--- /dev/null	2020-01-02 04:43:18.583999853 +0000
+++ new/test/jdk/jfr/event/runtime/TestClassLoadingStatisticsEvent.java	2020-01-30 06:35:12.106400621 +0000
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2013, 2018, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 jdk.jfr.event.runtime;
+
+import java.util.List;
+
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.test.lib.Asserts;
+import jdk.test.lib.jfr.EventNames;
+import jdk.test.lib.jfr.Events;
+import jdk.test.lib.jfr.TestClassLoader;
+
+/**
+ * @test
+ * @key jfr
+ *
+ * @library /lib /
+ * @build jdk.jfr.event.runtime.TestClasses
+ * @run main/othervm jdk.jfr.event.runtime.TestClassLoadingStatisticsEvent
+ */
+/**
+ * This test will load a number of classes. After each load step we verify that
+ * the loadedClassCount and unloadedClassCount attributes are correct.
+ *
+ * System.gc() will trigger class unloading if -XX:+ExplicitGCInvokesConcurrent
+ * is NOT set. If this flag is set G1 will never unload classes on System.gc()
+ * and CMS will not guarantee that all semantically dead classes will be
+ * unloaded. As far as the "jfr" key guarantees no VM flags are set from the
+ * outside it should be enough with System.gc().
+ */
+public class TestClassLoadingStatisticsEvent {
+
+    private final static String EVENT_PATH = EventNames.ClassLoadingStatistics;
+    private final static String TESTCLASS_PUBLIC_STATIC =
+                "jdk.jfr.event.runtime.TestClasses$TestClassPublicStatic";
+    private final static String TESTCLASS_PUBLIC_STATIC_INNER =
+                "jdk.jfr.event.runtime.TestClasses$TestClassPublicStatic$TestClassPublicStaticInner";
+
+    // Declare unloadableClassLoader as "public static"
+    // to prevent the compiler to optimize away all unread writes
+    public static TestClassLoader unloadableClassLoader;
+
+    public static void main(String[] args) throws Throwable {
+        // Load twice to get more stable result.
+        RecordedEvent event = getCurrentEvent();
+        event = getCurrentEvent();
+
+        // Declare class ClassLoadingStatisticsHelper.
+        TestClasses[] helpers = new TestClasses[10];
+        event = verifyCountDelta(event, 1, 0);
+
+        // Should load classes TestClassPrivate and TestClassPrivateStatic.
+        for (int c = 0; c < helpers.length; c++) {
+            helpers[c] = new TestClasses();
+        }
+        event = verifyCountDelta(event, 2, 0);
+
+        // Load classes TestClassProtected and B2.
+        helpers[0].new TestClassProtected();
+        helpers[1].new TestClassProtected(); // This class is already loaded.
+        new TestClasses.TestClassProtectedStatic();
+        event = verifyCountDelta(event, 2, 0);
+
+        // Load classes TestClassProtected1 and TestClassProtectedStatic1.
+        for (int c = 0; c < helpers.length; c++) {
+            helpers[c].loadClasses();
+        }
+        event = verifyCountDelta(event, 2, 0);
+
+        // Load the classes with separate class loader. Will be unloaded later.
+        unloadableClassLoader = new TestClassLoader();
+
+        unloadableClassLoader.loadClass(TESTCLASS_PUBLIC_STATIC_INNER);
+        event = verifyCountDelta(event, 1, 0);
+
+        unloadableClassLoader.loadClass(TESTCLASS_PUBLIC_STATIC);
+        event = verifyCountDelta(event, 1, 0);
+
+        // This System.gc() should not unload classes, since the
+        // unloadableClassLoader object is still active.
+        System.gc();
+        event = verifyCountDelta(event, 0, 0);
+
+        // make classes are unloaded.
+        unloadableClassLoader = null;
+        System.gc();
+        event = verifyCountDelta(event, 0, 2);
+    }
+
+    private static RecordedEvent getCurrentEvent() throws Throwable {
+        Recording recording = new Recording();
+        recording.enable(EVENT_PATH);
+        recording.start();
+        recording.stop();
+        List<RecordedEvent> events = Events.fromRecording(recording);
+        Asserts.assertFalse(events.isEmpty(), "No events in recording");
+        RecordedEvent event = events.get(0);
+        return event;
+    }
+
+    private static RecordedEvent verifyCountDelta(
+        RecordedEvent prevEvent, int loadDelta, int unloadDelta) throws Throwable {
+        RecordedEvent currEvent = null;
+        try {
+            long prevLoad = Events.assertField(prevEvent, "loadedClassCount").getValue();
+            long prevUnload = Events.assertField(prevEvent, "unloadedClassCount").getValue();
+
+            currEvent = getCurrentEvent();
+            Events.assertField(currEvent, "loadedClassCount").atLeast(prevLoad + loadDelta);
+            Events.assertField(currEvent, "unloadedClassCount").atLeast(prevUnload + unloadDelta);
+            return currEvent;
+        } catch (Throwable t) {
+            System.out.println("verifyCountDelta failed. prevEvent=" + prevEvent + ", currEvent=" + currEvent);
+            throw t;
+        }
+    }
+
+}