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
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  22 */
  23 
  24 /*
  25  * @test TestParallelGCThreads
  26  * @key gc
  27  * @bug 8059527 8081382
  28  * @summary Tests argument processing for ParallelGCThreads
  29  * @library /test/lib
  30  * @modules java.base/jdk.internal.misc
  31  *          java.management
  32  * @run driver TestParallelGCThreads
  33  */
  34 
  35 import jdk.test.lib.Asserts;
  36 import jdk.test.lib.process.OutputAnalyzer;
  37 import jdk.test.lib.process.ProcessTools;
  38 
  39 public class TestParallelGCThreads {
  40 
  41   public static void main(String args[]) throws Exception {
  42     testFlags();
  43     testDefaultValue();
  44   }
  45 
  46   private static final String flagName = "ParallelGCThreads";
  47 
  48   // uint ParallelGCThreads = 23 {product}
  49   private static final String printFlagsFinalPattern = " *uint *" + flagName + " *:?= *(\\d+) *\\{product\\} *";
  50 
  51   public static void testDefaultValue()  throws Exception {
  52     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
  53       "-XX:+UnlockExperimentalVMOptions", "-XX:+PrintFlagsFinal", "-version");
  54 
  55     OutputAnalyzer output = new OutputAnalyzer(pb.start());
  56     String value = output.firstMatch(printFlagsFinalPattern, 1);
  57 
  58     try {
  59       Asserts.assertNotNull(value, "Couldn't find uint flag " + flagName);
  60 
  61       Long longValue = new Long(value);
  62 
  63       // Sanity check that we got a non-zero value.
  64       Asserts.assertNotEquals(longValue, "0");
  65 
  66       output.shouldHaveExitValue(0);
  67     } catch (Exception e) {
  68       System.err.println(output.getOutput());
  69       throw e;
  70     }
  71   }
  72 
  73   public static void testFlags() throws Exception {
  74     // For each parallel collector (G1, Parallel, ParNew/CMS)
  75     for (String gc : new String[] {"G1", "Parallel", "ConcMarkSweep"}) {
  76 
  77       // Make sure the VM does not allow ParallelGCThreads set to 0
  78       String[] flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=0", "-XX:+PrintFlagsFinal", "-version"};
  79       ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
  80       OutputAnalyzer output = new OutputAnalyzer(pb.start());
  81       output.shouldHaveExitValue(1);
  82 
  83       // Do some basic testing to ensure the flag updates the count
  84       for (long i = 1; i <= 3; i++) {
  85         flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=" + i, "-XX:+PrintFlagsFinal", "-version"};
  86         long count = getParallelGCThreadCount(flags);
  87         Asserts.assertEQ(count, i, "Specifying ParallelGCThreads=" + i + " for " + gc + "GC does not set the thread count properly!");
  88       }
  89     }
  90 
  91     // 4294967295 == (unsigned int) -1
  92     // So setting ParallelGCThreads=4294967295 should give back 4294967295
  93     // and setting ParallelGCThreads=4294967296 should give back 0. (SerialGC is ok with ParallelGCThreads=0)
  94     for (long i = 4294967295L; i <= 4294967296L; i++) {
  95       String[] flags = new String[] {"-XX:+UseSerialGC", "-XX:ParallelGCThreads=" + i, "-XX:+PrintFlagsFinal", "-version"};
  96       long count = getParallelGCThreadCount(flags);
  97       Asserts.assertEQ(count, i % 4294967296L, "Specifying ParallelGCThreads=" + i + " does not set the thread count properly!");
  98     }
  99   }
 100 
 101   public static long getParallelGCThreadCount(String flags[]) throws Exception {
 102     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
 103     OutputAnalyzer output = new OutputAnalyzer(pb.start());
 104     output.shouldHaveExitValue(0);
 105     String stdout = output.getStdout();
 106     return FlagsValue.getFlagLongValue("ParallelGCThreads", stdout);
 107   }
 108 }