1 /* 2 * Copyright (c) 2015, 2019, 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 gc.arguments; 25 26 /* 27 * @test TestSelectDefaultGC 28 * @summary Test selection of GC when no GC option is specified 29 * @bug 8068582 30 * @key gc 31 * @library /test/lib 32 * @requires vm.gc=="null" 33 * @modules java.base/jdk.internal.misc 34 * java.management 35 * @run driver gc.arguments.TestSelectDefaultGC 36 */ 37 38 import jdk.test.lib.process.OutputAnalyzer; 39 import jdk.test.lib.process.ProcessTools; 40 41 public class TestSelectDefaultGC { 42 public static void assertVMOption(OutputAnalyzer output, String option, boolean value) { 43 output.shouldMatch(" " + option + " .*=.* " + value + " "); 44 } 45 46 public static void testDefaultGC(boolean actAsServer) throws Exception { 47 String[] args = new String[] { 48 "-XX:" + (actAsServer ? "+" : "-") + "AlwaysActAsServerClassMachine", 49 "-XX:" + (actAsServer ? "-" : "+") + "NeverActAsServerClassMachine", 50 "-XX:+PrintFlagsFinal", 51 "-version" 52 }; 53 54 // Start VM without specifying GC 55 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args); 56 OutputAnalyzer output = new OutputAnalyzer(pb.start()); 57 output.shouldHaveExitValue(0); 58 59 final boolean isServer = actAsServer; 60 61 // Verify GC selection 62 // G1 is default for server class machines 63 assertVMOption(output, "UseG1GC", isServer); 64 // Serial is default for non-server class machines 65 assertVMOption(output, "UseSerialGC", !isServer); 66 // CMS is never default 67 assertVMOption(output, "UseConcMarkSweepGC", false); 68 } 69 70 public static void main(String[] args) throws Exception { 71 // Test server class machine 72 testDefaultGC(false); 73 74 // Test non-server class machine 75 testDefaultGC(true); 76 } 77 }