Introduce perf tests for background text layout performance

/*

 * Copyright (C) 2018 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License"); you may not

 * use this file except in compliance with the License. You may obtain a copy of

 * the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the

 * License for the specific language governing permissions and limitations under

 * the License.

 */

package android.text;

import android.perftests.utils.BenchmarkState;

import android.perftests.utils.PerfStatusReporter;

import android.support.test.filters.LargeTest;

import android.support.test.runner.AndroidJUnit4;

import org.junit.Rule;

import org.junit.Test;

import org.junit.runner.RunWith;

import java.util.Random;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.atomic.AtomicBoolean;

import java.util.concurrent.TimeUnit;

@LargeTest

@RunWith(AndroidJUnit4.class)

public class StaticLayoutMultithreadPerfTest {

    private static final int WORD_LENGTH = 9;  // Random word has 9 characters.

    private static final int WORDS_IN_LINE = 8;  // Roughly, 8 words in a line.

    private static final boolean NO_STYLE_TEXT = false;

    private static TextPaint PAINT = new TextPaint();

    private static final int TEXT_WIDTH = WORDS_IN_LINE * WORD_LENGTH * (int) PAINT.getTextSize();

    public StaticLayoutMultithreadPerfTest() {}

    @Rule

    public PerfStatusReporter mPerfStatusReporter = new PerfStatusReporter();

    private CountDownLatch mStartLatch;

    private AtomicBoolean mThreadState;  // True for running, False for stopped.

    private static final long TIMEOUT_MS = 5000;

    private Thread[] startBackgroundThread(int numOfThreads) {

        mStartLatch = new CountDownLatch(numOfThreads);

        mThreadState = new AtomicBoolean(true);

        Thread[] threads = new Thread[numOfThreads];

        for (int i = 0; i < numOfThreads; ++i) {

            final int seed = i + 1;

            threads[i] = new Thread(new Runnable() {

                @Override

                public void run() {

                    final TextPerfUtils util = new TextPerfUtils();

                    util.resetRandom(seed);

                    mStartLatch.countDown();

                    while (mThreadState.get()) {

                        final CharSequence text = util.nextRandomParagraph(

                                WORD_LENGTH, NO_STYLE_TEXT);

                        StaticLayout.Builder.obtain(text, 0, text.length(), PAINT, TEXT_WIDTH)

                                .build();

                    }

                }

            });

        }

        for (int i = 0; i < numOfThreads; ++i) {

            threads[i].start();

        }

        try {

            mStartLatch.await(TIMEOUT_MS, TimeUnit.MILLISECONDS);

        } catch (InterruptedException e) {

            throw new RuntimeException(e);

        }

        return threads;

    }

    private void finishThreads(Thread[] threads) {

        mThreadState.set(false);

        for (Thread thread : threads) {

            try {

                thread.join();

            } catch (InterruptedException e) {

                throw new RuntimeException(e);

            }

        }

        mStartLatch = null;

        mThreadState = null;

    }

    private void runRandomTest(int numOfTotalThreads) {

        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();

        final TextPerfUtils util = new TextPerfUtils();

        Thread[] threads = startBackgroundThread(numOfTotalThreads - 1);

        while (state.keepRunning()) {

            state.pauseTiming();

            final CharSequence text = util.nextRandomParagraph(WORD_LENGTH, NO_STYLE_TEXT);

            state.resumeTiming();

            StaticLayout.Builder.obtain(text, 0, text.length(), PAINT, TEXT_WIDTH)

                    .setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_NONE)

                    .setBreakStrategy(Layout.BREAK_STRATEGY_SIMPLE)

                    .build();

        }

        finishThreads(threads);

    }

    @Test

    public void testCreate_RandomText_Thread_1() {

        runRandomTest(1);

    }

    @Test

    public void testCreate_RandomText_Thread_2() {

        runRandomTest(2);

    }

    @Test

    public void testCreate_RandomText_Thread_4() {

        runRandomTest(4);

    }

}