1 /*
   2 * Copyright (c) 2014, 2015, 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 /*
  25  * @test TestParallelGCThreads
  26  * @key gc
  27  * @bug 8059527
  28  * @summary Tests argument processing for ParallelGCThreads
  29  * @library /testlibrary
  30  * @modules java.base/sun.misc
  31  *          java.management
  32  * @run driver TestParallelGCThreads
  33  */
  34 
  35 import com.oracle.java.testlibrary.*;
  36 
  37 public class TestParallelGCThreads {
  38 
  39   public static void main(String args[]) throws Exception {
  40 
  41     // For each parallel collector (G1, Parallel, ParNew/CMS)
  42     for (String gc : new String[] {"G1", "Parallel", "ConcMarkSweep"}) {
  43 
  44       // Make sure the VM does not allow ParallelGCThreads set to 0
  45       String[] flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=0", "-XX:+PrintFlagsFinal", "-version"};
  46       ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
  47       OutputAnalyzer output = new OutputAnalyzer(pb.start());
  48       output.shouldHaveExitValue(1);
  49 
  50       // Do some basic testing to ensure the flag updates the count
  51       for (long i = 1; i <= 3; i++) {
  52         flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=" + i, "-XX:+PrintFlagsFinal", "-version"};
  53         long count = getParallelGCThreadCount(flags);
  54         Asserts.assertEQ(count, i, "Specifying ParallelGCThreads=" + i + " for " + gc + "GC does not set the thread count properly!");
  55       }
  56     }
  57   }
  58 
  59   public static long getParallelGCThreadCount(String flags[]) throws Exception {
  60     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
  61     OutputAnalyzer output = new OutputAnalyzer(pb.start());
  62     output.shouldHaveExitValue(0);
  63     String stdout = output.getStdout();
  64     return FlagsValue.getFlagLongValue("ParallelGCThreads", stdout);
  65   }
  66 }