1 /*

     2  * Copyright (c) 2018, 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

    26  * @bug 8195100

    27  * @summary a short lived Symbol should be cleaned up

    28  * @library /test/lib

    29  * @modules java.base/jdk.internal.misc

    30  *          java.management

    31  * @requires (vm.debug == true)

    32  */

    33 

    34 import jdk.test.lib.Platform;

    35 import jdk.test.lib.process.OutputAnalyzer;

    36 import jdk.test.lib.process.ProcessTools;

    37 import java.util.Scanner;

    38 

    39 public class ShortLivedSymbolCleanup {

    40 

    41   static int getSymbolTableSize(ProcessBuilder pb) throws Exception {

    42     int size = 0;

    43 

    44     OutputAnalyzer analyzer = new OutputAnalyzer(pb.start());

    45     String output = analyzer.getStdout();

    46     analyzer.shouldHaveExitValue(0);

    47 

    48     // Split string into lines using platform independent end of line marker.

    49     String[] lines = output.split("\\R");

    50     for (String line : lines) {

    51       if (line.contains("Start size")) {

    52         // ex. "[0.023s][trace][symboltable] Start size: 32768 (15)"

    53         Scanner scanner = new Scanner(line);

    54         scanner.next(); // skip "[0.023s][trace][symboltable]"

    55         scanner.next(); // skip "Start"

    56         scanner.next(); // skip "size:"

    57         size = Integer.parseInt(scanner.next()); // process "32768"

    58         scanner.close();

    59       }

    60     }

    61 

    62     return size;

    63   }

    64 

    65   static void analyzeOutputOn(int size, ProcessBuilder pb) throws Exception {

    66     OutputAnalyzer analyzer = new OutputAnalyzer(pb.start());

    67     String output = analyzer.getStdout();

    68     analyzer.shouldHaveExitValue(0);

    69 

    70     // Split string into lines using platform independent end of line marker.

    71     String[] lines = output.split("\\R");

    72     for (String line : lines) {

    73       if (line.startsWith("  Total removed")) {

    74         // ex. "Total removed              13309"

    75         Scanner scanner = new Scanner(line);

    76         scanner.next(); // skip "Total"

    77         scanner.next(); // skip "removed"

    78         int removed = Integer.parseInt(scanner.next()); // process "13309"

    79         scanner.close();

    80 

    81         if (removed < (size/2)) {

    82           System.out.println(output);

    83           // We should have removed at least half of the temporary Symbols

    84           throw new RuntimeException("Did not clean dead temporary Symbols [removed:"+removed+", size:"+size+"]");

    85         }

    86       }

    87     }

    88   }

    89 

    90   public static void main(String[] args) throws Exception {

    91 

    92       if (Platform.isDebugBuild()) {

    93         {

    94           ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xlog:symboltable=trace",

    95                                                                     "-version");

    96           int size = getSymbolTableSize(pb);

    97 

    98           pb = ProcessTools.createJavaProcessBuilder("-XX:+PrintSymbolTableSizeHistogram",

    99                                                                     LotsOfTempSymbols.class.getName(),

   100                                                                     Integer.toString(size));

   101           analyzeOutputOn(size, pb);

   102         }

   103      }

   104   }

   105 

   106   static class LotsOfTempSymbols {

   107     public static void main(String [] args) {

   108       int size = 2*Integer.parseInt(args[0]);

   109       // Create enough temporary Symbols, that we are

   110       // guranteed to insert into every bucket twice,

   111       // and therefore have the table check for dead entries

   112       for (int i=0; i<size; i++) {

   113         try {

   114           Class.forName(String.format("%05d", i), false, null);

   115         } catch (java.lang.ClassNotFoundException e) {}

   116       }

   117     }

   118   }

   119 }