DO NOT MERGE ANYWHERE: Hold a wake lock while DeviceIdleController

is going idle.

The inputs to DeviceIdleController (alarm manager, sensors)
hold wake locks while they call it.  But then the real work
happens in a handler which is outside of the wakelock, so
listeners don't get a chance to run right away, which in
the case of NetworkPolicyManager means the device is in a
higher power state than it should be.

It's not clear that this will 100% fix the bug, because
NetworkPolicyManagerService also has its own internal
Handler, and isn't holding its own wakelock for this,
but this change allows NPMS to be fixed if it really
needed to be.

Bug: 31900521
Change-Id: I706045aa189147824c9214c57abc13993aee9a5b

1 files changed, 21 insertions, 5 deletions

diff --git a/services/core/java/com/android/server/DeviceIdleController.java b/services/core/java/com/android/server/DeviceIdleController.java
index a057ac9dea53..9c04e6159cc5 100644
--- a/services/core/java/com/android/server/DeviceIdleController.java
+++ b/services/core/java/com/android/server/DeviceIdleController.java
@@ -110,6 +110,7 @@ public class DeviceIdleController extends SystemService
     private AlarmManager mAlarmManager;
     private IBatteryStats mBatteryStats;
     private PowerManagerInternal mLocalPowerManager;
+    private PowerManager mPowerManager;
     private INetworkPolicyManager mNetworkPolicyManager;
     private DisplayManager mDisplayManager;
     private SensorManager mSensorManager;
@@ -168,6 +169,11 @@ public class DeviceIdleController extends SystemService
     private long mNextIdlePendingDelay;
     private long mNextIdleDelay;
 
+    /**
+     * Wakelock held when going idle so hardware (especially NetworkPolicyManager) can shut down.
+     */
+    private PowerManager.WakeLock mGoingIdleWakelock;
+
     public final AtomicFile mConfigFile;
 
     /**
@@ -685,11 +691,11 @@ public class DeviceIdleController extends SystemService
         }
     }
 
-    static final int MSG_WRITE_CONFIG = 1;
-    static final int MSG_REPORT_IDLE_ON = 2;
-    static final int MSG_REPORT_IDLE_OFF = 3;
-    static final int MSG_REPORT_ACTIVE = 4;
-    static final int MSG_TEMP_APP_WHITELIST_TIMEOUT = 5;
+    private static final int MSG_WRITE_CONFIG = 1;
+    private static final int MSG_REPORT_IDLE_ON = 2;
+    private static final int MSG_REPORT_IDLE_OFF = 3;
+    private static final int MSG_REPORT_ACTIVE = 4;
+    private static final int MSG_TEMP_APP_WHITELIST_TIMEOUT = 5;
 
     final class MyHandler extends Handler {
         MyHandler(Looper looper) {
@@ -700,9 +706,11 @@ public class DeviceIdleController extends SystemService
             if (DEBUG) Slog.d(TAG, "handleMessage(" + msg.what + ")");
             switch (msg.what) {
                 case MSG_WRITE_CONFIG: {
+                    // Does not hold a wakelock. Just let this happen whenever.
                     handleWriteConfigFile();
                 } break;
                 case MSG_REPORT_IDLE_ON: {
+                    // mGoingIdleWakelock is held at this point
                     EventLogTags.writeDeviceIdleOnStart();
                     mLocalPowerManager.setDeviceIdleMode(true);
                     try {
@@ -712,6 +720,7 @@ public class DeviceIdleController extends SystemService
                     }
                     getContext().sendBroadcastAsUser(mIdleIntent, UserHandle.ALL);
                     EventLogTags.writeDeviceIdleOnComplete();
+                    mGoingIdleWakelock.release();
                 } break;
                 case MSG_REPORT_IDLE_OFF: {
                     EventLogTags.writeDeviceIdleOffStart("unknown");
@@ -725,6 +734,7 @@ public class DeviceIdleController extends SystemService
                     EventLogTags.writeDeviceIdleOffComplete();
                 } break;
                 case MSG_REPORT_ACTIVE: {
+                    // The device is awake at this point, so no wakelock necessary.
                     String activeReason = (String)msg.obj;
                     int activeUid = msg.arg1;
                     boolean needBroadcast = msg.arg2 != 0;
@@ -742,6 +752,7 @@ public class DeviceIdleController extends SystemService
                     EventLogTags.writeDeviceIdleOffComplete();
                 } break;
                 case MSG_TEMP_APP_WHITELIST_TIMEOUT: {
+                    // TODO: What is keeping the device awake at this point? Does it need to be?
                     int uid = msg.arg1;
                     checkTempAppWhitelistTimeout(uid);
                 } break;
@@ -931,6 +942,10 @@ public class DeviceIdleController extends SystemService
                 mAlarmManager = (AlarmManager) getContext().getSystemService(Context.ALARM_SERVICE);
                 mBatteryStats = BatteryStatsService.getService();
                 mLocalPowerManager = getLocalService(PowerManagerInternal.class);
+                mPowerManager = getContext().getSystemService(PowerManager.class);
+                mGoingIdleWakeLock = mPowerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
+                        "deviceidle_going_idle");
+                mGoingIdleWakeLock.setReferenceCounted(true);
                 mNetworkPolicyManager = INetworkPolicyManager.Stub.asInterface(
                         ServiceManager.getService(Context.NETWORK_POLICY_SERVICE));
                 mDisplayManager = (DisplayManager) getContext().getSystemService(
@@ -1396,6 +1411,7 @@ public class DeviceIdleController extends SystemService
                 mNextIdleDelay = Math.min(mNextIdleDelay, mConstants.MAX_IDLE_TIMEOUT);
                 mState = STATE_IDLE;
                 EventLogTags.writeDeviceIdle(mState, "step");
+                mGoingIdleWakelock.acquire();
                 mHandler.sendEmptyMessage(MSG_REPORT_IDLE_ON);
                 break;
             case STATE_IDLE: