android - redirect to the app in less than 3 second -

i'm trying develop android app prevent user exit app using exit button.

i'm using broad cast receiver, in onreceive check if current running app app; if yes --> continue, else --> redirect app.

my question now: interval in receiver ( 3 second ) app takes 5-6 second re-open app, how can redirect app in less 3 second?

code:

manifest declaration:

<receiver android:name=".alarmreciever" /> 

implementation of receiver:

public class alarmreciever extends broadcastreceiver {     @override     public void onreceive(context context, intent intent) {              activitymanager am1 = (activitymanager)context.getsystemservice(activity.activity_service);         string packagename = am1.getrunningtasks(1).get(0).topactivity.getpackagename();          if (packagename.equals("com.xxxx.yyyyy")) {             //continue;         }else{             final intent intent = new intent();             intent.setflags(intent.flag_activity_new_task);             intent.setclassname("com.xxxx.yyyyy", "com.xxxx.yyyyy.launch");             thisactivity.startactivity(intent);             thisactivity.finish();         }     } } 

do want give provision exit own app? if that's case why have use broadcast receivers? why not try

android.os.process.killprocess(android.os.process.mypid());

onbackpressed() method?