Merge "Tune delivery and batching of alarms" into lmp-mr1-dev (8ec2dc00) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/AlarmManagerService.java

+63 −23

Original line number	Diff line number	Diff line
		@@ -61,6 +61,7 @@ import java.util.Date;
		import java.util.HashMap;
		import java.util.LinkedList;
		import java.util.Locale;
		import java.util.Random;
		import java.util.TimeZone;

		import static android.app.AlarmManager.RTC_WAKEUP;
		@@ -114,8 +115,12 @@ class AlarmManagerService extends SystemService {
		final Object mLock = new Object();

		long mNativeData;
		private long mNextWakeup;

		private final Random mFuzzer = new Random();
		private long mNextWakeupBatchStart; // nominal start of next wakeup's delivery window
		private long mNextWakeup; // actual scheduled next wakeup within that window
		private long mNextNonWakeup;

		int mBroadcastRefCount = 0;
		PowerManager.WakeLock mWakeLock;
		boolean mLastWakeLockUnimportantForLogging;
		@@ -367,14 +372,27 @@ class AlarmManagerService extends SystemService {

		static class BatchTimeOrder implements Comparator<Batch> {
		public int compare(Batch b1, Batch b2) {
		long when1 = b1.start;
		long when2 = b2.start;
		if (when1 - when2 > 0) {
		final long start1 = b1.start;
		final long start2 = b2.start;
		if (start1 > start2) {
		return 1;
		}
		if (when1 - when2 < 0) {
		if (start1 < start2) {
		return -1;
		}

		// Identical trigger times. As a secondary ordering, require that
		// the batch with the shorter allowable delivery window sorts first.
		final long interval1 = b1.end - b1.start;
		final long interval2 = b2.end - b2.start;
		if (interval1 > interval2) {
		return 1;
		}
		if (interval2 < interval1) {
		return -1;
		}

		// equal start + delivery window => they're identical
		return 0;
		}
		}
		@@ -597,7 +615,7 @@ class AlarmManagerService extends SystemService {
		@Override
		public void onStart() {
		mNativeData = init();
		mNextWakeup = mNextNonWakeup = 0;
		mNextWakeup = mNextWakeupBatchStart = mNextNonWakeup = 0;

		// We have to set current TimeZone info to kernel
		// because kernel doesn't keep this after reboot
		@@ -805,8 +823,9 @@ class AlarmManagerService extends SystemService {
		"AlarmManager.set");
		}

		// Exact alarms are standalone; inexact get batched together
		setImpl(type, triggerAtTime, windowLength, interval, operation,
		false, workSource, alarmClock);
		windowLength == AlarmManager.WINDOW_EXACT, workSource, alarmClock);
		}

		@Override
		@@ -877,7 +896,7 @@ class AlarmManagerService extends SystemService {

		pw.print("nowRTC="); pw.print(nowRTC);
		pw.print("="); pw.print(sdf.format(new Date(nowRTC)));
		pw.print(" nowELAPSED="); TimeUtils.formatDuration(nowELAPSED, pw);
		pw.print(" nowELAPSED="); pw.print(nowELAPSED);
		pw.println();
		if (!mInteractive) {
		pw.print("Time since non-interactive: ");
		@@ -1083,17 +1102,6 @@ class AlarmManagerService extends SystemService {
		return true;
		}

		private Batch findFirstWakeupBatchLocked() {
		final int N = mAlarmBatches.size();
		for (int i = 0; i < N; i++) {
		Batch b = mAlarmBatches.get(i);
		if (b.hasWakeups()) {
		return b;
		}
		}
		return null;
		}

		private AlarmManager.AlarmClockInfo getNextAlarmClockImpl(int userId) {
		synchronized (mLock) {
		return mNextAlarmClockForUser.get(userId);
		@@ -1228,16 +1236,48 @@ class AlarmManagerService extends SystemService {
		// prior to that which contains no wakeups, we schedule that as well.
		long nextNonWakeup = 0;
		if (mAlarmBatches.size() > 0) {
		final Batch firstWakeup = findFirstWakeupBatchLocked();
		// Find the first wakeup alarm and note the following batch as well. We'll be
		// choosing a fuzzed delivery time within the first's allowable interval but
		// ensuring that it does not encroach on the second's start time, to minimize
		// alarm reordering.
		Batch firstWakeup = null, nextAfterWakeup = null;
		final int N = mAlarmBatches.size();
		for (int i = 0; i < N; i++) {
		Batch b = mAlarmBatches.get(i);
		if (b.hasWakeups()) {
		firstWakeup = b;
		if (i < N-1) {
		nextAfterWakeup = mAlarmBatches.get(i+1);
		}
		break;
		}
		}

		// There's a subtlety here: we depend on the invariant that if two batches
		// exist with the same start time, the one with the shorter delivery window
		// is sorted before the other. This guarantees us that we need only look
		// at the first [relevant] batch in the queue in order to schedule an alarm
		// appropriately.
		final Batch firstBatch = mAlarmBatches.get(0);
		if (firstWakeup != null && mNextWakeup != firstWakeup.start) {
		mNextWakeup = firstWakeup.start;
		setLocked(ELAPSED_REALTIME_WAKEUP, firstWakeup.start);
		if (firstWakeup != null && mNextWakeupBatchStart != firstWakeup.start) {
		mNextWakeupBatchStart = mNextWakeup = firstWakeup.start;
		final long windowEnd = (nextAfterWakeup == null)
		? firstWakeup.end
		: Math.min(firstWakeup.end, nextAfterWakeup.start);
		final long interval = windowEnd - firstWakeup.start;
		// if the interval is over maxint we're into crazy land anyway, but
		// just in case we check and don't fuzz if the conversion to int for
		// random-number purposes would blow up
		if (interval > 0 && interval < Integer.MAX_VALUE) {
		mNextWakeup += mFuzzer.nextInt((int) interval);
		}
		setLocked(ELAPSED_REALTIME_WAKEUP, mNextWakeup);
		}
		if (firstBatch != firstWakeup) {
		nextNonWakeup = firstBatch.start;
		}
		}

		if (mPendingNonWakeupAlarms.size() > 0) {
		if (nextNonWakeup == 0 \|\| mNextNonWakeupDeliveryTime < nextNonWakeup) {
		nextNonWakeup = mNextNonWakeupDeliveryTime;