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