Am I leaking Context?

Question

I'm setting alarms in my app using AlarmManager from multiple Activities.

To avoid redundant code, I created the following class:

public class CustomAlarmManager {

    private static final String SHARED_PREF_REQUEST_CODE = "requestCode";
    private static final String KEY_REQUEST_CODE = "kRequestCode";

    private CustomAlarmManager() {
    }

    public static void setNewAlarm(Context context, long timeInMillis) {
        Intent intent = new Intent(SomeOtherClass.ALARM_ACTION);
        intent.putExtra(SomeOtherClass.KEY_ALARM_TIME, timeInMillis);

        PendingIntent pendingIntent = PendingIntent.getBroadcast(
                context.getApplicationContext(),
                getNewCode(context),
                intent,
                PendingIntent.FLAG_ONE_SHOT);
        AlarmManager am = (AlarmManager) context.getSystemService(ALARM_SERVICE);

        if (Build.VERSION.SDK_INT >= 23) {
            am.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP,
                timeInMillis, pendingIntent);
        } else if (Build.VERSION.SDK_INT >= 19) {
            am.setExact(AlarmManager.RTC_WAKEUP, timeInMillis, pendingIntent);
        } else {
            am.set(AlarmManager.RTC_WAKEUP, timeInMillis, pendingIntent);
        }
    }

    // this method is for generating unique int values
    // for the requestCode param of PendingIntent.getBroadcast()
    private static int getNewCode(Context context) {
        SharedPreferences prefs = context.getSharedPreferences(
            SHARED_PREF_REQUEST_CODE, MODE_PRIVATE);
        int oldCode = prefs.getInt(KEY_REQUEST_CODE, Integer.MIN_VALUE);
        int newCode = ++oldCode;
        prefs.edit().putInt(KEY_REQUEST_CODE, newCode).apply();

        return newCode;
    }
}

So when i'd like to set an alarm, i can just call the following from anywhere in my app:

CustomAlarmManager.setNewAlarm(aContext, someTimeInMillis);

My question:

Should I have to worry about leaking the Context here?

I'm not storing a reference to it, so I think I'm good, but I'm not sure.

Is this a good approach?

You even used applicationContext just in case ;) thats awesome ;) well done. — Amir Ziarati, Oct 11 '16 at 10:36

csenga · Answer 1 · 2016-10-11T10:05:17.420

2

Should I have to worry about leaking the Context here?

Definitely not.

You pass the context to the method and do your job with it right there. You do not even store it or use it later which could be the root of the evil in this case.

edited Oct 11 '16 at 10:05

answered Oct 11 '16 at 09:57

csenga

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score 2 · Accepted Answer · answered Oct 11 '16 at 10:17

I think there isnt any problem.

The leak problem normally happens when you need some task to be done in the future and you hold a reference to a currenctly available object (which may be killed before that task happens).

This also happens if a non static inner class object is sent as a parameter to be used in a specific time in the future. Since the non static inner class holds a reference to its father its gonna be a big memory leak.

1- you didnt hold any reference to your context for your future task

2- you didnt use a inner class and made your class as a separate file and methods are static.

So be sure you are safe and sound ;)

Am I leaking Context?

2 Answers2