parallelLockMap keeps growing

FULL PRODUCT VERSION :
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux hpslim.skynet 3.2.0-58-generic #88-Ubuntu SMP Tue Dec 3 17:37:58 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux


A DESCRIPTION OF THE PROBLEM :
I have a stress test case that shows that the field sun.misc.Launcher$AppClassLoader.parallelLockMap grows until "java.lang.OutOfMemoryError: Java heap space" happens, this error does not happen on version 1.6.0_27


REGRESSION. Last worked in version 6u43

ADDITIONAL REGRESSION INFORMATION:
java version "1.6.0_27"
OpenJDK Runtime Environment (IcedTea6 1.12.6) (6b27-1.12.6-1ubuntu0.12.04.4)
OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode)


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
java -ea -XX:MaxPermSize=30m -Xms8m -Xmx64m -XX:+HeapDumpOnOutOfMemoryError test01


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
on 1.6.0_27 the program cleanly exit with "all done" message

ACTUAL -
java.lang.OutOfMemoryError: Java heap space
Dumping heap to java_pid27708.hprof ...
Heap dump file created [87922226 bytes in 0.956 secs]
Java heap space


ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.OutOfMemoryError: Java heap space


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------

import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;

import java.lang.reflect.Constructor;

public class test01 {
    void doit(String[] args) throws Exception {
        test01classmaker cm = new test01classmaker();
        ClassLoader thiscl = getClass().getClassLoader();
        test01cl clsloader = new test01cl(thiscl, cm);
        for (int i=0; i<1000000; i++) {
            String className = String.format("Class%04d", i);
            clsloader.loadClass(className);
            if ((i % 1000) == 0) {
                /* discard old class loader */
                clsloader = new test01cl(thiscl, cm);
            }
        }
    }
    public static void main(String[] args) throws Exception {
        try {
            new test01().doit(args);
        } catch (OutOfMemoryError e) {
            System.out.println(e.getMessage());
            System.exit(1);
        }
        System.out.println("all done");
    }
    public String greeting() {
        return "";
    }
}

class test01classmaker implements Opcodes {
    byte[] makeClass(String className) {
        String superName = "test01";

        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES + ClassWriter.COMPUTE_MAXS);
        cw.visit(V1_6, ACC_PUBLIC, className, null, superName, null);

        MethodVisitor mw = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mw.visitVarInsn(ALOAD, 0);
        mw.visitMethodInsn(INVOKESPECIAL, superName, "<init>", "()V");
        mw.visitInsn(RETURN);
        mw.visitMaxs(0,0);
        mw.visitEnd();

        mw = cw.visitMethod(ACC_PUBLIC, "greeting", "()Ljava/lang/String;", null, null);
        mw.visitLdcInsn(String.format("hello world! (from %s)", className));
        mw.visitInsn(ARETURN);
        mw.visitMaxs(0,0);
        mw.visitEnd();

        cw.visitEnd();

        return cw.toByteArray();
    }
}

class test01cl extends ClassLoader {
    test01classmaker cm;
    protected test01cl(ClassLoader parent, test01classmaker cm) {
        super(parent);
        this.cm = cm;
    }
    @Override
    protected Class<?> findClass(String name) throws ClassNotFoundException {
        Class<?> c;
        if (name.startsWith("Class") && Integer.parseInt(name.substring(5)) >= 0) {
            byte[] code = cm.makeClass(name);
            c = defineClass(name, code, 0, code.length);
        } else {
            c = super.findClass(name);
        }
        return c;
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
no known workaround