String string(int userId, String packageName) {
-        return "<" + userId + ">" + packageName;
-    }
-
-    private static final class Package {
-        public final String packageName;
-        public final int userId;
-
-        Package(int userId, String packageName) {
-            this.userId = userId;
-            this.packageName = packageName;
-        }
-
-        @Override
-        public String toString() {
-            return string(userId, packageName);
-        }
-
-        public void dumpDebug(ProtoOutputStream proto, long fieldId) {
-            final long token = proto.start(fieldId);
-
-            proto.write(StateControllerProto.QuotaController.Package.USER_ID, userId);
-            proto.write(StateControllerProto.QuotaController.Package.NAME, packageName);
-
-            proto.end(token);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj instanceof Package) {
-                Package other = (Package) obj;
-                return userId == other.userId && Objects.equals(packageName, other.packageName);
-            } else {
-                return false;
-            }
-        }
-
-        @Override
-        public int hashCode() {
-            return packageName.hashCode() + userId;
-        }
-    }
-
     private static int hashLong(long val) {
         return (int) (val ^ (val >>> 32));
     }
@@ -1741,7 +1695,6 @@ public final class QuotaController extends StateController {
             return;
         }
 
-        final String pkgString = string(userId, packageName);
         ExecutionStats stats = getExecutionStatsLocked(userId, packageName, standbyBucket);
         final boolean isUnderJobCountQuota = isUnderJobCountQuotaLocked(stats, standbyBucket);
         final boolean isUnderTimingSessionCountQuota = isUnderSessionCountQuotaLocked(stats,
@@ -1755,7 +1708,8 @@ public final class QuotaController extends StateController {
         if (inRegularQuota && remainingEJQuota > 0) {
             // Already in quota. Why was this method called?
             if (DEBUG) {
-                Slog.e(TAG, "maybeScheduleStartAlarmLocked called for " + pkgString
+                Slog.e(TAG, "maybeScheduleStartAlarmLocked called for "
+                        + packageToString(userId, packageName)
                         + " even though it already has "
                         + getRemainingExecutionTimeLocked(userId, packageName, standbyBucket)
                         + "ms in its quota.");
@@ -1811,8 +1765,8 @@ public final class QuotaController extends StateController {
                 // In some strange cases, an app may end be in the NEVER bucket but could have run
                 // some regular jobs. This results in no EJ timing sessions and QC having a bad
                 // time.
-                Slog.wtf(TAG,
-                        string(userId, packageName) + " has 0 EJ quota without running anything");
+                Slog.wtf(TAG, packageToString(userId, packageName)
+                        + " has 0 EJ quota without running anything");
                 return;
             }
         }
@@ -2272,7 +2226,6 @@ public final class QuotaController extends StateController {
         public void dump(ProtoOutputStream proto, long fieldId, Predicate<JobStatus> predicate) {
             final long token = proto.start(fieldId);
 
-            mPkg.dumpDebug(proto, StateControllerProto.QuotaController.Timer.PKG);
             proto.write(StateControllerProto.QuotaController.Timer.IS_ACTIVE, isActive());
             proto.write(StateControllerProto.QuotaController.Timer.START_TIME_ELAPSED,
                     mStartTimeElapsed);
@@ -2381,7 +2334,6 @@ public final class QuotaController extends StateController {
         public void dump(ProtoOutputStream proto, long fieldId) {
             final long token = proto.start(fieldId);
 
-            mPkg.dumpDebug(proto, StateControllerProto.QuotaController.TopAppTimer.PKG);
             proto.write(StateControllerProto.QuotaController.TopAppTimer.IS_ACTIVE, isActive());
             proto.write(StateControllerProto.QuotaController.TopAppTimer.START_TIME_ELAPSED,
                     mStartTimeElapsed);
@@ -2413,7 +2365,7 @@ public final class QuotaController extends StateController {
     void updateStandbyBucket(
             final int userId, final @NonNull String packageName, final int bucketIndex) {
         if (DEBUG) {
-            Slog.i(TAG, "Moving pkg " + string(userId, packageName)
+            Slog.i(TAG, "Moving pkg " + packageToString(userId, packageName)
                     + " to bucketIndex " + bucketIndex);
         }
         List<JobStatus> restrictedChanges = new ArrayList<>();
@@ -2641,7 +2593,7 @@ public final class QuotaController extends StateController {
                         String packageName = (String) msg.obj;
                         int userId = msg.arg1;
                         if (DEBUG) {
-                            Slog.d(TAG, "Checking pkg " + string(userId, packageName));
+                            Slog.d(TAG, "Checking pkg " + packageToString(userId, packageName));
                         }
                         if (maybeUpdateConstraintForPkgLocked(sElapsedRealtimeClock.millis(),
                                 userId, packageName)) {
@@ -2722,7 +2674,7 @@ public final class QuotaController extends StateController {
                         final String pkgName = event.getPackageName();
                         if (DEBUG) {
                             Slog.d(TAG, "Processing event " + event.getEventType()
-                                    + " for " + string(userId, pkgName));
+                                    + " for " + packageToString(userId, pkgName));
                         }
                         switch (event.getEventType()) {
                             case UsageEvents.Event.ACTIVITY_RESUMED:
@@ -4119,7 +4071,7 @@ public final class QuotaController extends StateController {
                 final String pkgName = mExecutionStatsCache.keyAt(u, p);
                 ExecutionStats[] stats = mExecutionStatsCache.valueAt(u, p);
 
-                pw.println(string(userId, pkgName));
+                pw.println(packageToString(userId, pkgName));
                 pw.increaseIndent();
                 for (int i = 0; i < stats.length; ++i) {
                     ExecutionStats executionStats = stats[i];
@@ -4143,7 +4095,7 @@ public final class QuotaController extends StateController {
                 final String pkgName = mEJStats.keyAt(u, p);
                 ShrinkableDebits debits = mEJStats.valueAt(u, p);
 
-                pw.print(string(userId, pkgName));
+                pw.print(packageToString(userId, pkgName));
                 pw.print(": ");
                 debits.dumpLocked(pw);
             }