Attribute alarm broadcast wakelocks to the sender

Wakelock usage for the purpose of sending an alarm broadcast is now
attributed to the application which posted the alarm, not to the OS.

Bug 5911317

Change-Id: I8cb79c3bd5db467388716ab68285f4ab0bfe468b

4 files changed, 68 insertions, 3 deletions

diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index 000abc5f975a..a3fdf3e81a34 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -867,6 +867,16 @@ public abstract class ActivityManagerNative extends Binder implements IActivityM
             return true;
         }
 
+        case GET_UID_FOR_INTENT_SENDER_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IIntentSender r = IIntentSender.Stub.asInterface(
+                data.readStrongBinder());
+            int res = getUidForIntentSender(r);
+            reply.writeNoException();
+            reply.writeInt(res);
+            return true;
+        }
+
         case SET_PROCESS_LIMIT_TRANSACTION: {
             data.enforceInterface(IActivityManager.descriptor);
             int max = data.readInt();
@@ -2714,6 +2724,18 @@ class ActivityManagerProxy implements IActivityManager
         reply.recycle();
         return res;
     }
+    public int getUidForIntentSender(IIntentSender sender) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(sender.asBinder());
+        mRemote.transact(GET_UID_FOR_INTENT_SENDER_TRANSACTION, data, reply, 0);
+        reply.readException();
+        int res = reply.readInt();
+        data.recycle();
+        reply.recycle();
+        return res;
+    }
     public void setProcessLimit(int max) throws RemoteException
     {
         Parcel data = Parcel.obtain();
diff --git a/core/java/android/app/IActivityManager.java b/core/java/android/app/IActivityManager.java
index 0f287c113e04..c71b186189bb 100644
--- a/core/java/android/app/IActivityManager.java
+++ b/core/java/android/app/IActivityManager.java
@@ -175,6 +175,7 @@ public interface IActivityManager extends IInterface {
     public boolean clearApplicationUserData(final String packageName,
             final IPackageDataObserver observer, int userId) throws RemoteException;
     public String getPackageForIntentSender(IIntentSender sender) throws RemoteException;
+    public int getUidForIntentSender(IIntentSender sender) throws RemoteException;
     
     public void setProcessLimit(int max) throws RemoteException;
     public int getProcessLimit() throws RemoteException;
@@ -531,6 +532,7 @@ public interface IActivityManager extends IInterface {
     int START_BACKUP_AGENT_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+89;
     int BACKUP_AGENT_CREATED_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+90;
     int UNBIND_BACKUP_AGENT_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+91;
+    int GET_UID_FOR_INTENT_SENDER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+92;
 
 
     int START_ACTIVITY_IN_PACKAGE_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+94;
diff --git a/services/java/com/android/server/AlarmManagerService.java b/services/java/com/android/server/AlarmManagerService.java
index 057440572384..32ac8e1506cd 100644
--- a/services/java/com/android/server/AlarmManagerService.java
+++ b/services/java/com/android/server/AlarmManagerService.java
@@ -34,9 +34,9 @@ import android.os.Message;
 import android.os.PowerManager;
 import android.os.SystemClock;
 import android.os.SystemProperties;
+import android.os.WorkSource;
 import android.text.TextUtils;
 import android.text.format.Time;
-import android.util.EventLog;
 import android.util.Slog;
 import android.util.TimeUtils;
 
@@ -50,6 +50,7 @@ import java.util.Comparator;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.Map;
 import java.util.TimeZone;
 
@@ -89,6 +90,7 @@ class AlarmManagerService extends IAlarmManager.Stub {
     private int mDescriptor;
     private int mBroadcastRefCount = 0;
     private PowerManager.WakeLock mWakeLock;
+    private LinkedList<PendingIntent> mInFlight = new LinkedList<PendingIntent>();
     private final AlarmThread mWaitThread = new AlarmThread();
     private final AlarmHandler mHandler = new AlarmHandler();
     private ClockReceiver mClockReceiver;
@@ -668,10 +670,12 @@ class AlarmManagerService extends IAlarmManager.Stub {
                                             Intent.EXTRA_ALARM_COUNT, alarm.count),
                                     mResultReceiver, mHandler);
                             
-                            // we have an active broadcast so stay awake. 
+                            // we have an active broadcast so stay awake.
                             if (mBroadcastRefCount == 0) {
+                                setWakelockWorkSource(alarm.operation);
                                 mWakeLock.acquire();
                             }
+                            mInFlight.add(alarm.operation);
                             mBroadcastRefCount++;
                             
                             BroadcastStats bs = getStatsLocked(alarm.operation);
@@ -700,7 +704,22 @@ class AlarmManagerService extends IAlarmManager.Stub {
             }
         }
     }
-    
+
+    void setWakelockWorkSource(PendingIntent pi) {
+        try {
+            final int uid = ActivityManagerNative.getDefault()
+                    .getUidForIntentSender(pi.getTarget());
+            if (uid >= 0) {
+                mWakeLock.setWorkSource(new WorkSource(uid));
+                return;
+            }
+        } catch (Exception e) {
+        }
+
+        // Something went wrong; fall back to attributing the lock to the OS
+        mWakeLock.setWorkSource(null);
+    }
+
     private class AlarmHandler extends Handler {
         public static final int ALARM_EVENT = 1;
         public static final int MINUTE_CHANGE_EVENT = 2;
@@ -876,9 +895,20 @@ class AlarmManagerService extends IAlarmManager.Stub {
                         fs.count++;
                     }
                 }
+                mInFlight.removeFirst();
                 mBroadcastRefCount--;
                 if (mBroadcastRefCount == 0) {
                     mWakeLock.release();
+                } else {
+                    // the next of our alarms is now in flight.  reattribute the wakelock.
+                    final PendingIntent nowInFlight = mInFlight.peekFirst();
+                    if (nowInFlight != null) {
+                        setWakelockWorkSource(nowInFlight);
+                    } else {
+                        // should never happen
+                        Slog.e(TAG, "Alarm wakelock still held but sent queue empty");
+                        mWakeLock.setWorkSource(null);
+                    }
                 }
             }
         }
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 33250b8b6c15..a95382434f81 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -4444,6 +4444,17 @@ public final class ActivityManagerService extends ActivityManagerNative
         return null;
     }
 
+    public int getUidForIntentSender(IIntentSender sender) {
+        if (sender instanceof PendingIntentRecord) {
+            try {
+                PendingIntentRecord res = (PendingIntentRecord)sender;
+                return res.uid;
+            } catch (ClassCastException e) {
+            }
+        }
+        return -1;
+    }
+
     public boolean isIntentSenderTargetedToPackage(IIntentSender pendingResult) {
         if (!(pendingResult instanceof PendingIntentRecord)) {
             return false;