From 9fa19313dd9210902a3085b5a3a52bd8fd29686d Mon Sep 17 00:00:00 2001
From: Christopher Tate <ctate@google.com>
Date: Thu, 11 Jul 2013 14:43:13 -0700
Subject: [PATCH] Batch alarms to reduce device wakeups

The default Alarm Manager behavior for KLP+ apps will be to aggressively
coalesce alarms, trading exact timeliness of delivery for minimizing the
number of alarm-delivery points, especially wakeup points.

There is new API in AlarmManager, setExact() and setExactRepeating(),
for use by apps that absolutely *must* get their alarms at a specific
point in time.

Bug 9532215

Change-Id: I40b4eea90220211cc958172d2629664b921ff051
---
 .../server/net/NetworkStatsService.java       | 26 ++++++++-----------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/services/java/com/android/server/net/NetworkStatsService.java b/services/java/com/android/server/net/NetworkStatsService.java
index 5074409694..05eeb36195 100644
--- a/services/java/com/android/server/net/NetworkStatsService.java
+++ b/services/java/com/android/server/net/NetworkStatsService.java
@@ -154,7 +154,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
 
     private final Context mContext;
     private final INetworkManagementService mNetworkManager;
-    private final IAlarmManager mAlarmManager;
+    private final AlarmManager mAlarmManager;
     private final TrustedTime mTime;
     private final TelephonyManager mTeleManager;
     private final NetworkStatsSettings mSettings;
@@ -261,10 +261,10 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
             NetworkStatsSettings settings) {
         mContext = checkNotNull(context, "missing Context");
         mNetworkManager = checkNotNull(networkManager, "missing INetworkManagementService");
-        mAlarmManager = checkNotNull(alarmManager, "missing IAlarmManager");
         mTime = checkNotNull(time, "missing TrustedTime");
         mTeleManager = checkNotNull(TelephonyManager.getDefault(), "missing TelephonyManager");
         mSettings = checkNotNull(settings, "missing NetworkStatsSettings");
+        mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
 
         final PowerManager powerManager = (PowerManager) context.getSystemService(
                 Context.POWER_SERVICE);
@@ -420,20 +420,16 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
      * reschedule based on current {@link NetworkStatsSettings#getPollInterval()}.
      */
     private void registerPollAlarmLocked() {
-        try {
-            if (mPollIntent != null) {
-                mAlarmManager.remove(mPollIntent);
-            }
-
-            mPollIntent = PendingIntent.getBroadcast(
-                    mContext, 0, new Intent(ACTION_NETWORK_STATS_POLL), 0);
-
-            final long currentRealtime = SystemClock.elapsedRealtime();
-            mAlarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME, currentRealtime,
-                    mSettings.getPollInterval(), mPollIntent);
-        } catch (RemoteException e) {
-            // ignored; service lives in system_server
+        if (mPollIntent != null) {
+            mAlarmManager.cancel(mPollIntent);
         }
+
+        mPollIntent = PendingIntent.getBroadcast(
+                mContext, 0, new Intent(ACTION_NETWORK_STATS_POLL), 0);
+
+        final long currentRealtime = SystemClock.elapsedRealtime();
+        mAlarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME, currentRealtime,
+                mSettings.getPollInterval(), mPollIntent);
     }
 
     /**