Background sticky concurrent mark sweep GC freed

I have an application that checks the database every 10 seconds if there is any new data, if there is any data it will get it and stop checking the database.

I have implemented a text watcher to check if the textbox is empty. If it is, it will check the database, if it contains any text it will stop.

This is my code:

 @Override
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txtBoxUser.addTextChangedListener(checkUserRent); getData();
}
//TEXTWATCHER FOR GETTING PERSON WHO RENTED BOX
private final TextWatcher checkUserRent = new TextWatcher() { public void beforeTextChanged(CharSequence s, int start, int count, int after) { } public void onTextChanged(CharSequence s, int start, int before, int count) { } public void afterTextChanged(Editable s) { if (s.length() == 0) { check(); } else { Toast.makeText(MainActivity.this, "STOP", Toast.LENGTH_LONG).show(); } }
};
public void start(View view)
{ getData();
}
public void cancel(View view)
{ txtBoxUser.setText(""); txtBoxPasscode.setText("");
}
private void getData(){ final String id = txtBoxName.getText().toString().trim(); class GetEmployee extends AsyncTask<Void,Void,String>{ ProgressDialog loading; @Override protected void onPreExecute() { super.onPreExecute(); // loading = ProgressDialog.show(MainActivity.this,"Fetching...","Wait...",false,false); } @Override protected void onPostExecute(String s) { super.onPostExecute(s); // loading.dismiss(); showEmployee(s); } @Override protected String doInBackground(Void... params) { RequestHandler rh = new RequestHandler(); String s = rh.sendGetRequestParam(DATA_URL,id); return s; } } GetEmployee ge = new GetEmployee(); ge.execute();
}
private void showEmployee(String json){ try { JSONObject jsonObject = new JSONObject(json); JSONArray result = jsonObject.getJSONArray(JSON_ARRAY); JSONObject c = result.getJSONObject(0); String name = c.getString(GET_BOXUSER); String desg = c.getString(GET_PASSCODE); txtBoxUser.setText(name); txtBoxPasscode.setText(desg); } catch (JSONException e) { e.printStackTrace(); }
}
private void check()
{ getData();
}

But I get this in the logcat while it is waiting for the data. I am just wondering is it okay or safe?

I/art: Background sticky concurrent mark sweep GC freed 5614(449KB) AllocSpace objects, 18(288KB) LOS objects, 33% free, 1691KB/2MB, paused 5.354ms total 10.731ms
I/art: Background sticky concurrent mark sweep GC freed 7039(557KB) AllocSpace objects, 22(352KB) LOS objects, 39% free, 1561KB/2MB, paused 10.554ms total 15.931ms
I/art: Background partial concurrent mark sweep GC freed 7279(564KB) AllocSpace objects, 21(336KB) LOS objects, 40% free, 1504KB/2MB, paused 5.721ms total 15.823ms
I/art: WaitForGcToComplete blocked for 5.375ms for cause HeapTrim
I/art: Background partial concurrent mark sweep GC freed 7650(591KB) AllocSpace objects, 22(352KB) LOS objects, 40% free, 1505KB/2MB, paused 5.511ms total 21.465ms

3 Answers

This is perfectly fine. It means that you're using memory, then its being freed by the GC. Its only a problem is either you go out of memory, or you see performance hiccups due to garbage collection. But its not anything you need to race to fix.

I have had the same issue. Your code will work, but if this hangs for too long, the app can get a App Not Responding error and close. It also defeats the purpose of using an AsyncTask.

The issue is that your AsyncTask contains a text view so it will block any other actions while executing. To fix this, make your AsyncTask static and pass it a reference to the Text view. Then store it in a WeakReference.

static class GetEmployee extends AsyncTask<Void,Void,String>{ WeakReference<TextView> textUserWeakReference; WeakReference<TextView> textPassWeakReference; GetEmployee(TextView textUser, TextView textPass) { textUserWeakReference = new WeakReference<>(textUser); textPassWeakReference = new WeakReference<>(textPass); } @Override protected void onPreExecute() { super.onPreExecute(); // loading = ProgressDialog.show(MainActivity.this,"Fetching...","Wait...",false,false); } @Override protected void onPostExecute(String s) { super.onPostExecute(s); // loading.dismiss(); TextView textUser = textUserWeakReference.get(); TextView textPass = textPassWeakReference.get(); if(textView != null && textPass != null) showEmployee(s, textUser, textPass); } @Override protected String doInBackground(Void... params) { RequestHandler rh = new RequestHandler(); String s = rh.sendGetRequestParam(DATA_URL,id); return s; }
}
private static void showEmployee(String json, TextView txtBoxUser, TextView txtBoxPassCode){
try { JSONObject jsonObject = new JSONObject(json); JSONArray result = jsonObject.getJSONArray(JSON_ARRAY); JSONObject c = result.getJSONObject(0); String name = c.getString(GET_BOXUSER); String desg = c.getString(GET_PASSCODE); txtBoxUser.setText(name); txtBoxPasscode.setText(desg);
} catch (JSONException e) { e.printStackTrace();
}
}

I had the same problem, and it was called by an infinite loop. This was making my app crash.

I found the infinite loop, removed it, and now the app doesn't crash and I don't have these logs anymore.