am 04eb368d: Merge "Prevent some alarm pathologies" into lmp-mr1-dev (f066bf22) · Commits · e / os / android_frameworks_base

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

+20 −1

Original line number	Diff line number	Diff line
		@@ -75,6 +75,12 @@ class AlarmManagerService extends SystemService {
		// warning message. The time duration is in milliseconds.
		private static final long LATE_ALARM_THRESHOLD = 10 * 1000;

		// Minimum futurity of a new alarm
		private static final long MIN_FUTURITY = 5 * 1000; // 5 seconds, in millis

		// Minimum alarm recurrence interval
		private static final long MIN_INTERVAL = 60 * 1000; // one minute, in millis

		private static final int RTC_WAKEUP_MASK = 1 << RTC_WAKEUP;
		private static final int RTC_MASK = 1 << RTC;
		private static final int ELAPSED_REALTIME_WAKEUP_MASK = 1 << ELAPSED_REALTIME_WAKEUP;
		@@ -696,6 +702,15 @@ class AlarmManagerService extends SystemService {
		windowLength = AlarmManager.INTERVAL_HOUR;
		}

		// Sanity check the recurrence interval. This will catch people who supply
		// seconds when the API expects milliseconds.
		if (interval > 0 && interval < MIN_INTERVAL) {
		Slog.w(TAG, "Suspiciously short interval " + interval
		+ " millis; expanding to " + (int)(MIN_INTERVAL/1000)
		+ " seconds");
		interval = MIN_INTERVAL;
		}

		if (type < RTC_WAKEUP \|\| type > ELAPSED_REALTIME) {
		throw new IllegalArgumentException("Invalid alarm type " + type);
		}
		@@ -709,7 +724,11 @@ class AlarmManagerService extends SystemService {
		}

		final long nowElapsed = SystemClock.elapsedRealtime();
		final long triggerElapsed = convertToElapsed(triggerAtTime, type);
		final long nominalTrigger = convertToElapsed(triggerAtTime, type);
		// Try to prevent spamming by making sure we aren't firing alarms in the immediate future
		final long minTrigger = nowElapsed + MIN_FUTURITY;
		final long triggerElapsed = (nominalTrigger > minTrigger) ? nominalTrigger : minTrigger;

		final long maxElapsed;
		if (windowLength == AlarmManager.WINDOW_EXACT) {
		maxElapsed = triggerElapsed;