--- a/hotspot/test/gc/g1/humongousObjects/Helpers.java	Thu Dec 10 16:18:25 2015 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,58 +0,0 @@
-/*
- * 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.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package gc.g1.humongousObjects;
-
-import sun.hotspot.WhiteBox;
-
-public class Helpers {
-
-    // In case of 128 byte padding
-    private static final int MAX_PADDING_SIZE = 128;
-
-    /**
-     * Detects amount of extra bytes required to allocate a byte array.
-     * Allocating a byte[n] array takes more then just n bytes in the heap.
-     * Extra bytes are required to store object reference and the length.
-     * This amount depends on bitness and other factors.
-     *
-     * @return byte[] memory overhead
-     */
-    public static int detectByteArrayAllocationOverhead() {
-
-        WhiteBox whiteBox = WhiteBox.getWhiteBox();
-
-        int zeroLengthByteArraySize = (int) whiteBox.getObjectSize(new byte[0]);
-
-        // Since we do not know is there any padding in zeroLengthByteArraySize we cannot just take byte[0] size as overhead
-        for (int i = 1; i < MAX_PADDING_SIZE + 1; ++i) {
-            int realAllocationSize = (int) whiteBox.getObjectSize(new byte[i]);
-            if (realAllocationSize != zeroLengthByteArraySize) {
-                // It means we did not have any padding on previous step
-                return zeroLengthByteArraySize - (i - 1);
-            }
-        }
-        throw new Error("We cannot find byte[] memory overhead - should not reach here");
-    }
-}

--- a/hotspot/test/gc/g1/humongousObjects/TestHumongousThreshold.java	Thu Dec 10 16:18:25 2015 +0100
+++ b/hotspot/test/gc/g1/humongousObjects/TestHumongousThreshold.java	Thu Dec 10 20:14:00 2015 +0300
@@ -24,6 +24,7 @@
 
 package gc.g1.humongousObjects;
 
+import gc.testlibrary.Helpers;
 import jdk.test.lib.Asserts;
 import sun.hotspot.WhiteBox;
 
@@ -31,10 +32,10 @@
  * @test TestHumongousThreshold
  * @summary Checks that objects larger than half a region are allocated as humongous
  * @requires vm.gc=="G1" | vm.gc=="null"
- * @library /testlibrary /test/lib
+ * @library /testlibrary /test/lib /
  * @modules java.management
  * @build sun.hotspot.WhiteBox
- *        gc.g1.humongousObjects.Helpers
+ *        gc.testlibrary.Helpers
  *        gc.g1.humongousObjects.TestHumongousThreshold
  * @run driver ClassFileInstaller sun.hotspot.WhiteBox
  *                                sun.hotspot.WhiteBox$WhiteBoxPermission

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/testlibrary/Helpers.java	Thu Dec 10 20:14:00 2015 +0300
@@ -0,0 +1,251 @@
+/*
+ * 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package gc.testlibrary;
+
+import jdk.test.lib.JDKToolLauncher;
+import jdk.test.lib.OutputAnalyzer;
+import sun.hotspot.WhiteBox;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class Helpers {
+
+    /**
+     * Size of a long field in bytes
+     */
+    public static final int SIZE_OF_LONG = 8;
+
+    // In case of 128 byte padding
+    private static final int MAX_PADDING_SIZE = 128;
+
+    /**
+     * According class file format theoretical amount of fields in class is u2 which is (256 * 256 - 1).
+     * Some service info takes place in constant pool and we really could make a class with only (256 * 256 - 29)
+     * fields.
+     * Since the exact value is not so important and I would like to avoid issues that may be caused by future changes/
+     * different archs etc I selected (256 * 256 - 32) for this constant.
+     * The test works with other values too but the smaller the number the more classes we need to generate and it takes
+     * more time
+     */
+    private static final int MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS = 256 * 256 - 32;
+
+    /**
+     * Detects amount of extra bytes required to allocate a byte array.
+     * Allocating a byte[n] array takes more then just n bytes in the heap.
+     * Extra bytes are required to store object reference and the length.
+     * This amount depends on bitness and other factors.
+     *
+     * @return byte[] memory overhead
+     */
+    public static int detectByteArrayAllocationOverhead() {
+
+        WhiteBox whiteBox = WhiteBox.getWhiteBox();
+
+        int zeroLengthByteArraySize = (int) whiteBox.getObjectSize(new byte[0]);
+
+        // Since we do not know is there any padding in zeroLengthByteArraySize we cannot just take byte[0] size as overhead
+        for (int i = 1; i < MAX_PADDING_SIZE + 1; ++i) {
+            int realAllocationSize = (int) whiteBox.getObjectSize(new byte[i]);
+            if (realAllocationSize != zeroLengthByteArraySize) {
+                // It means we did not have any padding on previous step
+                return zeroLengthByteArraySize - (i - 1);
+            }
+        }
+        throw new Error("We cannot find byte[] memory overhead - should not reach here");
+    }
+
+    /**
+     * Compiles a java class
+     *
+     * @param className class name
+     * @param root      root directory - where .java and .class files will be put
+     * @param source    class source
+     * @throws IOException if cannot write file to specified directory
+     */
+    public static void compileClass(String className, Path root, String source) throws IOException {
+        Path sourceFile = root.resolve(className + ".java");
+        Files.write(sourceFile, source.getBytes());
+
+        JDKToolLauncher jar = JDKToolLauncher.create("javac")
+                .addToolArg("-d")
+                .addToolArg(root.toAbsolutePath().toString())
+                .addToolArg("-cp")
+                .addToolArg(System.getProperty("java.class.path") + File.pathSeparator + root.toAbsolutePath())
+                .addToolArg(sourceFile.toAbsolutePath().toString());
+
+        ProcessBuilder pb = new ProcessBuilder(jar.getCommand());
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldHaveExitValue(0);
+    }
+
+    /**
+     * Generates class with specified name, which extends specified class, with specified constructor and specified
+     * count of long fields
+     * Generated class will looks like this:
+     * public class ClassName extends SuperClass {
+     * ClassName() {super();}
+     * long f0;
+     * ...
+     * long fNNN;
+     * <p>
+     * }
+     *
+     * @param className   class name
+     * @param superClass  super class. if null - no extends clause
+     * @param constructor constructor. if null - no constructor
+     * @param fieldCount  count of long fields
+     * @return class text
+     */
+    public static String generate(String className, String superClass, String constructor, long fieldCount) {
+
+        StringBuilder builder = new StringBuilder();
+        builder.append(String.format("public class %s%s {\n", className, superClass == null ? ""
+                : " extends " + superClass));
+
+        if (constructor != null) {
+            builder.append(constructor);
+        }
+
+        for (int i = 0; i < fieldCount; ++i) {
+            builder.append(String.format("long f%d;\n", i));
+        }
+
+        builder.append("}\n");
+        return builder.toString();
+    }
+
+    /**
+     * Changes string from enum notation to class notation - i.e. "VERY_SMALL_CAT" to "VerySmallCat"
+     *
+     * @param enumName string in enum notation
+     * @return string in class notation
+     */
+    public static String enumNameToClassName(String enumName) {
+        if (enumName == null) {
+            return null;
+        }
+
+        StringBuilder builder = new StringBuilder();
+        boolean toLowerCase = false;
+        for (int i = 0; i < enumName.length(); ++i) {
+            if (enumName.charAt(i) == '_') {
+                toLowerCase = false;
+            } else {
+                builder.append(toLowerCase ? String.valueOf(enumName.charAt(i)).toLowerCase() :
+                        String.valueOf(enumName.charAt(i)));
+                toLowerCase = true;
+            }
+
+        }
+        return builder.toString();
+    }
+
+    /**
+     * Generates and compiles class with instance of specified size and load it in specified class loader
+     * Generated class will looks like this:
+     * public class ClassName extends SuperClass {
+     * long f0;
+     * ...
+     * long fNNN;
+     * <p>
+     * }
+     *
+     * @param classLoader  class loader
+     * @param className    generated class name
+     * @param instanceSize size of generated class' instance. Size should be aligned by 8 bytes
+     * @param workDir      working dir where generated classes are put and compiled
+     * @param prefix       prefix for service classes (ones we use to create chain of inheritance).
+     *                     The names will be prefix_1, prefix_2,.., prefix_n
+     * @return Class object of generated and compiled class loaded in specified class loader
+     * @throws IOException
+     * @throws ClassNotFoundException
+     */
+    public static Class<?> generateCompileAndLoad(ClassLoader classLoader, String className, long instanceSize,
+                                                  Path workDir, String prefix)
+            throws IOException, ClassNotFoundException {
+
+        if (instanceSize % SIZE_OF_LONG != 0L) {
+            throw new Error(String.format("Test bug: only sizes aligned by 8 bytes are supported and %d was specified",
+                    instanceSize));
+        }
+
+        long instanceSizeWithoutObjectHeader = instanceSize - WhiteBox.getWhiteBox().getObjectSize(new Object());
+
+        int generatedClassesCount;
+        int fieldsInLastClassCount;
+
+        int sizeOfLastFile = (int) (instanceSizeWithoutObjectHeader
+                % (MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS * SIZE_OF_LONG));
+
+        if (sizeOfLastFile != 0) {
+            generatedClassesCount = (int) instanceSizeWithoutObjectHeader
+                    / (MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS * SIZE_OF_LONG) + 1;
+            fieldsInLastClassCount = sizeOfLastFile / SIZE_OF_LONG;
+        } else {
+            generatedClassesCount = (int) instanceSizeWithoutObjectHeader
+                    / (MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS * SIZE_OF_LONG);
+            fieldsInLastClassCount = MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS;
+        }
+
+        for (int i = 0; i < generatedClassesCount; i++) {
+            // for the last generated class we use specified class name
+            String clsName = (i == generatedClassesCount - 1) ? className : prefix + i;
+
+            Helpers.compileClass(clsName, workDir,
+                    Helpers.generate(
+                            clsName,
+                            // for first generated class we don't have 'extends'
+                            (i == 0 ? null : prefix + (i - 1)),
+                            null,
+                            // for the last generated class we use different field count
+                            (i == generatedClassesCount - 1) ? fieldsInLastClassCount
+                                    : MAXIMUM_AMOUNT_OF_FIELDS_IN_CLASS));
+        }
+        return classLoader.loadClass(className);
+    }
+
+    /**
+     * Waits until Concurent Mark Cycle finishes
+     * @param wb  Whitebox instance
+     * @param sleepTime sleep time
+     */
+    public static void waitTillCMCFinished(WhiteBox wb, int sleepTime) {
+        while (wb.g1InConcurrentMark()) {
+            if (sleepTime > -1) {
+                try {
+                    Thread.sleep(sleepTime);
+                } catch (InterruptedException e) {
+                    System.out.println("Got InterruptedException while waiting for ConcMarkCycle to finish");
+                    Thread.currentThread().interrupt();
+                    break;
+                }
+            }
+        }
+    }
+
+}