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 * 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

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 * You should have received a copy of the GNU General Public License version

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package gc.g1.humongousObjects;

import gc.testlibrary.Helpers;

import jdk.test.lib.Asserts;

import sun.hotspot.WhiteBox;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.net.URL;

import java.net.URLClassLoader;

import java.nio.file.Path;

import java.nio.file.Paths;

/**

 * @test gc.g1.humongousObjects.TestHumongousClassLoader

 * @summary Checks that unreachable classes and unreachable humongous class loader are unloaded after GC

 * @requires vm.gc.G1

 * @requires vm.opt.G1HeapRegionSize == "null" | vm.opt.G1HeapRegionSize == "1M"

 * @requires vm.opt.ExplicitGCInvokesConcurrent != true

 * @library /test/lib /

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

 * @modules java.management

 * @build sun.hotspot.WhiteBox

 * @run driver ClassFileInstaller sun.hotspot.WhiteBox

 *                                sun.hotspot.WhiteBox$WhiteBoxPermission

 *

 *                                gc.g1.humongousObjects.ClassLoaderGenerator 1

 *

 * @run main/othervm -Xms256M -Xmx256M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.

 *                   -Xlog:class+load,class+unload=debug:file=TestHumongousClassLoader_Full_GC.log

 *                   -XX:G1HeapRegionSize=1M

 *                   gc.g1.humongousObjects.TestHumongousClassLoader FULL_GC

 *

 * @run main/othervm -Xms256M -Xmx256M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.

 *                   -Xlog:class+load,class+unload=debug:file=TestHumongousClassLoader_Full_GC_Mem_Pressure.log

 *                   -XX:G1HeapRegionSize=1M

 *                   gc.g1.humongousObjects.TestHumongousClassLoader FULL_GC_MEMORY_PRESSURE

 *

 *@run main/othervm -Xms256M -Xmx256M -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.

 *                   -Xlog:class+load,class+unload=debug:file=TestHumongousClassLoader_CMC.log

 *                   -XX:G1HeapRegionSize=1M -XX:MaxTenuringThreshold=1

 *                   gc.g1.humongousObjects.TestHumongousClassLoader CMC

 *

 */

public class TestHumongousClassLoader {

    private static final WhiteBox WB = WhiteBox.getWhiteBox();

    private static final String SAMPLE_CLASS_NAME_PREFIX = "SampleClassFiller";

    public static final String SIMPLE_CLASSLOADER_NAME = "SimpleClassLoader";

    public static final String HUMONGOUS_CLASSLOADER_NAME = "HumongousClassLoader";

    public static final String LOAD_CLASS_METHOD_PROTOTYPE =

            "    @Override\n"

                    + "    public Class loadClass(String fileName) throws ClassNotFoundException {\n"

                    + "        if (${ClassLoadFilter}) {\n"

                    + "            System.out.println(\"Loading class \" + fileName);\n"

                    + "            byte[] b = null;\n"

                    + "            try {\n"

                    + "                b = Files.readAllBytes(new File(fileName + \".class\").toPath());\n"

                    + "            } catch (IOException e) {\n"

                    + "                e.printStackTrace();\n"

                    + "            }\n"

                    + "            Class c = defineClass(fileName, b, 0, b.length);\n"

                    + "            resolveClass(c);\n"

                    + "            return c;\n"

                    + "        } else {\n"

                    + "            return super.loadClass(fileName);\n"

                    + "        }\n"

                    + "\n"

                    + "\n"

                    + "    }\n";

    public static final String CLASS_HEADER = "import java.io.File;\n"

            + "import java.io.IOException;\n"

            + "import java.nio.file.Files;\n"

            + "import java.nio.file.Paths;\n";

    public static final String GENERIC_PROTOTYPE = "${ClassHeader}\n"

            + "public class ${ClassName} extends ${BaseClass}{\n"

            + "    ${ConstructorClause}\n"

            + "    ${Methods}\n"

            + "    ${Fields}\n"

            + "}\n";

    public static final String CONSTUCTOR_PROTOTYPE = "public ${ClassName}(ClassLoader parent) { super(parent);}\n";

    private enum GC {

        FULL_GC {

            @Override

            public void provoke() {

                System.gc();

            }

        },

        CMC {

            @Override

            public void provoke() {

                // We need 2 young gc to promote class loader to old gen

                // Otherwise it will not be unloaded after CMC

                WHITE_BOX.youngGC();

                Helpers.waitTillCMCFinished(WHITE_BOX, 0);

                WHITE_BOX.youngGC();

                Helpers.waitTillCMCFinished(WHITE_BOX, 0);

                WHITE_BOX.g1StartConcMarkCycle();

                Helpers.waitTillCMCFinished(WHITE_BOX, 0);

            }

        },

        FULL_GC_MEMORY_PRESSURE {

            @Override

            public void provoke() {

                WHITE_BOX.fullGC();

            }

        };

        private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();

        public abstract void provoke();

    }

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException,

            IllegalAccessException, IOException, NoSuchMethodException, InvocationTargetException {

        if (args.length != 1) {

            throw new Error("Test Bug: Expected GC type wasn't provided as command line argument");

        }

        GC gc = GC.valueOf(args[0]);

        Path wrkDir = Paths.get("");

        URL[] url = {wrkDir.toUri().toURL()};

        URLClassLoader urlLoader = new URLClassLoader(url);

        Class<?> simpleClassLoaderClass = urlLoader.loadClass(SIMPLE_CLASSLOADER_NAME);

        ClassLoader simpleClassLoader = (ClassLoader) simpleClassLoaderClass

                .getConstructor(java.lang.ClassLoader.class)

                .newInstance(TestHumongousClassLoader.class.getClassLoader());

        // Sanity check

        Asserts.assertEquals(WB.g1IsHumongous(simpleClassLoader), false,

                "Test Bug: simpleClassLoader is expected to be non-humongous but it's humongous");

        Class<?> humongousClassLoaderClass = simpleClassLoader.loadClass(HUMONGOUS_CLASSLOADER_NAME);

        ClassLoader humongousClassLoader = (ClassLoader) humongousClassLoaderClass

                .getConstructor(java.lang.ClassLoader.class)

                .newInstance(simpleClassLoader);

        // Sanity check

        Asserts.assertEquals(WB.g1IsHumongous(humongousClassLoader), true,

                "Test Bug: humongousClassLoader is expected to be humongous but it's non-humongous");

        //Asserts.assertEquals(1,0);

        Object[] loadedClasses = new Object[]{

                G1SampleClass.LARGEST_NON_HUMONGOUS.getCls(humongousClassLoader, wrkDir, SAMPLE_CLASS_NAME_PREFIX)

                        .newInstance(),

                G1SampleClass.SMALLEST_HUMONGOUS.getCls(humongousClassLoader, wrkDir, SAMPLE_CLASS_NAME_PREFIX)

                        .newInstance(),

                G1SampleClass.ONE_REGION_HUMONGOUS.getCls(humongousClassLoader, wrkDir, SAMPLE_CLASS_NAME_PREFIX)

                        .newInstance(),

                G1SampleClass.TWO_REGION_HUMONGOUS.getCls(humongousClassLoader, wrkDir, SAMPLE_CLASS_NAME_PREFIX)

                        .newInstance(),

        };

        // forgetting references to loaded classes

        for (int i = 0; i < loadedClasses.length; ++i) {

            loadedClasses[i] = null;

        }

        // forgetting referencies to classloaders

        humongousClassLoader = null;

        humongousClassLoaderClass = null;

        simpleClassLoader = null;

        simpleClassLoaderClass = null;

        gc.provoke();

        // Test checks

        Asserts.assertEquals(WB.isClassAlive(HUMONGOUS_CLASSLOADER_NAME), false,

                String.format("Classloader class %s is loaded after we forget all references to it",

                        HUMONGOUS_CLASSLOADER_NAME));

        for (G1SampleClass sampleClass : G1SampleClass.values()) {

            String className = Helpers.enumNameToClassName(sampleClass.name()) + "Class";

            Asserts.assertEquals(WB.isClassAlive(className), false,

                    String.format("Class %s is loaded after we forget all references to it", className));

        }

    }

}