1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 package com.oracle.java.testlibrary.gc; 25 26 import java.lang.management.ManagementFactory; 27 import java.lang.management.MemoryUsage; 28 29 /** 30 * Prints memory usage to standard output 31 */ 32 public class MemoryUsagePrinter { 33 34 public static String humanReadableByteCount(long bytes, boolean si) { 35 int unit = si ? 1000 : 1024; 36 if (bytes < unit) { return bytes + " B"; } 37 int exp = (int) (Math.log(bytes) / Math.log(unit)); 38 String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i"); 39 return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre); 40 } 41 42 public static void printMemoryUsage(String label) { 43 MemoryUsage memusage = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage(); 44 float freeratio = 1f - (float) memusage.getUsed() / memusage.getCommitted(); 45 System.out.format( "[%-24s] init: %-7s, used: %-7s, comm: %-7s, freeRatio ~= %.1f%%%n", 46 label, 47 humanReadableByteCount( memusage.getInit(), true ), 48 humanReadableByteCount( memusage.getUsed(), true ), 49 humanReadableByteCount( memusage.getCommitted(), true ), 50 freeratio * 100 51 ); 52 } 53 }