1 /*
   2  * Copyright (c) 2014, 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 import java.io.BufferedInputStream;
  26 import java.io.ByteArrayOutputStream;
  27 import java.io.IOException;
  28 import java.util.concurrent.Callable;
  29 import java.util.Random;
  30 
  31 import com.oracle.java.testlibrary.Asserts;
  32 import com.oracle.java.testlibrary.ByteCodeLoader;
  33 import com.oracle.java.testlibrary.InfiniteLoop;
  34 import com.oracle.java.testlibrary.Utils;
  35 import sun.hotspot.WhiteBox;
  36 
  37 public final class Helper {
  38     public static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
  39     public static final Random RNG = Utils.getRandomInstance();
  40 
  41     private static final long THRESHOLD = WHITE_BOX.getIntxVMFlag("CompileThreshold");
  42     private static final String TEST_CASE_IMPL_CLASS_NAME
  43             = String.format("%sImpl", TestCase.class.getName());
  44     private static byte[] CLASS_DATA;
  45     static {
  46         try {
  47             CLASS_DATA = loadClassData(TEST_CASE_IMPL_CLASS_NAME);
  48         } catch (IOException e) {
  49             throw new Error("TESTBUG: cannot load class byte code", e);
  50         }
  51     }
  52 
  53     private Helper() {
  54     }
  55 
  56     public static void startInfiniteLoopThread(Runnable action) {
  57         startInfiniteLoopThread(action, 0L);
  58     }
  59 
  60     public static void startInfiniteLoopThread(Runnable action, long millis) {
  61         Thread t = new Thread(new InfiniteLoop(action, millis));
  62         t.setDaemon(true);
  63         t.start();
  64     }
  65 
  66     public static int callMethod(Callable<Integer> callable, int expected) {
  67         int result = 0;
  68         for (int i = 0; i < THRESHOLD; ++i) {
  69             try {
  70                 result = callable.call();
  71             } catch (Exception e) {
  72                 throw new AssertionError(
  73                         "Exception occurred during test method execution", e);
  74             }
  75             Asserts.assertEQ(result, expected, "Method returns unexpected value");
  76         }
  77         return result;
  78     }
  79 
  80     private static byte[] loadClassData(String name) throws IOException {
  81         try (BufferedInputStream in = new BufferedInputStream(
  82                 ClassLoader.getSystemResourceAsStream(name.replace(".", "/")
  83                         + ".class"))) {
  84             ByteArrayOutputStream result = new ByteArrayOutputStream();
  85             byte[] buffer = new byte[1024];
  86             int read;
  87             while ((read = in.read(buffer)) != -1) {
  88                 result.write(buffer, 0, read);
  89             }
  90             return result.toByteArray();
  91         }
  92     }
  93 
  94     public interface TestCase {
  95 
  96         public static TestCase get() {
  97             try {
  98                 Class clazz = ByteCodeLoader.load(
  99                         TEST_CASE_IMPL_CLASS_NAME, CLASS_DATA);
 100                 return (TestCase) clazz.newInstance();
 101             } catch (ReflectiveOperationException e) {
 102                 throw new Error(String.format(
 103                         "TESTBUG: error while creating %s instance from reloaded class",
 104                         TEST_CASE_IMPL_CLASS_NAME), e);
 105             }
 106         }
 107 
 108         Callable<Integer> getCallable();
 109         int method();
 110         int expectedValue();
 111     }
 112 
 113     public static class TestCaseImpl implements TestCase {
 114         private static final int RETURN_VALUE = 42;
 115         private static final int RECURSION_DEPTH = 10;
 116         private volatile int i;
 117 
 118         @Override
 119         public Callable<Integer> getCallable() {
 120             return () -> {
 121                 i = 0;
 122                 return method();
 123             };
 124         }
 125 
 126         @Override
 127         public int method() {
 128             ++i;
 129             int result = RETURN_VALUE;
 130             if (i < RECURSION_DEPTH) {
 131                 return result + method();
 132             }
 133             return result;
 134         }
 135 
 136         @Override
 137         public int expectedValue() {
 138             return RETURN_VALUE * RECURSION_DEPTH;
 139         }
 140     }
 141 
 142 }