GCM: Wake with exact guarantees for heartbeat

This changes how the alarms for heartbeat pings are scheduled. Instead
of a repeating, inexact alarm that may be delayed (at least up to 15
minutes), either an exact alarm (below Android 4.4) or an interval is used
which ensures that the alarm fires between half the configured interval
and the configured interval. This interval allows the OS to optimize
alarms a bit. For Android 6.0 further adjustments are probably
necessary.
This commit is contained in:
Michael Hamann 2016-01-11 20:49:17 +01:00
parent 4a595038fb
commit e264144aea
1 changed files with 20 additions and 3 deletions

View File

@ -22,6 +22,7 @@ import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
@ -145,10 +146,25 @@ public class McsService extends Service implements Handler.Callback {
AlarmManager alarmManager = (AlarmManager) context.getSystemService(ALARM_SERVICE);
long delay = getCurrentDelay();
Log.d(TAG, "Scheduling reconnect in " + delay / 1000 + " seconds...");
alarmManager.set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime() + delay,
alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + delay,
PendingIntent.getBroadcast(context, 1, new Intent(ACTION_RECONNECT, null, context, TriggerReceiver.class), 0));
}
public void scheduleHeartbeat(Context context) {
AlarmManager alarmManager = (AlarmManager) context.getSystemService(ALARM_SERVICE);
Log.d(TAG, "Scheduling heartbeat in " + heartbeatMs / 1000 + " seconds...");
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + heartbeatMs, heartbeatIntent);
} else {
// with KitKat, the alarms become inexact by default, but with the newly available setWindow we can get inexact alarms with guarantees.
// Schedule the alarm to fire within the interval [heartbeatMs/2, heartbeatMs]
alarmManager.setWindow(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + heartbeatMs / 2, heartbeatMs / 2,
heartbeatIntent);
}
}
public synchronized static long getCurrentDelay() {
long delay = currentDelay == 0 ? 5000 : currentDelay;
if (currentDelay < 60000) currentDelay += 10000;
@ -181,7 +197,7 @@ public class McsService extends Service implements Handler.Callback {
WakefulBroadcastReceiver.completeWakefulIntent(intent);
}
}
return START_STICKY;
return START_REDELIVER_INTENT;
}
private synchronized void connect() {
@ -196,7 +212,7 @@ public class McsService extends Service implements Handler.Callback {
inputStream.start();
outputStream.start();
alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime(), heartbeatMs, heartbeatIntent);
scheduleHeartbeat(this);
} catch (Exception e) {
Log.w(TAG, "Exception while connecting!", e);
rootHandler.sendMessage(rootHandler.obtainMessage(MSG_TEARDOWN, e));
@ -340,6 +356,7 @@ public class McsService extends Service implements Handler.Callback {
ping.last_stream_id_received(inputStream.getStreamId());
}
send(ping.build());
scheduleHeartbeat(this);
} else {
Log.d(TAG, "Ignoring heartbeat, not connected!");
scheduleReconnect(this);