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