android - PowerManager wakelock not waking device up from service

Question

I've an app that has a background service running every minute. I want the service to wake the device up if it's asleep. I am using a PowerManager but the device doesn't wake up. Any ideas why? Thanks in advance.

@Override
protected void onHandleIntent(Intent intent) {
    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
    PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK,
            "My Tag");
    wl.acquire();
    // do work as device is awake
    wl.release();
}

[edit1]

This is how i start the service from an Activity.

// get a Calendar object with current time
Calendar cal = Calendar.getInstance();
// add 5 minutes to the calendar object
cal.add(Calendar.MINUTE, 1);
Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
intent.putExtra("alarm_message", "sending outstanding transactions");
// In reality, you would want to have a static variable for the
// request code instead of 192837
PendingIntent sender = PendingIntent.getBroadcast(
        getApplicationContext(), 192837, intent,
        PendingIntent.FLAG_UPDATE_CURRENT);
// Get the AlarmManager service
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
// am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), sender);
// 86400000 = 24 hours
// 43200000 = 12 hours
// 3600000 = 1hr
// 1800000 = 30 mins
// 300000 = 5 mins
am.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),60000,sender);

AlarmReceiver class

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
import android.os.Bundle;

public class AlarmReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        try {

            Bundle bundle = intent.getExtras();
            String message = bundle.getString("alarm_message");
            // Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
            Intent myIntent = new Intent(context,
                    SendOutstandingTransactions.class);
            myIntent.setAction("com.carefreegroup.startatboot.MyService");
            context.startService(myIntent);
        } catch (Exception e) {
            Toast.makeText(
                    context,
                    "There was an error somewhere, but we still received an alarm",
                    Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
    }
}

The following class calls the Activity which I want to start when the device is asleep.

SendOutstandingTransactions IntentService.

protected void onHandleIntent(Intent intent) {
    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
    PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK,
            "My Tag");
    wl.acquire();
    if (hasMessageDisplayed == false) {
        Intent i = new Intent(this, DisplayMessageActivity.class);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(i);
    }
    wl.release();
}

[edit2]

@Override
public void onDestroy() {
    super.onDestroy();
    PowerManager pm = (PowerManager) this.getSystemService(Context.POWER_SERVICE);
    PowerManager.WakeLock wl = pm.newWakeLock(
            PowerManager.PARTIAL_WAKE_LOCK, "com.something.alarm");
    // Acquire the lock
    if (wl.isHeld()) wl.release();
}

Answer 1

Either use Commonsware's WakefulIntentService or do this :

class YourService extends IntentService {

    private static final String LOCK_NAME = YourService.class.getName()
            + ".Lock";
    private static volatile WakeLock lockStatic = null; // notice static

    synchronized private static PowerManager.WakeLock getLock(Context context) {
        if (lockStatic == null) {
            PowerManager mgr = (PowerManager) context
                    .getSystemService(Context.POWER_SERVICE);
            lockStatic = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                    LOCK_NAME);
            lockStatic.setReferenceCounted(true);
        }
        return (lockStatic);
    }

    public static void startYourService(Context ctxt, Intent i) { // STATIC 
        getLock(ctxt.getApplicationContext()).acquire();
        ctxt.startService(i);
    }

    public YourService(String name) {
        super(name);
        setIntentRedelivery(true);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        PowerManager.WakeLock lock = getLock(this.getApplicationContext());
        if (!lock.isHeld() || (flags & START_FLAG_REDELIVERY) != 0) {
            lock.acquire();
        }
        super.onStartCommand(intent, flags, startId);
        return (START_REDELIVER_INTENT);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        try {
            // do your thing
        } finally {
            PowerManager.WakeLock lock = getLock(this.getApplicationContext());
            if (lock.isHeld()) lock.release();
        }
    }
}

and in your receiver :

Bundle bundle = intent.getExtras();
String message = bundle.getString("alarm_message");
// Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
Intent myIntent = new Intent(context, SendOutstandingTransactions.class);
myIntent.setAction("com.carefreegroup.startatboot.MyService");
YourService.startYourService(context, myIntent)

which is actually the core from @CommonsWare WakefulIntentService (not sure about the START_FLAG_REDELIVERY, I should ask one of these days)