Merge "Modify usagestats event processing thread" into main
diff --git a/core/java/android/app/usage/flags.aconfig b/core/java/android/app/usage/flags.aconfig
index f401a76..4f1c65b 100644
--- a/core/java/android/app/usage/flags.aconfig
+++ b/core/java/android/app/usage/flags.aconfig
@@ -13,3 +13,11 @@
     description: "Feature flag for the new REPORT_USAGE_STATS permission."
     bug: "296056771"
 }
+
+flag {
+    name: "use_dedicated_handler_thread"
+    namespace: "backstage_power"
+    description: "Flag to use a dedicated thread for usage event process"
+    is_fixed_read_only: true
+    bug: "299336442"
+}
diff --git a/services/usage/java/com/android/server/usage/UsageStatsHandlerThread.java b/services/usage/java/com/android/server/usage/UsageStatsHandlerThread.java
new file mode 100644
index 0000000..31418d6
--- /dev/null
+++ b/services/usage/java/com/android/server/usage/UsageStatsHandlerThread.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2023 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.usage;
+
+import android.os.Looper;
+import android.os.Trace;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.server.ServiceThread;
+
+/**
+ * Shared singleton default priority thread for usage stats message handling.
+ */
+public class UsageStatsHandlerThread extends ServiceThread {
+    private static final long SLOW_DISPATCH_THRESHOLD_MS = 10_000;
+    private static final long SLOW_DELIVERY_THRESHOLD_MS = 30_000;
+
+    private static final Object sLock = new Object();
+
+    @GuardedBy("sLock")
+    private static UsageStatsHandlerThread sInstance;
+
+    private UsageStatsHandlerThread() {
+        super("android.usagestats", android.os.Process.THREAD_PRIORITY_DEFAULT,
+                /* allowIo= */ true);
+    }
+
+    @GuardedBy("sLock")
+    private static void ensureThreadLocked() {
+        if (sInstance != null) {
+            return;
+        }
+
+        sInstance = new UsageStatsHandlerThread();
+        sInstance.start();
+        final Looper looper = sInstance.getLooper();
+        looper.setTraceTag(Trace.TRACE_TAG_SYSTEM_SERVER);
+        looper.setSlowLogThresholdMs(
+                SLOW_DISPATCH_THRESHOLD_MS, SLOW_DELIVERY_THRESHOLD_MS);
+    }
+
+    /**
+     * Obtain a singleton instance of the UsageStatsHandlerThread.
+     */
+    public static UsageStatsHandlerThread get() {
+        synchronized (sLock) {
+            ensureThreadLocked();
+            return sInstance;
+        }
+    }
+}
diff --git a/services/usage/java/com/android/server/usage/UsageStatsService.java b/services/usage/java/com/android/server/usage/UsageStatsService.java
index 55b5d11..e413663 100644
--- a/services/usage/java/com/android/server/usage/UsageStatsService.java
+++ b/services/usage/java/com/android/server/usage/UsageStatsService.java
@@ -202,6 +202,7 @@
     static final int MSG_HANDLE_LAUNCH_TIME_ON_USER_UNLOCK = 8;
     static final int MSG_NOTIFY_ESTIMATED_LAUNCH_TIMES_CHANGED = 9;
     static final int MSG_UID_REMOVED = 10;
+    static final int MSG_USER_STARTED = 11;
 
     private final Object mLock = new Object();
     private Handler mHandler;
@@ -334,7 +335,7 @@
         mUserManager = (UserManager) getContext().getSystemService(Context.USER_SERVICE);
         mPackageManager = getContext().getPackageManager();
         mPackageManagerInternal = LocalServices.getService(PackageManagerInternal.class);
-        mHandler = new H(BackgroundThread.get().getLooper());
+        mHandler = getUsageEventProcessingHandler();
         mIoHandler = new Handler(IoThread.get().getLooper(), mIoHandlerCallback);
 
         mAppStandby = mInjector.getAppStandbyController(getContext());
@@ -380,10 +381,12 @@
 
         IntentFilter filter = new IntentFilter(Intent.ACTION_USER_REMOVED);
         filter.addAction(Intent.ACTION_USER_STARTED);
-        getContext().registerReceiverAsUser(new UserActionsReceiver(), UserHandle.ALL,
-                filter, null, /* Handler scheduler */ null);
+        getContext().registerReceiverAsUser(new UserActionsReceiver(), UserHandle.ALL, filter,
+                null, /* scheduler= */ Flags.useDedicatedHandlerThread() ? mHandler : null);
+
         getContext().registerReceiverAsUser(new UidRemovedReceiver(), UserHandle.ALL,
-                new IntentFilter(ACTION_UID_REMOVED), null, /* Handler scheduler */ null);
+                new IntentFilter(ACTION_UID_REMOVED), null,
+                /* scheduler= */ Flags.useDedicatedHandlerThread() ? mHandler : null);
 
         mRealTimeSnapshot = SystemClock.elapsedRealtime();
         mSystemTimeSnapshot = System.currentTimeMillis();
@@ -471,6 +474,14 @@
         }
     }
 
+    private Handler getUsageEventProcessingHandler() {
+        if (Flags.useDedicatedHandlerThread()) {
+            return new H(UsageStatsHandlerThread.get().getLooper());
+        } else {
+            return new H(BackgroundThread.get().getLooper());
+        }
+    }
+
     private void onUserUnlocked(int userId) {
         // fetch the installed packages outside the lock so it doesn't block package manager.
         final HashMap<String, Long> installedPackages = getInstalledPackages(userId);
@@ -618,7 +629,7 @@
                 }
             } else if (Intent.ACTION_USER_STARTED.equals(action)) {
                 if (userId >= 0) {
-                    mAppStandby.postCheckIdleStates(userId);
+                    mHandler.obtainMessage(MSG_USER_STARTED, userId, 0).sendToTarget();
                 }
             }
         }
@@ -1554,8 +1565,7 @@
         synchronized (mLaunchTimeAlarmQueues) {
             LaunchTimeAlarmQueue alarmQueue = mLaunchTimeAlarmQueues.get(userId);
             if (alarmQueue == null) {
-                alarmQueue = new LaunchTimeAlarmQueue(
-                    userId, getContext(), BackgroundThread.get().getLooper());
+                alarmQueue = new LaunchTimeAlarmQueue(userId, getContext(), mHandler.getLooper());
                 mLaunchTimeAlarmQueues.put(userId, alarmQueue);
             }
 
@@ -2040,6 +2050,9 @@
                 case MSG_UID_REMOVED:
                     mResponseStatsTracker.onUidRemoved(msg.arg1);
                     break;
+                case MSG_USER_STARTED:
+                    mAppStandby.postCheckIdleStates(msg.arg1);
+                    break;
                 case MSG_PACKAGE_REMOVED:
                     onPackageRemoved(msg.arg1, (String) msg.obj);
                     break;