test/runtime/CommandLine/OptionsValidation/common/optionsvalidation/JVMOptionsUtils.java

*** 1,7 ****
  /*
!  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 25,34 ****
--- 25,36 ----
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.Reader;
+ import java.lang.management.GarbageCollectorMXBean;
+ import java.lang.management.ManagementFactory;
  import java.math.BigDecimal;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.LinkedHashMap;
*** 48,57 ****
--- 50,62 ----
      private static final StringBuilder finalFailedMessage = new StringBuilder();
  
      /* Used to start the JVM with the same type as current */
      static String VMType;
  
+     /* Used to start the JVM with the same GC type as current */
+     static String GCType;
+ 
      private static Map<String, JVMOption> optionsAsMap;
  
      static {
          if (Platform.isServer()) {
              VMType = "-server";
*** 62,71 ****
--- 67,97 ----
          } else if (Platform.isGraal()) {
              VMType = "-graal";
          } else {
              VMType = null;
          }
+ 
+         List<GarbageCollectorMXBean> gcMxBeans = ManagementFactory.getGarbageCollectorMXBeans();
+ 
+         GCType = null;
+ 
+         for (GarbageCollectorMXBean gcMxBean : gcMxBeans) {
+             switch (gcMxBean.getName()) {
+                 case "ConcurrentMarkSweep":
+                     GCType = "-XX:+UseConcMarkSweepGC";
+                     break;
+                 case "MarkSweepCompact":
+                     GCType = "-XX:+UseSerialGC";
+                     break;
+                 case "PS Scavenge":
+                     GCType = "-XX:+UseParallelGC";
+                     break;
+                 case "G1 Old Generation":
+                     GCType = "-XX:+UseG1GC";
+                     break;
+             }
+         }
      }
  
      public static boolean fitsRange(String optionName, BigDecimal number) throws Exception {
          JVMOption option;
          String minRangeString = null;
*** 441,450 ****
--- 467,480 ----
          }
  
          if (VMType != null) {
              runJava.add(VMType);
          }
+ 
+         if (GCType != null) {
+             runJava.add(GCType);
+         }
          runJava.add(PRINT_FLAGS_RANGES);
          runJava.add("-version");
  
          p = ProcessTools.createJavaProcessBuilder(runJava.toArray(new String[0])).start();
  
*** 532,542 ****
       * occurred while reading the data
       */
      public static Map<String, JVMOption> getOptionsWithRangeAsMap(String... additionalArgs) throws Exception {
          return getOptionsWithRangeAsMap(origin -> true, additionalArgs);
      }
- 
-     /* Simple method to test that java start-up. Used for testing options. */
-     public static void main(String[] args) {
-         System.out.print("Java start-up!");
-     }
  }
--- 562,567 ----