1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package android.surfacecomposition;
17
18import android.util.Log;
19
20/**
21 * This task will simulate CPU activity by consuming memory bandwidth from the system.
22 * Note: On most system the CPU and GPU will share the same memory.
23 */
24public class MemoryAccessTask {
25    private final static String TAG = "MemoryAccessTask";
26    private final static int BUFFER_SIZE = 32 * 1024 * 1024;
27    private final static int BUFFER_STEP = 256;
28    private boolean mStopRequested;
29    private WorkThread mThread;
30    private final Object mLock = new Object();
31
32    public class WorkThread extends Thread {
33        public void run() {
34            byte[] memory = new byte[BUFFER_SIZE];
35            while (true) {
36                synchronized (mLock) {
37                    if (mStopRequested) {
38                        break;
39                    }
40                }
41                long result = 0;
42                for (int index = 0; index < BUFFER_SIZE; index += BUFFER_STEP) {
43                    result += ++memory[index];
44                }
45                Log.v(TAG, "Processing...:" + result);
46            }
47        }
48    }
49
50    public void start() {
51        if (mThread != null) {
52            throw new RuntimeException("Work thread is already started");
53        }
54        mStopRequested = false;
55        mThread = new WorkThread();
56        mThread.start();
57    }
58
59    public void stop() {
60        if (mThread != null) {
61            synchronized (mLock) {
62                mStopRequested = true;
63            }
64            try {
65                mThread.join();
66            } catch (InterruptedException e) {
67                e.printStackTrace();
68            }
69        }
70    }
71}
72