1 /* 2 * Copyright (c) 2016, 2018, 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 sun.hotspot.gc; 25 26 import sun.hotspot.WhiteBox; 27 28 /** 29 * API to obtain information about selected and supported Garbage Collectors 30 * retrieved from the VM with the WhiteBox API. 31 */ 32 public enum GC { 33 /* 34 * Enum values must match CollectedHeap::Name 35 */ 36 Serial(1), 37 Parallel(2), 38 ConcMarkSweep(3), 39 G1(4), 40 Epsilon(5), 41 Z(6), 42 Shenandoah(7); 43 44 private static final WhiteBox WB = WhiteBox.getWhiteBox(); 45 46 private final int name; 47 48 private GC(int name) { 49 this.name = name; 50 } 51 52 /** 53 * @return true if this GC is supported by the VM, i.e., it is built into the VM. 54 */ 55 public boolean isSupported() { 56 return WB.isGCSupported(name); 57 } 58 59 /** 60 * @return true if this GC is currently selected/used 61 */ 62 public boolean isSelected() { 63 return WB.isGCSelected(name); 64 } 65 66 /** 67 * @return true if GC was selected ergonomically, as opposed 68 * to being explicitly specified on the command line 69 */ 70 public static boolean isSelectedErgonomically() { 71 return WB.isGCSelectedErgonomically(); 72 } 73 }