/* * Copyright (C) 2012, 2016 higherfrequencytrading.com * Copyright (C) 2016 Roman Leventov * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package net.openhft.chronicle.map; /** * Created by peter.lawrey on 28/02/14. */ public class PageLatencyMain { public static final int PAGES = Integer.getInteger("pages", 1024 * 1024); public static final int PAGES_SIZE = 512; // longs public static volatile long b; public static void main(String... ignored) { long[] bytes = new long[PAGES * PAGES_SIZE]; long maxTime = 0; for (int j = 0; j < 10; j++) { for (int i = 0; i < PAGES; i++) { long start0 = System.nanoTime(); b = bytes[i * PAGES_SIZE]; if (b != 0) throw new AssertionError(); long time = System.nanoTime() - start0; if (time > maxTime) maxTime = time; if (time > 1e5) System.out.println("Page access time was " + time / 100000 / 10.0 + " ms"); } } System.out.println("Longest page access time was " + maxTime / 10000 / 100.0 + " ms"); } }