Analyzing Android performance issues. This tutorial describes the available tools in Android to perform a performance analysis of Android applications.

1. Overview

It is very important for Android applications to perform all operations as fast as possible. This description lists the available tools to trace and optimize your Android application.

2. Android Basics

The following assumes that you have already basic knowledge in Android development. Please check the https://www.vogella.com/tutorials/Android/article.html - Android development tutorial to learn the basics.

3. StrictMode

You should avoid performing long running operations on the UI thread. This includes file and network access.

To ensure this you can use StrictMode. StrictMode is available as of API 9 (Android 2.3.3) and allows to setup thread policies for your application.

Via StrictMode you can instruct the Android system to crash your application if it performs long running operations, e.g. I/O in the user interface thread.

The following code shows how to use StrictMode. As the activity violates these settings it will crash.

package de.vogella.android.strictmode;

import java.io.BufferedWriter;
import java.io.OutputStreamWriter;

import android.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;

public class TestStrictMode extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Activate StrictMode
        StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
                .detectAll()
                .detectDiskReads()
                .detectDiskWrites()
                .detectNetwork()
                 // alternatively .detectAll() for all detectable problems
                .penaltyLog()
                .penaltyDeath()
                .build());
        StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
                .detectLeakedSqlLiteObjects()
                .detectLeakedClosableObjects()
                // alternatively .detectAll() for all detectable problems
                .penaltyLog()
                .penaltyDeath()
                .build());

        // Test code
        setContentView(R.layout.main);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        String eol = System.getProperty("line.separator");
        try {
            BufferedWriter writer =
                    new BufferedWriter(
                            new OutputStreamWriter(
                            openFileOutput("myfile",
                            MODE_WORLD_WRITEABLE)));
            writer.write("This is a test1." + eol);
            writer.write("This is a test2." + eol);
            writer.write("This is a test3." + eol);
            writer.write("This is a test4." + eol);
            writer.write("This is a test5." + eol);
            writer.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

StrictMode should only be used during development and not in your live application.

4. Developer Settings

Developer Settings in your Setting application of your Android phone allow to set configurations which simplify the analysis of your application. For example you can enable that the touch area is highlighted.

If you have a phone with Android 4.2, try going to the About section in the Settings and tap the Build number entry 7 times.

If you phone does not have this option try using an emulator.

In some cases you need to restart the application to make the setting work.

5. Traceview

5.1. Introduction

Traceview is a graphical viewer to see logs created by an Android application. Via Traceview you can measure the performance of your application to identify performance problems.

Traceview is located as standalone tool in the tools folder of your Android SDK installation folder and it also integrated into Eclipse via the Android Developer Tools (ADT).

5.2. Using Traceview from Android Studio

Android Studio supports tracing via the Android Device Monitor. Use Tools  Android  Android Device Monitor to open it.

To start tracing an application select your application process in the Devices view and select the Start Method Profiling button as depicted in the following screenshot.

traceview10

Use your application and re-press the same button to stop profiling. This will open a new editor which shows you the tracing results.

traceview20
traceview20

You can zoom into the graphic to get more details. To zoom out, double-click on the time line.

5.3. Using TraceView from the command line

To start tracing some code put the following code snippet around it.

android.os.Debug.startMethodTracing("yourstring");

// ... your code is here

android.os.Debug.stopMethodTracing();

The parameter "yourstring" tells the system that it should store the data under "/sdcard/yourstring.trace". To save data on the sdcard your application needs the WRITE_EXTERNAL_STORAGE permission. After running your application you can copy the results from the device via the adb command line tool.

adb pull /sdcard/yourstring.trace
traceview yourstring

This will start Traceview which allow you to analyze your performance data via a graphical way. The DDMS view has also a trace button available. This will trace the running application and does not require an additional authorization.

6. Exercise: Traceview

6.1. Create example project

Create an Android application with the top level package called com.vogella.android.traceview.

Add the following key to your values/strings.xml file.

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Traceview Example</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string name="number_template"><b>Random number: %1$s</b></string>

</resources>

Create the following layout file called rowlayout.xml.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:orientation="horizontal" >

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/textView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Entry"
                android:textAppearance="?android:attr/textAppearanceListItem" />

            <TextView
                android:id="@+id/textView2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Stub"
                android:textAppearance="?android:attr/textAppearanceListItemSmall" />
        </LinearLayout>
    </LinearLayout>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="10dp"
        android:layout_height="?android:attr/listPreferredItemHeight"
        android:background="@android:color/black" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="Medium Text"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

Implement the following adapter for your ListView.

package com.vogella.android.traceview;

import java.util.Collections;
import java.util.List;

import android.content.Context;
import android.content.res.Resources;
import android.os.Debug;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class MyArrayAdapter extends ArrayAdapter<String> {

    private List<String> values;
    private Context context;

    public MyArrayAdapter(Context context, List<String> values) {
        super(context, R.layout.rowlayout);
        this.context = context;
        this.values = values;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        Debug.startMethodTracing("getViewOfTrace");
        // Ensure sorted values
        Collections.sort(values);
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.rowlayout, parent, false);
        Resources res = context.getResources();
        String text = String.format(res.getString(R.string.number_template),
                values.get(position));
        CharSequence styledText = Html.fromHtml(text);
        TextView textView = (TextView) view.findViewById(R.id.textView3);
        textView.setText(styledText);
        Debug.stopMethodTracing();
        return view;
    }
}

Implement a ListView in the activity which shows 1000 random generated strings.

package com.vogella.android.traceview;

import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.List;

import android.app.ListActivity;
import android.os.Bundle;

public class MainActivity extends ListActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        List<String> list = createValues();
        MyArrayAdapter adapter = new MyArrayAdapter(this, list);
        setListAdapter(adapter);
    }

    private static List<String> createValues() {
        SecureRandom random = new SecureRandom();
        List<String> list = new ArrayList<String>();
        for (int i = 0; i < 1000; i++) {
            String string = new BigInteger(130, random).toString(32);
            list.add(string);
        }
        return list;
    }

}

Add the permission to write on external storage to your application.

6.2. Perform trace

Run your application. Afterwards connect to your device via adb and copy the resulting performance trace to your drive. Analyze the result.

6.3. Solve performance problems

Improve the performance based on the measurements of Traceview. Here are some pointers what to improve.

  • Replace the bold styling in the getView() method with the corresponding android:textStyle="bold attribute in your layout to avoid the Html.fromHtml() call.

  • Move the sorting to another place

  • Reuse convertView in your Adapter, if not null

  • Avoid the findViewById() method call by using the HolderPattern in your ListView

The layout is also not optimized. We reuse this exercise in the exercise for the HierarchyView

7. Hierarchy Viewer

The Hierarchy View perspective allows you to visualize the View hierarchy of your Android application and helps you to identify unnecessary layers in this hierarchy.

You can open the Hierarchy View via Window  Open Perspective  Other…​  Hierarchy View

In the Windows view you can select the process for which you want to analyze the view hierarchy.

Hierarchy Viewer for selecting the process

The currently active layout is analyzed and displayed.

Hierarchy Viewer

The Tree View view show three light bulbs for the views. The first one indicates the time for calculating the size of the view, the second one indicates the time for creating the layout and the third one for drawing the view. Performance intensive work is indicated with the yellow or red color.

8. Exercise: Hierarchy Viewer

Continue to use the same example as in the Traceview Excercise. Open the Hierarchy View perspective and analyze the view layer.

While none of these layout layers is very performance intensive it contains redundant layers and unnecessary views. Remove the unnecessary view layers.

9. Layout optimization

You should optimize your layout. The following gives an example how to use FrameLayout with an ImageView and one TextView to create result despicted in the next screenshot. It uses the possibility to position the TextView in the layout and to style parts of its text content differently.

Styling TextView with TextAppearanceSpan

Create a project called com.vogella.android.textview.spannablestring.

Add two news styles to your styles.xml file.

<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a API-level are here. -->
    </style>

    <style name="textHeader">
        <item name="android:padding">4dip</item>
        <item name="android:textAppearance">?android:attr/textAppearanceLarge</item>
        <item name="android:textColor">#000000</item>
        <item name="android:fontFamily">sans-serif-condensed</item>
    </style>

    <style name="textbody">
        <item name="android:padding">4dip</item>
        <item name="android:textAppearance">?android:attr/textAppearanceSmall</item>
        <item name="android:textSize">16sp</item>
        <item name="android:textColor">#c0c0c0</item>
    </style>

</resources>

Create the following layout.

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/FrameLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:id="@+id/input"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:layout_margin="16dp"
        android:text="@string/hello_world"
        android:textSize="32sp" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:contentDescription="image"
        android:src="@drawable/vogella" />

</FrameLayout>

Style your text in the TextView via separate TextAppearanceSpan as demonstrated in the following code.

package com.vogella.android.textview.spannablestring;

import android.app.Activity;
import android.os.Bundle;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.TextAppearanceSpan;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView textView = (TextView) findViewById(R.id.input);
        String header = "This is the header";
        String description = "This is the description";

        Spannable styledText = new SpannableString(header + "\n" + description);
        TextAppearanceSpan span1 = new TextAppearanceSpan(this,
                R.style.textHeader);
        TextAppearanceSpan span2 = new TextAppearanceSpan(this,
                R.style.textbody);
        styledText.setSpan(span1, 0, header.length(),
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        styledText.setSpan(span2, header.length() + 1, header.length() + 1
                + description.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        textView.setText(styledText);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

The resulting layout is much faster than a layout based on RelativeLayout. Also HTML styling was avoid as the HTML parser is relatively expensive.

10. Memory Dumps

You can create a memory snapshot and analyze it with the https://www.vogella.com/tutorials/EclipseMemoryAnalyzer/article.html - Eclipse Memory Analyzer.

11. Systrace

Systrace allows to measure the performance directly at kernel level. To enable systrace, select the Developer options and select the Enable traces entry. In the next dialog you can define what type of events should be profiled, e.g. Graphics and View.

Enable traces
Enable traces

To use systrace, open a terminal and run systrace.py from the android_sdk_installdir/tools/systrace directory. You may have to set it to executable (chmod a+x systrace.py on Linux).

You can also start Systrace directly from Eclipse via the DDMS perspective.

Systrace with ADT Part 1
Systrace with ADT Part 2

Systrace captures events for 5 seconds. As result Systrace creates a HTML file which allows you to analyze potential issues.

12. Simulating pixel density

You can use the command line to simulate different device densities and display resolutions.

This allows you to use a device with a high device density and resolution to simulate other devices.

// Set the display size
adb shell am display-size 600x800

// Set the display density
adb shell am display-density 80

13. Android templates

You can define your own templates for the Android project creation wizard. See the following links for more information.

14. Profile GPU rendering

In the Developer options in the Setting or your Android device you can activate Profile GPU rendering. With this option the system tracks the time it took to draw the last 128 frames.

After activating this and restarting your application you can get the information via the following command.

adb shell dumpsys gfxinfo your_package

To measure the frame rate of your application, e.g. by scrolling on a list view. In most cases you need to interact with your application to trigger that it re-draws itself.

In the resulting log, look for a section called Profile data in ms.

15. Analyzing Overdraw

Overdraw happens if you draw something on top of something else. For example an activity has a Window as background. If a TextView it added to the application, the TextView is drawn on top of the Window.

Overdrawn is therefore intended to happen. But unnecessary overdraw should be avoid to have the best performance possible.

Unnecessary overdraw can be caused by complex view hierarchies. In general a 2x overdraw (a pixel gets drawn three times) is standard and expected but more should be avoided.

You can enable a visualization of overdraw via the Development Settings with the Show GPU overdraw setting. This section adds colors to your screen based on the number of overdraws. The following table explains the used color schema.

Table 1. Overdrawn colors
Color Meaning

No color

No overdraw

Blue

1x overdraw, pixel was painted twice

Green

2x

Light red

3x, might indicate a problem, small red areas are still ok

Dark red

4x, pixel was pained 5 times or more, indicates a problem.

After visualization of potential problematic areas, you can analyze your View hierarchy with the Hierarchy Viewer.

16. Useful open source tools for application analysis

16.1. Using Leak Canary to find memory leaks

Leak Canary can be integrated into an Android application and can detect automatically leaks of activities and fragments. The usage is very simple, you add it as dependency to your Gradle build file and initialize the library in your application class. This registers a life cycle listener for your activities and traces if their destroy method is called in the right point in time.

As Leak Canary is an Open Source project it is likely to change very quickly. See https://github.com/square/leakcanary - Leak Canarys Github page for instructions how to use it.

16.2. Using AndroidDevMetrics to display performance data

AndroidDevMetrics you can see how fast the most common operations like object initialization (in Dagger 2 graph), or Activity lifecycle methods (onCreate(), onStart(), onResume()) are.

As AndroidDevMetrics is an Open Source project. See https://github.com/frogermcs/androiddevmetrics - AndroidDevMetrics Github page for instructions how to use it.

17. Android Animation Resources

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