Android studio getSlotFromBufferLocked: unknown buffer error

Question

I want to make a simple login and register app, so the user can create an account. (name, username, password) I use WAMP and a MYSQL database where I store the accounts.

When I fill in the user info on the registration form and click register I get the following error:

09-14 09:30:39.864    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7115e0
09-14 09:30:48.632    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7125a0
09-14 09:30:51.940    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7125a0

When I go check the database it didn't store the account.

MainActivity.java

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void userReg(View v)
    {
        startActivity(new Intent(this, Register.class));
    }
    public void userLogin(View view)
    {


    }


}

Register.java

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;

public class Register extends Activity {
    EditText ET_NAME,ET_USER_NAME,ET_USER_PASS;
    String name,user_name,user_pass;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.register_layout);
        ET_NAME = (EditText) findViewById(R.id.name);
        ET_USER_NAME = (EditText) findViewById(R.id.new_user_name);
        ET_USER_PASS = (EditText) findViewById(R.id.new_user_pass);
    }

    public void userReg(View view)
    {
        name = ET_NAME.getText().toString();
        user_name = ET_USER_NAME.getText().toString();
        user_pass = ET_USER_PASS.getText().toString();
        String method = "register";
        BackgroundTask backgroundTask = new BackgroundTask(Register.this);
        backgroundTask.execute(method,name,user_name,user_pass);
        finish();
    }
}

Backgroundtask.java

import android.app.AlertDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class BackgroundTask extends AsyncTask<String, Void, String> {
    AlertDialog alertDialog;
    Context ctx;

    BackgroundTask(Context ctx) {
        this.ctx = ctx;

    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        String reg_url = "http://10.0.2.2.2/webapp/register.php";
        String login_url = "http://10.0.2.2.2/webapp/login.php";
        String method = params[0];
        if (method.equals("register")) {
            String name = params[1];
            String user_name = params[2];
            String user_pass = params[3];
            try {
                URL url = new URL(reg_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                OutputStream OS = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(OS, "UTF-8"));
                String data = URLEncoder.encode("user", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
                        URLEncoder.encode("user_name", "UTF-8") + "=" + URLEncoder.encode(user_name, "UTF-8") + "&" +
                        URLEncoder.encode("user_pass", "UTF-8") + "=" + URLEncoder.encode(user_pass, "UTF-8");
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                OS.close();
                InputStream IS = httpURLConnection.getInputStream();
                IS.close();
                return "Registration Success...";
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
    }
}

register.php

<?php
require "init.php";
$name = $_POST["user"];
$user_name = $_POST["user_name"];
$user_pass = $_POST["user_pass"];

$sql_query = "insert into user_info values('$name','$user_name','$user_pass');";

if(mysqli_query($con,$sql_query))
{
//echo"<h3> Data insertion success...</h3>";
}
else{
//echo "Data insertion error..".mysqli_error($con);
}



?>

init.php

<?php
$db_name="myDBname";
$mysql_user = "root";
$mysql_pass = "root";
$server_name="localhost";

$con = mysqli_connect($server_name,$mysql_user,$mysql_pass,$db_name);
if(!$con)
{
//echo"Connection Error".mysqli_connect_error();
}
else
{
//echo"<h3> Database connection success.....</h3>";
}


?>

thanks, I checked my php files and I don't think the problem lies there. — Rob12, Sep 14 '15 at 10:04
Okay thank you very much, appreciate it. I just added the PHP scripts, just in case. — Rob12, Sep 14 '15 at 10:18
I'm running through "Android Programming 2ed" and I repeatedly get errors like _E/Surface: getSlotFromBufferLocked: unknown buffer: 0xabe2d840_ . what would cause that? — Matthew Cornell, Oct 14 '15 at 14:47
m having same prob , but my registration data will able to store in db but when i try to login, it cause this error and i can not login . anyone have solution?? — RKosamia, Nov 22 '15 at 22:56

Itai Hanski · Answer 1 · 2017-10-08T11:12:25.510

58

Edit:

This was a bug in Android that was fixed in later versions of Marshmallow

Original:

I believe that this is Marshmallow specific. Are you using a Marshmallow device?

I've noticed this error is printed out every time I switch between applications (doesn't matter which) or exit out of them, and when activities are destroyed.

I've tried running the same apps on two Nexus 5s - one running Lollipop and the other Marshmallow, and these log prints only appeared on the Marshmallow version - with every app, not just the one I'm building.

Not sure why this happens, but I opened a report here.

edited Oct 08 '17 at 11:12

answered Oct 21 '15 at 14:27

Itai Hanski

8,540
5
45
65

1

Yep. Confirmed as @Itai Hanski said. It's marshmallow specific. Switch your API level to a different one. – kirobo Nov 08 '15 at 14:16
@ShylendraMadda: They fixed this problem in in Android 6.0.1: https://code.google.com/p/android/issues/detail?id=192357#c18 – mhellmeier Mar 04 '16 at 16:01
This is not specific for marshmallow, I have 5.1.1 (lollipop) and also I get this error. I think this is related to reading and writing data on the SQLite database. Indeed, the buffer is locked and you have not any permission for accessibility. Try https://github.com/DezQ/ContactManager , which is a complete sample integrated with SQLite. – Hosein Aqajani Jun 19 '16 at 10:00

score 3 · Answer 2 · answered Oct 15 '15 at 10:36

I think you are finishing the context before backgrounTask finish, and Context you pass no longer exist.
You can try:

Use appContext : new BackgroundTask(Register.this.getApplicationContext());
Or, Wait for BackgroundTask finish : remove finish() after .execute(...) and add finish() onPostExecute

score 3 · Answer 3 · edited Aug 19 '16 at 12:04

I don't have specific problem's solution. But I had similar problem. Anyone who has problem like this please make sure you have below code.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.<YOUR_XML_FILE_NAME>);

by using intelligence you might have choose below code:

@Override
public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
    super.onCreate(savedInstanceState, persistentState);
    setContentView(R.layout.<YOUR_XML_FILE_NAME>);
}

This worked for me

For more info on PersistentState

Happy coding :)

score 2 · Answer 4 · answered Dec 11 '15 at 12:50

2

Update your android OS to 6.0.1.

This was an open issue found here. The issue is fixed in Android 6.0.1 which was publicly released recently.

answered Dec 11 '15 at 12:50

Nouman Rasheed

61
6

score 1 · Answer 5 · answered Nov 14 '15 at 23:27

It's quite strange but in my case i got this error when tried loading contacts without adding

<uses-permission android:name="android.permission.READ_CONTACTS" />

into manifest. And it disappeared just I've done it.

So my guess it's might be something with new permissions in Marshmallow.

Tested on my Nexus 5 with Android 6.0 and with targetSdkVersion 23 in build.gradle

score 1 · Answer 6 · answered Jul 26 '16 at 03:10

Since that android changed permissions request (some permissions like android.permission.READ_PHONE_STATE or android.permission.READ_CONTACTS), when you ask for these permissions at runtime and dont add the permission tag (<uses-permission android:name="..." />) in manifest, you will get the error.

So just use tag permissions like old versions and add request permission at runtime in newer versions.

Android studio getSlotFromBufferLocked: unknown buffer error

6 Answers6

Edit:

Original:

Linked