test/hotspot/jtreg/runtime/HiddenClasses/InstantiateHiddenClass.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 */

/*
 * @test
 * @summary Test issues with instantiating hidden classes.
 * @library /test/lib
 * @modules jdk.compiler
 * @run main InstantiateHiddenClass
 */

import java.lang.invoke.MethodType;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodHandles.Lookup;
import java.lang.invoke.MethodHandles.Lookup.ClassOption;
import static java.lang.invoke.MethodHandles.Lookup.ClassOption.*;
import jdk.test.lib.compiler.InMemoryJavaCompiler;

public class InstantiateHiddenClass {

    static byte klassbuf[] = InMemoryJavaCompiler.compile("TestClass",
        "public class TestClass { " +
        "    public static void concat(String one, String two) throws Throwable { " +
        "        System.out.println(one + two);" +
        " } } ");

    public static void main(String[] args) throws Throwable {
        // This class is also used by the appcds/dynamicArchive/RegularHiddenClass.java
        // test which will pass the "keep-alive" argument during dynamic CDS dump
        // for preventing from being GC'ed prior to the dumping operation.
        boolean keepAlive = false;
        if (args.length == 1 && args[0].equals("keep-alive")) {
            keepAlive = true;
        }

        // Test that a hidden class cannot be found through its name.
        try {
            Lookup lookup = MethodHandles.lookup();
            Class<?> c0 = lookup.defineHiddenClass(klassbuf, false, NESTMATE).lookupClass();
            Class.forName(c0.getName()).newInstance();
            throw new RuntimeException("Expected ClassNotFoundException not thrown");
        } catch (ClassNotFoundException e ) {
            // Test passed
        }


        // Create two hidden classes and instantiate an object from each of them.
        // Verify that the references to these objects are different and references
        // to their classes are not equal either.
        Lookup lookup = MethodHandles.lookup();
        ClassOption classOption = keepAlive ? STRONG : NESTMATE;
        Class<?> c1 = lookup.defineHiddenClass(klassbuf, false, classOption).lookupClass();
        Class<?> c2 = lookup.defineHiddenClass(klassbuf, false, classOption).lookupClass();
        Object o1 = c1.newInstance();
        Object o2 = c2.newInstance();
        if (o1 == o2) {
            throw new RuntimeException("Objects should not be equal");
        }
        if (o1.getClass() == o2.getClass()) {
            throw new RuntimeException("Classes should not be equal");
        }
    }
}