| /* |
| * Copyright (C) 2019 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.gameperformance; |
| |
| /** |
| * Ballast thread that emulates CPU load by performing heavy computation in loop. |
| */ |
| public class CPULoadThread extends Thread { |
| private boolean mStopRequest; |
| |
| public CPULoadThread() { |
| mStopRequest = false; |
| } |
| |
| private static double computePi() { |
| double accumulator = 0; |
| double prevAccumulator = -1; |
| int index = 1; |
| while (true) { |
| accumulator += ((1.0 / (2.0 * index - 1)) - (1.0 / (2.0 * index + 1))); |
| if (accumulator == prevAccumulator) { |
| break; |
| } |
| prevAccumulator = accumulator; |
| index += 2; |
| } |
| return 4 * accumulator; |
| } |
| |
| // Requests thread to stop. |
| public void issueStopRequest() { |
| synchronized (this) { |
| mStopRequest = true; |
| } |
| } |
| |
| @Override |
| public void run() { |
| // Load CPU by PI computation. |
| while (computePi() != 0) { |
| synchronized (this) { |
| if (mStopRequest) { |
| break; |
| } |
| } |
| } |
| } |
| } |